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1 | \input texinfo |
2 | @c Notes to self regarding line handling: | |
3 | @c | |
4 | @c Empty lines are often significant before @end directives; avoid them. | |
5 | @c | |
6 | @c Empty lines before and after @example directives are significant in | |
7 | @c info output but not in TeX. Empty lines inside @example directives | |
8 | @c are significant. | |
9 | ||
10 | @c Conventions for formatting examples: | |
11 | @c o If the example contains empty lines then put the surrounding empty | |
12 | @c lines inside the @example directives. Put them outside otherwise. | |
13 | @c o Use @group inside the example only if it shows indentation where | |
14 | @c the relation between lines inside is relevant. | |
15 | @c o Format line number columns like this: | |
16 | @c 1: foo | |
17 | @c 2: bar | |
18 | @c ^ one space | |
19 | @c ^^ two columns, right alignment | |
20 | @c o Check line lengths in TeX output; they can typically be no longer | |
21 | @c than 70 chars, 60 if the paragraph is indented. | |
22 | ||
23 | @comment TBD: Document the finer details of statement anchoring? | |
24 | ||
25 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
26 | @comment %**start of header (This is for running Texinfo on a region) | |
27 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
28 | ||
29 | ||
30 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
31 | @comment How to make the various output formats: | |
32 | @comment (Thanks to Robert Chassell for supplying this information.) | |
33 | @comment Note that Texinfo 4.7 (or later) is needed. | |
34 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
35 | @ignore | |
36 | In each of the following pairs of commands, the first generates a | |
37 | version with cross references pointing to the GNU Emacs manuals, | |
38 | the second with them pointing to the XEmacs manuals. | |
39 | ## Info output | |
40 | makeinfo cc-mode.texi | |
41 | makeinfo -DXEMACS cc-mode.texi | |
42 | ||
43 | ## DVI output | |
44 | ## You may need to set up the environment variable TEXINPUTS so | |
45 | ## that tex can find the file texinfo.tex - See the tex | |
46 | ## manpage. | |
47 | texi2dvi cc-mode.texi | |
48 | texi2dvi -t "@set XEMACS " cc-mode.texi | |
49 | ||
50 | ## HTML output. (The --no-split parameter is optional) | |
51 | makeinfo --html --no-split cc-mode.texi | |
52 | makeinfo --html --no-split -DXEMACS cc-mode.texi | |
53 | ||
54 | ## Plain text output | |
55 | makeinfo --fill-column=70 --no-split --paragraph-indent=0 \ | |
56 | --no-headers --output=cc-mode.txt cc-mode.texi | |
57 | makeinfo --fill-column=70 --no-split --paragraph-indent=0 \ | |
58 | --no-headers --output=cc-mode.txt -DXEMACS cc-mode.texi | |
59 | ||
60 | ## DocBook output | |
61 | makeinfo --docbook --no-split --paragraph-indent=0 \ | |
62 | cc-mode.texi | |
63 | makeinfo --docbook --no-split --paragraph-indent=0 \ | |
64 | -DXEMACS cc-mode.texi | |
65 | ||
66 | ## XML output | |
67 | makeinfo --xml --no-split --paragraph-indent=0 \ | |
68 | cc-mode.texi | |
69 | makeinfo --xml --no-split --paragraph-indent=0 \ | |
70 | -DXEMACS cc-mode.texi | |
71 | ||
72 | #### (You must be in the same directory as the viewed file.) | |
73 | ||
74 | ## View DVI output | |
75 | xdvi cc-mode.dvi & | |
76 | ||
77 | ## View HTML output | |
78 | mozilla cc-mode.html | |
79 | @end ignore | |
80 | ||
81 | @comment No overfull hbox marks in the dvi file. | |
82 | @finalout | |
83 | ||
db78a8cb | 84 | @setfilename ../../info/ccmode |
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85 | @settitle CC Mode Manual |
86 | @footnotestyle end | |
87 | ||
88 | @c The following four macros generate the filenames and titles of the | |
89 | @c main (X)Emacs manual and the Elisp/Lispref manual. Leave the | |
90 | @c Texinfo variable `XEMACS' unset to generate a GNU Emacs version, set it | |
91 | @c to generate an XEmacs version, e.g. with | |
92 | @c "makeinfo -DXEMACS cc-mode.texi". | |
93 | @ifset XEMACS | |
94 | @macro emacsman | |
95 | xemacs | |
96 | @end macro | |
97 | @macro emacsmantitle | |
98 | XEmacs User's Manual | |
99 | @end macro | |
100 | @macro lispref | |
101 | lispref | |
102 | @end macro | |
103 | @macro lispreftitle | |
104 | XEmacs Lisp Reference Manual | |
105 | @end macro | |
106 | @end ifset | |
107 | ||
108 | @ifclear XEMACS | |
109 | @macro emacsman | |
110 | emacs | |
111 | @end macro | |
112 | @macro emacsmantitle | |
113 | GNU Emacs Manual | |
114 | @end macro | |
115 | @macro lispref | |
116 | elisp | |
117 | @end macro | |
118 | @macro lispreftitle | |
119 | GNU Emacs Lisp Reference Manual | |
120 | @end macro | |
121 | @end ifclear | |
122 | ||
123 | ||
124 | @macro ccmode | |
125 | CC Mode | |
126 | @end macro | |
127 | ||
128 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
129 | @comment @setchapternewpage odd !! we don't want blank pages !! | |
130 | @comment %**end of header (This is for running Texinfo on a region) | |
131 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
132 | ||
133 | ||
134 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
135 | @comment | |
136 | @comment Texinfo manual for CC Mode | |
137 | @comment Generated from the original README file by Krishna Padmasola | |
138 | @comment <krishna@earth-gw.njit.edu> | |
139 | @comment | |
140 | @comment Authors: | |
141 | @comment Barry A. Warsaw | |
142 | @comment Martin Stjernholm | |
143 | @comment Alan Mackenzie | |
144 | @comment | |
145 | @comment Maintained by Martin Stjernholm and Alan Mackenzie <bug-cc-mode@gnu.org> | |
146 | @comment | |
147 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
148 | ||
149 | @comment Define an index for syntactic symbols. | |
150 | @ifnottex @c In texi2dvi, the @defindex would create an empty cc-mode.ss | |
151 | @c For Info, unlike tex, @syncodeindex needs a matching @defindex. | |
152 | @defindex ss | |
153 | @end ifnottex | |
154 | ||
155 | @comment Combine key, syntactic symbol and concept indices into one. | |
156 | @syncodeindex ss cp | |
157 | @syncodeindex ky cp | |
158 | ||
159 | @copying | |
160 | This manual is for CC Mode in Emacs. | |
161 | ||
73b0cd50 | 162 | Copyright @copyright{} 1995-2011 Free Software Foundation, Inc. |
4009494e GM |
163 | |
164 | @quotation | |
165 | Permission is granted to copy, distribute and/or modify this document | |
6a2c4aec | 166 | under the terms of the GNU Free Documentation License, Version 1.3 or |
7b2d06e1 GM |
167 | any later version published by the Free Software Foundation; with no |
168 | Invariant Sections, with the Front-Cover texts being ``A GNU Manual'', | |
169 | and with the Back-Cover Texts as in (a) below. A copy of the license | |
170 | is included in the section entitled ``GNU Free Documentation License''. | |
4009494e | 171 | |
6f093307 GM |
172 | (a) The FSF's Back-Cover Text is: ``You have the freedom to copy and |
173 | modify this GNU manual. Buying copies from the FSF supports it in | |
174 | developing GNU and promoting software freedom.'' | |
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175 | @end quotation |
176 | @end copying | |
177 | ||
178 | @comment Info directory entry for use by install-info. The indentation | |
179 | @comment here is by request from the FSF folks. | |
0c973505 | 180 | @dircategory Emacs editing modes |
4009494e | 181 | @direntry |
62e034c2 GM |
182 | * CC Mode: (ccmode). Emacs mode for editing C, C++, Objective-C, |
183 | Java, Pike, AWK, and CORBA IDL code. | |
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184 | @end direntry |
185 | ||
186 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
187 | @comment TeX title page | |
188 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
189 | ||
190 | @titlepage | |
191 | @sp 10 | |
192 | ||
47d42d81 | 193 | @center @titlefont{CC Mode 5.32} |
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194 | @sp 2 |
195 | @center @subtitlefont{A GNU Emacs mode for editing C and C-like languages} | |
196 | @sp 2 | |
197 | @center Barry A. Warsaw, Martin Stjernholm, Alan Mackenzie | |
198 | ||
199 | @page | |
200 | @vskip 0pt plus 1filll | |
201 | @insertcopying | |
202 | ||
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203 | This manual was generated from cc-mode.texi, which is distributed with Emacs, |
204 | or can be downloaded from @url{http://savannah.gnu.org/projects/emacs/}. | |
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205 | @end titlepage |
206 | ||
207 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
208 | @comment The Top node contains the master menu for the Info file. | |
209 | @comment This appears only in the Info file, not the printed manual. | |
210 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
211 | ||
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212 | @summarycontents |
213 | @contents | |
214 | ||
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215 | @node Top, Introduction, (dir), (dir) |
216 | @comment node-name, next, previous, up | |
217 | ||
5dc584b5 | 218 | @ifnottex |
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219 | @top @ccmode{} |
220 | ||
221 | @ccmode{} is a GNU Emacs mode for editing files containing C, C++, | |
222 | Objective-C, Java, CORBA IDL (and the variants PSDL and CIDL), Pike | |
223 | and AWK code. It provides syntax-based indentation, font locking, and | |
224 | has several handy commands and some minor modes to make the editing | |
225 | easier. It does not provide tools to look up and navigate between | |
226 | functions, classes etc - there are other packages for that. | |
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227 | |
228 | @insertcopying | |
229 | @end ifnottex | |
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230 | |
231 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
232 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
233 | ||
234 | @menu | |
235 | * Introduction:: | |
236 | * Overview:: | |
237 | * Getting Started:: | |
238 | * Commands:: | |
239 | * Font Locking:: | |
240 | * Config Basics:: | |
241 | * Custom Filling and Breaking:: | |
242 | * Custom Auto-newlines:: | |
243 | * Clean-ups:: | |
244 | * Indentation Engine Basics:: | |
245 | * Customizing Indentation:: | |
246 | * Custom Macros:: | |
247 | * Odds and Ends:: | |
248 | * Sample .emacs File:: | |
249 | * Performance Issues:: | |
250 | * Limitations and Known Bugs:: | |
251 | * FAQ:: | |
252 | * Updating CC Mode:: | |
253 | * Mailing Lists and Bug Reports:: | |
254 | * GNU Free Documentation License:: | |
255 | * Command and Function Index:: | |
256 | * Variable Index:: | |
257 | * Concept and Key Index:: | |
258 | ||
259 | @detailmenu | |
260 | --- The Detailed Node Listing --- | |
261 | ||
262 | Commands | |
263 | ||
264 | * Indentation Commands:: | |
265 | * Comment Commands:: | |
266 | * Movement Commands:: | |
267 | * Filling and Breaking:: | |
268 | * Minor Modes:: | |
269 | * Electric Keys:: | |
270 | * Auto-newlines:: | |
271 | * Hungry WS Deletion:: | |
272 | * Subword Movement:: | |
273 | * Other Commands:: | |
274 | ||
275 | Font Locking | |
276 | ||
277 | * Font Locking Preliminaries:: | |
278 | * Faces:: | |
279 | * Doc Comments:: | |
280 | * AWK Mode Font Locking:: | |
281 | ||
282 | Configuration Basics | |
283 | ||
284 | * CC Hooks:: | |
285 | * Style Variables:: | |
286 | * Styles:: | |
287 | ||
288 | Styles | |
289 | ||
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290 | * Built-in Styles:: |
291 | * Choosing a Style:: | |
292 | * Adding Styles:: | |
293 | * Guessing the Style:: | |
294 | * File Styles:: | |
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295 | |
296 | Customizing Auto-newlines | |
297 | ||
298 | * Hanging Braces:: | |
299 | * Hanging Colons:: | |
300 | * Hanging Semicolons and Commas:: | |
301 | ||
302 | Hanging Braces | |
303 | ||
304 | * Custom Braces:: | |
305 | ||
306 | Indentation Engine Basics | |
307 | ||
308 | * Syntactic Analysis:: | |
309 | * Syntactic Symbols:: | |
310 | * Indentation Calculation:: | |
311 | ||
312 | Syntactic Symbols | |
313 | ||
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314 | * Function Symbols:: |
315 | * Class Symbols:: | |
316 | * Conditional Construct Symbols:: | |
317 | * Switch Statement Symbols:: | |
318 | * Brace List Symbols:: | |
319 | * External Scope Symbols:: | |
320 | * Paren List Symbols:: | |
321 | * Literal Symbols:: | |
322 | * Multiline Macro Symbols:: | |
323 | * Objective-C Method Symbols:: | |
5cee0a9c | 324 | * Java Symbols:: |
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325 | * Statement Block Symbols:: |
326 | * K&R Symbols:: | |
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327 | |
328 | Customizing Indentation | |
329 | ||
330 | * c-offsets-alist:: | |
331 | * Interactive Customization:: | |
332 | * Line-Up Functions:: | |
333 | * Custom Line-Up:: | |
334 | * Other Indentation:: | |
335 | ||
336 | Line-Up Functions | |
337 | ||
338 | * Brace/Paren Line-Up:: | |
339 | * List Line-Up:: | |
340 | * Operator Line-Up:: | |
341 | * Comment Line-Up:: | |
342 | * Misc Line-Up:: | |
343 | ||
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344 | Customizing Macros |
345 | ||
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346 | * Macro Backslashes:: |
347 | * Macros with ;:: | |
536610a4 | 348 | |
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349 | @end detailmenu |
350 | @end menu | |
351 | ||
352 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
353 | @node Introduction, Overview, Top, Top | |
354 | @comment node-name, next, previous, up | |
355 | @chapter Introduction | |
356 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
357 | ||
358 | @cindex BOCM | |
359 | @cindex history | |
360 | @cindex awk-mode.el | |
361 | @cindex c-mode.el | |
362 | @cindex c++-mode.el | |
363 | ||
364 | Welcome to @ccmode{}, a GNU Emacs mode for editing files containing C, | |
365 | C++, Objective-C, Java, CORBA IDL (and the variants CORBA PSDL and | |
366 | CIDL), Pike and AWK code. This incarnation of the mode is descended | |
367 | from @file{c-mode.el} (also called ``Boring Old C Mode'' or BOCM | |
368 | @t{:-)}, @file{c++-mode.el} version 2, which Barry Warsaw had been | |
369 | maintaining since 1992, and @file{awk-mode.el}, a long neglected mode | |
370 | in the (X)Emacs base. | |
371 | ||
372 | Late in 1997, Martin Stjernholm joined Barry on the @ccmode{} | |
373 | Maintainers Team, and implemented the Pike support. In 2000 Martin | |
374 | took over as the sole maintainer. In 2001 Alan Mackenzie joined the | |
375 | team, implementing AWK support in version 5.30. @ccmode{} did not | |
376 | originally contain the font lock support for its languages --- that | |
377 | was added in version 5.30. | |
378 | ||
379 | This manual describes @ccmode{} | |
380 | @comment The following line must appear on its own, so that the | |
47d42d81 | 381 | version 5.32. |
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382 | @comment Release.py script can update the version number automatically |
383 | ||
384 | @ccmode{} supports the editing of K&R and ANSI C, C++, Objective-C, | |
385 | Java, CORBA's Interface Definition Language, Pike@footnote{A C-like | |
386 | scripting language with its roots in the LPC language used in some MUD | |
387 | engines. See @uref{http://pike.ida.liu.se/}.} and AWK files. In this | |
388 | way, you can easily set up consistent font locking and coding styles for | |
389 | use in editing all of these languages, although AWK is not yet as | |
390 | uniformly integrated as the other languages. | |
391 | ||
392 | @findex c-mode | |
393 | @findex c++-mode | |
394 | @findex objc-mode | |
395 | @findex java-mode | |
396 | @findex idl-mode | |
397 | @findex pike-mode | |
398 | @findex awk-mode | |
399 | Note that the name of this package is ``@ccmode{}'', but there is no top | |
400 | level @code{cc-mode} entry point. All of the variables, commands, and | |
401 | functions in @ccmode{} are prefixed with @code{c-@var{thing}}, and | |
402 | @code{c-mode}, @code{c++-mode}, @code{objc-mode}, @code{java-mode}, | |
403 | @code{idl-mode}, @code{pike-mode}, and @code{awk-mode} entry points are | |
404 | provided. This package is intended to be a replacement for | |
405 | @file{c-mode.el}, @file{c++-mode.el} and @file{awk-mode.el}. | |
406 | ||
407 | A special word of thanks goes to Krishna Padmasola for his work in | |
408 | converting the original @file{README} file to Texinfo format. I'd | |
409 | also like to thank all the @ccmode{} victims who help enormously | |
410 | during the early beta stages of @ccmode{}'s development. | |
411 | ||
412 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
413 | @node Overview, Getting Started, Introduction, Top | |
414 | @comment node-name, next, previous, up@cindex organization of the manual | |
415 | @chapter Overview of the Manual | |
416 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
417 | ||
418 | @noindent | |
419 | The manual starts with several introductory chapters (including this | |
420 | one). | |
421 | ||
422 | @noindent | |
423 | The next chunk of the manual describes the day to day @emph{use} of | |
424 | @ccmode{} (as contrasted with how to customize it). | |
425 | ||
426 | @itemize @bullet | |
427 | @item | |
428 | The chapter ``Commands'' describes in detail how to use (nearly) all | |
429 | of @ccmode{}'s features. There are extensive cross-references from | |
430 | here to the corresponding sections later in the manual which tell you | |
431 | how to customize these features. | |
432 | ||
433 | @item | |
434 | ``Font Locking'' describes how ``syntax highlighting'' is applied to | |
435 | your buffers. It is mainly background information and can be skipped | |
436 | over at a first reading. | |
437 | @end itemize | |
438 | ||
439 | @noindent | |
440 | The next chunk of the manual describes how to @emph{customize} | |
441 | @ccmode{}. Typically, an overview of a topic is given at the chapter | |
442 | level, then the sections and subsections describe the material in | |
443 | increasing detail. | |
444 | ||
445 | @itemize @bullet | |
446 | @item | |
447 | The chapter ``Configuration Basics'' tells you @emph{how} to write | |
448 | customizations - whether in hooks, in styles, in both, or in neither, | |
449 | depending on your needs. It describes the @ccmode{} style system and | |
450 | lists the standard styles that @ccmode{} supplies. | |
451 | ||
452 | @item | |
453 | The next few chapters describe in detail how to customize the various | |
454 | features of @ccmode{}. | |
455 | ||
456 | @item | |
457 | Finally, there is a sample @file{.emacs} fragment, which might help you | |
458 | in creating your own customization. | |
459 | @end itemize | |
460 | ||
461 | @noindent | |
462 | The manual ends with ``this and that'', things that don't fit cleanly | |
463 | into any of the previous chunks. | |
464 | ||
465 | @itemize @bullet | |
466 | @item | |
467 | Two chapters discuss the performance of @ccmode{} and known | |
468 | bugs/limitations. | |
469 | ||
470 | @item | |
471 | The FAQ contains a list of common problems and questions. | |
472 | ||
473 | @item | |
474 | The next two chapters tell you how to get in touch with the @ccmode{} | |
475 | project - whether for updating @ccmode{} or submitting bug reports. | |
476 | @end itemize | |
477 | ||
478 | @noindent | |
479 | Finally, there are the customary indices. | |
480 | ||
481 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
482 | @node Getting Started, Commands, Overview, Top | |
483 | @comment node-name, next, previous, up | |
484 | @chapter Getting Started | |
485 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
486 | ||
487 | If you got this version of @ccmode{} with Emacs or XEmacs, it should | |
488 | work just fine right out of the box. Note however that you might not | |
489 | have the latest @ccmode{} release and might want to upgrade your copy | |
490 | (see below). | |
491 | ||
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492 | You should probably start by skimming through the entire Commands chapter |
493 | (@pxref{Commands}) to get an overview of @ccmode{}'s capabilities. | |
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494 | |
495 | After trying out some commands, you may dislike some aspects of | |
496 | @ccmode{}'s default configuration. Here is an outline of how to | |
497 | change some of the settings that newcomers to @ccmode{} most often | |
498 | want to change: | |
499 | ||
500 | @table @asis | |
501 | @item c-basic-offset | |
502 | This Lisp variable holds an integer, the number of columns @ccmode{} | |
503 | indents nested code. To set this value to 6, customize | |
504 | @code{c-basic-offset} or put this into your @file{.emacs}: | |
505 | ||
506 | @example | |
507 | (setq c-basic-offset 6) | |
508 | @end example | |
509 | ||
510 | @item The (indentation) style | |
511 | The basic ``shape'' of indentation created by @ccmode{}---by default, | |
512 | this is @code{gnu} style (except for Java and AWK buffers). A list of | |
513 | the available styles and their descriptions can be found in | |
514 | @ref{Built-in Styles}. A complete specification of the @ccmode{} | |
515 | style system, including how to create your own style, can be found in | |
516 | the chapter @ref{Styles}. To set your style to @code{linux}, either | |
517 | customize @code{c-default-style} or put this into your @file{.emacs}: | |
518 | ||
519 | @example | |
520 | (setq c-default-style '((java-mode . "java") | |
521 | (awk-mode . "awk") | |
522 | (other . "linux"))) | |
523 | @end example | |
524 | ||
525 | @item Electric Indentation | |
526 | Normally, when you type ``punctuation'' characters such as @samp{;} or | |
527 | @samp{@{}, @ccmode{} instantly reindents the current line. This can | |
528 | be disconcerting until you get used to it. To disable @dfn{electric | |
529 | indentation} in the current buffer, type @kbd{C-c C-l}. Type the same | |
530 | thing to enable it again. To have electric indentation disabled by | |
531 | default, put the following into your @file{.emacs} file@footnote{There | |
532 | is no ``easy customization'' facility for making this change.}: | |
533 | ||
534 | @example | |
535 | (setq-default c-electric-flag nil) | |
536 | @end example | |
537 | ||
538 | @noindent | |
539 | Details of this and other similar ``Minor Modes'' appear in the | |
540 | section @ref{Minor Modes}. | |
541 | ||
542 | @item Making the @key{RET} key indent the new line | |
543 | The standard Emacs binding for @key{RET} just adds a new line. If you | |
544 | want it to reindent the new line as well, rebind the key. Note that | |
545 | the action of rebinding would fail if the pertinent keymap didn't yet | |
546 | exist---we thus need to delay the action until after @ccmode{} has | |
547 | been loaded. Put the following code into your @file{.emacs}: | |
548 | ||
549 | @example | |
550 | (defun my-make-CR-do-indent () | |
551 | (define-key c-mode-base-map "\C-m" 'c-context-line-break)) | |
552 | (add-hook 'c-initialization-hook 'my-make-CR-do-indent) | |
553 | @end example | |
554 | ||
555 | @noindent | |
556 | This example demonstrates the use of a very powerful @ccmode{} (and | |
557 | Emacs) facility, the hook. The use of @ccmode{}'s hooks is described | |
558 | in @ref{CC Hooks}. | |
559 | @end table | |
560 | ||
561 | All these settings should occur in your @file{.emacs} @emph{before} | |
562 | any @ccmode{} buffers get loaded---in particular, before any call of | |
563 | @code{desktop-read}. | |
564 | ||
565 | As you get to know the mode better, you may want to make more | |
566 | ambitious changes to your configuration. For this, you should start | |
567 | reading the chapter @ref{Config Basics}. | |
568 | ||
569 | If you are upgrading an existing @ccmode{} installation, please see | |
570 | the @file{README} file for installation details. In particular, if | |
571 | you are going to be editing AWK files, @file{README} describes how to | |
572 | configure your (X)Emacs so that @ccmode{} will supersede the obsolete | |
573 | @code{awk-mode.el} which might have been supplied with your (X)Emacs. | |
574 | @ccmode{} might not work with older versions of Emacs or XEmacs. See | |
575 | the @ccmode{} release notes at @uref{http://cc-mode.sourceforge.net} | |
576 | for the latest information on Emacs version and package compatibility | |
577 | (@pxref{Updating CC Mode}). | |
578 | ||
579 | @deffn Command c-version | |
580 | @findex version (c-) | |
581 | You can find out what version of @ccmode{} you are using by visiting a C | |
582 | file and entering @kbd{M-x c-version RET}. You should see this message in | |
583 | the echo area: | |
584 | ||
585 | @example | |
586 | Using CC Mode version 5.XX | |
587 | @end example | |
588 | ||
589 | @noindent | |
590 | where @samp{XX} is the minor release number. | |
591 | @end deffn | |
592 | ||
593 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
594 | @node Commands, Font Locking, Getting Started, Top | |
595 | @comment node-name, next, previous, up | |
596 | @chapter Commands | |
597 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
598 | ||
599 | This chapter specifies all of CC Mode's commands, and thus contains | |
600 | nearly everything you need to know to @emph{use} @ccmode{} (as | |
601 | contrasted with configuring it). @dfn{Commands} here means both | |
602 | control key sequences and @dfn{electric keys}, these being characters | |
603 | such as @samp{;} which, as well as inserting themselves into the | |
604 | buffer, also do other things. | |
605 | ||
606 | You might well want to review | |
607 | @ifset XEMACS | |
608 | @ref{Lists,,,@emacsman{}, @emacsmantitle{}}, | |
609 | @end ifset | |
610 | @ifclear XEMACS | |
611 | @ref{Moving by Parens,,,@emacsman{}, @emacsmantitle{}}, | |
612 | @end ifclear | |
613 | which describes commands for moving around brace and parenthesis | |
614 | structures. | |
615 | ||
616 | ||
617 | @menu | |
618 | * Indentation Commands:: | |
619 | * Comment Commands:: | |
620 | * Movement Commands:: | |
621 | * Filling and Breaking:: | |
622 | * Minor Modes:: | |
623 | * Electric Keys:: | |
624 | * Auto-newlines:: | |
625 | * Hungry WS Deletion:: | |
626 | * Subword Movement:: | |
627 | * Other Commands:: | |
628 | @end menu | |
629 | ||
630 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
631 | @node Indentation Commands, Comment Commands, Commands, Commands | |
632 | @comment node-name, next, previous,up | |
633 | @section Indentation Commands | |
634 | @cindex indentation | |
635 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
636 | ||
637 | The following commands reindent C constructs. Note that when you | |
638 | change your coding style, either interactively or through some other | |
639 | means, your file does @emph{not} automatically get reindented. You | |
640 | will need to execute one of the following commands to see the effects | |
641 | of your changes. | |
642 | ||
643 | @cindex GNU indent program | |
644 | Also, variables like @code{c-hanging-*} and @code{c-cleanup-list} | |
645 | (@pxref{Custom Auto-newlines}) only affect how on-the-fly code is | |
646 | formatted. Changing the ``hanginess'' of a brace and then | |
647 | reindenting, will not move the brace to a different line. For this, | |
648 | you're better off getting an external program like GNU @code{indent}, | |
649 | which will rearrange brace location, amongst other things. | |
650 | ||
651 | Preprocessor directives are handled as syntactic whitespace from other | |
652 | code, i.e. they can be interspersed anywhere without affecting the | |
653 | indentation of the surrounding code, just like comments. | |
654 | ||
655 | The code inside macro definitions is, by default, still analyzed | |
656 | syntactically so that you get relative indentation there just as you'd | |
657 | get if the same code was outside a macro. However, since there is no | |
658 | hint about the syntactic context, i.e. whether the macro expands to an | |
659 | expression, to some statements, or perhaps to whole functions, the | |
660 | syntactic recognition can be wrong. @ccmode{} manages to figure it | |
661 | out correctly most of the time, though. | |
662 | ||
536610a4 AM |
663 | Some macros, when invoked, ''have their own semicolon''. To get the |
664 | next line indented correctly, rather than as a continuation line, | |
665 | @xref{Macros with ;}. | |
666 | ||
4009494e GM |
667 | Reindenting large sections of code can take a long time. When |
668 | @ccmode{} reindents a region of code, it is essentially equivalent to | |
669 | hitting @key{TAB} on every line of the region. | |
670 | ||
671 | These commands indent code: | |
672 | ||
673 | @table @asis | |
674 | @item @kbd{@key{TAB}} (@code{c-indent-command}) | |
675 | @kindex TAB | |
676 | @findex c-indent-command | |
677 | @findex indent-command (c-) | |
678 | This command indents the current line. That is all you need to know | |
679 | about it for normal use. | |
680 | ||
681 | @code{c-indent-command} does different things, depending on the | |
682 | setting of @code{c-syntactic-indentation} (@pxref{Indentation Engine | |
683 | Basics}): | |
684 | ||
685 | @itemize @bullet | |
686 | @item | |
687 | When it's non-@code{nil} (which it normally is), the command indents | |
688 | the line according to its syntactic context. With a prefix argument | |
689 | (@kbd{C-u @key{TAB}}), it will re-indent the entire | |
690 | expression@footnote{this is only useful for a line starting with a | |
691 | comment opener or an opening brace, parenthesis, or string quote.} | |
692 | that begins at the line's left margin. | |
693 | ||
694 | @item | |
695 | When it's @code{nil}, the command indents the line by an extra | |
696 | @code{c-basic-offset} columns. A prefix argument acts as a | |
697 | multiplier. A bare prefix (@kbd{C-u @key{TAB}}) is equivalent to -1, | |
698 | removing @code{c-basic-offset} columns from the indentation. | |
699 | @end itemize | |
700 | ||
701 | The precise behavior is modified by several variables: With | |
702 | @code{c-tab-always-indent}, you can make @key{TAB} insert whitespace | |
703 | in some circumstances---@code{c-insert-tab-function} then defines | |
704 | precisely what sort of ``whitespace'' this will be. Set the standard | |
705 | Emacs variable @code{indent-tabs-mode} to @code{t} if you want real | |
706 | @samp{tab} characters to be used in the indentation, to @code{nil} if | |
707 | you want only spaces. @xref{Just Spaces,,, @emacsman{}, | |
708 | @emacsmantitle{}}. | |
709 | ||
710 | @defopt c-tab-always-indent | |
711 | @vindex tab-always-indent (c-) | |
712 | @cindex literal | |
713 | This variable modifies how @key{TAB} operates. | |
714 | @itemize @bullet | |
715 | @item | |
716 | When it is @code{t} (the default), @key{TAB} simply indents the | |
717 | current line. | |
718 | @item | |
719 | When it is @code{nil}, @key{TAB} (re)indents the line only if point is | |
720 | to the left of the first non-whitespace character on the line. | |
721 | Otherwise it inserts some whitespace (a tab or an equivalent number of | |
722 | spaces - see below) at point. | |
723 | @item | |
724 | With some other value, the line is reindented. Additionally, if point | |
725 | is within a string or comment, some whitespace is inserted. | |
726 | @end itemize | |
727 | @end defopt | |
728 | ||
729 | @defopt c-insert-tab-function | |
730 | @vindex insert-tab-function (c-) | |
731 | @findex tab-to-tab-stop | |
732 | When ``some whitespace'' is inserted as described above, what actually | |
733 | happens is that the function stored in @code{c-insert-tab-function} is | |
734 | called. Normally, this is @code{insert-tab}, which inserts a real tab | |
735 | character or the equivalent number of spaces (depending on | |
736 | @code{indent-tabs-mode}). Some people, however, set | |
737 | @code{c-insert-tab-function} to @code{tab-to-tab-stop} so as to get | |
738 | hard tab stops when indenting. | |
739 | @end defopt | |
740 | @end table | |
741 | ||
742 | @noindent | |
743 | The kind of indentation the next five commands do depends on the | |
744 | setting of @code{c-syntactic-indentation} (@pxref{Indentation Engine | |
745 | Basics}): | |
746 | @itemize @bullet | |
747 | @item | |
748 | when it is non-@code{nil} (the default), the commands indent lines | |
749 | according to their syntactic context; | |
750 | @item | |
751 | when it is @code{nil}, they just indent each line the same amount as | |
752 | the previous non-blank line. The commands that indent a region aren't | |
753 | very useful in this case. | |
754 | @end itemize | |
755 | ||
756 | @table @asis | |
757 | @item @kbd{C-j} (@code{newline-and-indent}) | |
758 | @kindex C-j | |
759 | @findex newline-and-indent | |
760 | Inserts a newline and indents the new blank line, ready to start | |
761 | typing. This is a standard (X)Emacs command. | |
762 | ||
763 | @item @kbd{C-M-q} (@code{c-indent-exp}) | |
764 | @kindex C-M-q | |
765 | @findex c-indent-exp | |
766 | @findex indent-exp (c-) | |
767 | Indents an entire balanced brace or parenthesis expression. Note that | |
768 | point must be on the opening brace or parenthesis of the expression | |
769 | you want to indent. | |
770 | ||
771 | @item @kbd{C-c C-q} (@code{c-indent-defun}) | |
772 | @kindex C-c C-q | |
773 | @findex c-indent-defun | |
774 | @findex indent-defun (c-) | |
775 | Indents the entire top-level function, class or macro definition | |
776 | encompassing point. It leaves point unchanged. This function can't be | |
777 | used to reindent a nested brace construct, such as a nested class or | |
778 | function, or a Java method. The top-level construct being reindented | |
779 | must be complete, i.e. it must have both a beginning brace and an ending | |
780 | brace. | |
781 | ||
782 | @item @kbd{C-M-\} (@code{indent-region}) | |
783 | @kindex C-M-\ | |
784 | @findex indent-region | |
785 | Indents an arbitrary region of code. This is a standard Emacs command, | |
786 | tailored for C code in a @ccmode{} buffer. Note, of course, that point | |
787 | and mark must delineate the region you want to indent. | |
788 | ||
789 | @item @kbd{C-M-h} (@code{c-mark-function}) | |
790 | @kindex C-M-h | |
791 | @findex c-mark-function | |
792 | @findex mark-function (c-) | |
793 | While not strictly an indentation command, this is useful for marking | |
794 | the current top-level function or class definition as the current | |
795 | region. As with @code{c-indent-defun}, this command operates on | |
796 | top-level constructs, and can't be used to mark say, a Java method. | |
797 | @end table | |
798 | ||
799 | These variables are also useful when indenting code: | |
800 | ||
801 | @defopt indent-tabs-mode | |
802 | This is a standard Emacs variable that controls how line indentation | |
803 | is composed. When it's non-@code{nil}, tabs can be used in a line's | |
804 | indentation, otherwise only spaces are used. | |
805 | @end defopt | |
806 | ||
807 | @defopt c-progress-interval | |
808 | @vindex progress-interval (c-) | |
809 | When indenting large regions of code, this variable controls how often a | |
810 | progress message is displayed. Set this variable to @code{nil} to | |
811 | inhibit the progress messages, or set it to an integer which is how | |
812 | often (in seconds) progress messages are to be displayed. | |
813 | @end defopt | |
814 | ||
815 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
816 | @node Comment Commands, Movement Commands, Indentation Commands, Commands | |
817 | @comment node-name, next, previous, up | |
818 | @section Comment Commands | |
819 | @cindex comments (insertion of) | |
820 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
821 | ||
822 | @table @asis | |
823 | @item @kbd{C-c C-c} (@code{comment-region}) | |
824 | @kindex C-c C-c | |
825 | @findex comment-region | |
826 | This command comments out the lines that start in the region. With a | |
827 | negative argument, it does the opposite - it deletes the comment | |
828 | delimiters from these lines. @xref{Multi-Line Comments,,, emacs, GNU | |
829 | Emacs Manual}, for fuller details. @code{comment-region} isn't | |
830 | actually part of @ccmode{} - it is given a @ccmode{} binding for | |
831 | convenience. | |
832 | ||
833 | @item @kbd{M-;} (@code{comment-dwim} or @code{indent-for-comment} @footnote{The name of this command varies between (X)Emacs versions.}) | |
834 | @kindex M-; | |
835 | @findex comment-dwim | |
836 | @findex indent-for-comment | |
837 | Insert a comment at the end of the current line, if none is there | |
838 | already. Then reindent the comment according to @code{comment-column} | |
839 | @ifclear XEMACS | |
840 | (@pxref{Options for Comments,,, emacs, GNU Emacs Manual}) | |
841 | @end ifclear | |
842 | @ifset XEMACS | |
843 | (@pxref{Comments,,, xemacs, XEmacs User's Manual}) | |
844 | @end ifset | |
845 | and the variables below. Finally, position the point after the | |
846 | comment starter. @kbd{C-u M-;} kills any comment on the current line, | |
847 | together with any whitespace before it. This is a standard Emacs | |
848 | command, but @ccmode{} enhances it a bit with two variables: | |
849 | ||
850 | @defopt c-indent-comment-alist | |
851 | @vindex indent-comment-alist (c-) | |
852 | @vindex comment-column | |
853 | This style variable allows you to vary the column that @kbd{M-;} puts | |
854 | the comment at, depending on what sort of code is on the line, and | |
855 | possibly the indentation of any similar comment on the preceding line. | |
856 | It is an association list that maps different types of lines to | |
857 | actions describing how they should be handled. If a certain line type | |
858 | isn't present on the list then the line is indented to the column | |
859 | specified by @code{comment-column}. | |
860 | ||
861 | See the documentation string for a full description of this | |
862 | variable (use @kbd{C-h v c-indent-comment-alist}). | |
863 | @end defopt | |
864 | ||
865 | @defopt c-indent-comments-syntactically-p | |
866 | @vindex indent-comments-syntactically-p (c-) | |
867 | Normally, when this style variable is @code{nil}, @kbd{M-;} will | |
868 | indent comment-only lines according to @code{c-indent-comment-alist}, | |
869 | just as it does with lines where other code precede the comments. | |
870 | However, if you want it to act just like @key{TAB} for comment-only | |
871 | lines you can get that by setting | |
872 | @code{c-indent-comments-syntactically-p} to non-@code{nil}. | |
873 | ||
874 | If @code{c-indent-comments-syntactically-p} is non-@code{nil} then | |
875 | @code{c-indent-comment-alist} won't be consulted at all for comment-only | |
876 | lines. | |
877 | @end defopt | |
878 | @end table | |
879 | ||
880 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
881 | @node Movement Commands, Filling and Breaking, Comment Commands, Commands | |
882 | @comment node-name, next, previous, up | |
883 | @section Movement Commands | |
884 | @cindex movement | |
885 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
886 | ||
887 | @ccmode{} contains some useful commands for moving around in C code. | |
888 | ||
889 | @table @asis | |
890 | @item @kbd{C-M-a} (@code{c-beginning-of-defun}) | |
891 | @itemx @kbd{C-M-e} (@code{c-end-of-defun}) | |
892 | @findex c-beginning-of-defun | |
893 | @findex c-end-of-defun | |
020716e1 AM |
894 | @vindex c-defun-tactic |
895 | @vindex defun-tactic (c-) | |
4009494e GM |
896 | |
897 | Move to the beginning or end of the current or next function. Other | |
898 | constructs (such as a structs or classes) which have a brace block | |
899 | also count as ``functions'' here. To move over several functions, you | |
900 | can give these commands a repeat count. | |
901 | ||
902 | The start of a function is at its header. The end of the function is | |
903 | after its closing brace, or after the semicolon of a construct (such | |
904 | as a @code{struct}) which doesn't end at the brace. These two | |
905 | commands try to leave point at the beginning of a line near the actual | |
906 | start or end of the function. This occasionally causes point not to | |
907 | move at all. | |
908 | ||
020716e1 AM |
909 | By default, these commands will recognize functions contained within a |
910 | @dfn{declaration scope} such as a C++ @code{class} or @code{namespace} | |
911 | construct, should the point start inside it. If @ccmode fails to find | |
912 | function beginnings or ends inside the current declaration scope, it | |
913 | will search the enclosing scopes. If you want @ccmode to recognize | |
914 | functions only at the top level@footnote{this was @ccmode{}'s | |
40ba43b4 | 915 | behavior prior to version 5.32.}, set @code{c-defun-tactic} to |
020716e1 AM |
916 | @code{t}. |
917 | ||
4009494e GM |
918 | These functions are analogous to the Emacs built-in commands |
919 | @code{beginning-of-defun} and @code{end-of-defun}, except they | |
920 | eliminate the constraint that the top-level opening brace of the defun | |
921 | must be in column zero. See @ref{Defuns,,,@emacsman{}, | |
922 | @emacsmantitle{}}, for more information. | |
923 | ||
924 | @item @kbd{C-M-a} (AWK Mode) (@code{c-awk-beginning-of-defun}) | |
925 | @itemx @kbd{C-M-e} (AWK Mode) (@code{c-awk-end-of-defun}) | |
926 | @kindex C-M-a (AWK Mode) | |
927 | @kindex C-M-e (AWK Mode) | |
928 | @findex c-awk-beginning-of-defun | |
929 | @findex awk-beginning-of-defun (c-) | |
930 | @findex c-awk-end-of-defun | |
931 | @findex awk-end-of-defun (c-) | |
932 | Move to the beginning or end of the current or next AWK defun. These | |
933 | commands can take prefix-arguments, their functionality being entirely | |
934 | equivalent to @code{beginning-of-defun} and @code{end-of-defun}. | |
935 | ||
936 | AWK Mode @dfn{defuns} are either pattern/action pairs (either of which | |
937 | might be implicit) or user defined functions. Having the @samp{@{} and | |
938 | @samp{@}} (if there are any) in column zero, as is suggested for some | |
939 | modes, is neither necessary nor helpful in AWK mode. | |
940 | ||
941 | @item @kbd{M-a} (@code{c-beginning-of-statement}) | |
942 | @itemx @kbd{M-e} (@code{c-end-of-statement}) | |
943 | @kindex M-a | |
944 | @kindex M-e | |
945 | @findex c-beginning-of-statement | |
946 | @findex c-end-of-statement | |
947 | @findex beginning-of-statement (c-) | |
948 | @findex end-of-statement (c-) | |
949 | Move to the beginning or end of the innermost C statement. If point | |
950 | is already there, move to the next beginning or end of a statement, | |
951 | even if that means moving into a block. (Use @kbd{C-M-b} or | |
952 | @kbd{C-M-f} to move over a balanced block.) A prefix argument @var{n} | |
953 | means move over @var{n} statements. | |
954 | ||
955 | If point is within or next to a comment or a string which spans more | |
956 | than one line, these commands move by sentences instead of statements. | |
957 | ||
958 | When called from a program, these functions take three optional | |
959 | arguments: the repetition count, a buffer position limit which is the | |
960 | farthest back to search for the syntactic context, and a flag saying | |
961 | whether to do sentence motion in or near comments and multiline | |
962 | strings. | |
963 | ||
964 | @item @kbd{C-c C-u} (@code{c-up-conditional}) | |
965 | @kindex C-c C-u | |
966 | @findex c-up-conditional | |
967 | @findex up-conditional (c-) | |
968 | Move back to the containing preprocessor conditional, leaving the mark | |
969 | behind. A prefix argument acts as a repeat count. With a negative | |
970 | argument, move forward to the end of the containing preprocessor | |
971 | conditional. | |
972 | ||
973 | @samp{#elif} is treated like @samp{#else} followed by @samp{#if}, so the | |
974 | function stops at them when going backward, but not when going | |
975 | forward. | |
976 | ||
977 | This key sequence is not bound in AWK Mode, which doesn't have | |
978 | preprocessor statements. | |
979 | ||
980 | @item @kbd{M-x c-up-conditional-with-else} | |
981 | @findex c-up-conditional-with-else | |
982 | @findex up-conditional-with-else (c-) | |
983 | A variety of @code{c-up-conditional} that also stops at @samp{#else} | |
984 | lines. Normally those lines are ignored. | |
985 | ||
986 | @item @kbd{M-x c-down-conditional} | |
987 | @findex c-down-conditional | |
988 | @findex down-conditional (c-) | |
989 | Move forward into the next nested preprocessor conditional, leaving | |
990 | the mark behind. A prefix argument acts as a repeat count. With a | |
991 | negative argument, move backward into the previous nested preprocessor | |
992 | conditional. | |
993 | ||
994 | @samp{#elif} is treated like @samp{#else} followed by @samp{#if}, so the | |
995 | function stops at them when going forward, but not when going backward. | |
996 | ||
997 | @item @kbd{M-x c-down-conditional-with-else} | |
998 | @findex c-down-conditional-with-else | |
999 | @findex down-conditional-with-else (c-) | |
1000 | A variety of @code{c-down-conditional} that also stops at @samp{#else} | |
1001 | lines. Normally those lines are ignored. | |
1002 | ||
1003 | @item @kbd{C-c C-p} (@code{c-backward-conditional}) | |
1004 | @itemx @kbd{C-c C-n} (@code{c-forward-conditional}) | |
1005 | @kindex C-c C-p | |
1006 | @kindex C-c C-n | |
1007 | @findex c-backward-conditional | |
1008 | @findex c-forward-conditional | |
1009 | @findex backward-conditional (c-) | |
1010 | @findex forward-conditional (c-) | |
1011 | Move backward or forward across a preprocessor conditional, leaving | |
1012 | the mark behind. A prefix argument acts as a repeat count. With a | |
1013 | negative argument, move in the opposite direction. | |
1014 | ||
1015 | These key sequences are not bound in AWK Mode, which doesn't have | |
1016 | preprocessor statements. | |
1017 | ||
1018 | @item @kbd{M-x c-backward-into-nomenclature} | |
1019 | @itemx @kbd{M-x c-forward-into-nomenclature} | |
1020 | @findex c-backward-into-nomenclature | |
1021 | @findex c-forward-into-nomenclature | |
1022 | @findex backward-into-nomenclature (c-) | |
1023 | @findex forward-into-nomenclature (c-) | |
1024 | A popular programming style, especially for object-oriented languages | |
1025 | such as C++ is to write symbols in a mixed case format, where the | |
1026 | first letter of each word is capitalized, and not separated by | |
1027 | underscores. E.g. @samp{SymbolsWithMixedCaseAndNoUnderlines}. | |
1028 | ||
1029 | These commands move backward or forward to the beginning of the next | |
1030 | capitalized word. With prefix argument @var{n}, move @var{n} times. | |
1031 | If @var{n} is negative, move in the opposite direction. | |
1032 | ||
1033 | Note that these two commands have been superseded by | |
aaef4f91 | 1034 | @code{subword-mode}, which you should use instead. @xref{Subword |
4009494e GM |
1035 | Movement}. They might be removed from a future release of @ccmode{}. |
1036 | @end table | |
1037 | ||
1038 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1039 | @node Filling and Breaking, Minor Modes, Movement Commands, Commands | |
1040 | @comment node-name, next, previous, up | |
1041 | @section Filling and Line Breaking Commands | |
1042 | @cindex text filling | |
1043 | @cindex line breaking | |
1044 | @cindex comment handling | |
1045 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1046 | ||
1047 | Since there's a lot of normal text in comments and string literals, | |
1048 | @ccmode{} provides features to edit these like in text mode. The goal | |
1049 | is to do it seamlessly, i.e. you can use auto fill mode, sentence and | |
1050 | paragraph movement, paragraph filling, adaptive filling etc. wherever | |
1051 | there's a piece of normal text without having to think much about it. | |
1052 | @ccmode{} keeps the indentation, fixes suitable comment line prefixes, | |
1053 | and so on. | |
1054 | ||
1055 | You can configure the exact way comments get filled and broken, and | |
1056 | where Emacs does auto-filling (see @pxref{Custom Filling and | |
1057 | Breaking}). Typically, the style system (@pxref{Styles}) will have | |
1058 | set this up for you, so you probably won't have to bother. | |
1059 | ||
1060 | @findex auto-fill-mode | |
1061 | @cindex Auto Fill mode | |
1062 | @cindex paragraph filling | |
1063 | Line breaks are by default handled (almost) the same regardless of | |
1064 | whether they are made by auto fill mode (@pxref{Auto Fill,,, | |
1065 | @emacsman{}, @emacsmantitle{}}), by paragraph filling (e.g. with | |
1066 | @kbd{M-q}), or explicitly with @kbd{M-j} or similar methods. In | |
1067 | string literals, the new line gets the same indentation as the | |
1068 | previous nonempty line.@footnote{You can change this default by | |
1069 | setting the @code{string} syntactic symbol (@pxref{Syntactic Symbols} | |
1070 | and @pxref{Customizing Indentation})}. | |
1071 | ||
1072 | @table @asis | |
1073 | @item @kbd{M-q} (@code{c-fill-paragraph}) | |
1074 | @kindex M-q | |
1075 | @findex c-fill-paragraph | |
1076 | @findex fill-paragraph (c-) | |
1077 | @cindex Javadoc markup | |
1078 | @cindex Pike autodoc markup | |
1079 | This command fills multiline string literals and both block | |
1080 | and line style comments. In Java buffers, the Javadoc markup words | |
1081 | are recognized as paragraph starters. The line oriented Pike autodoc | |
1082 | markup words are recognized in the same way in Pike mode. | |
1083 | ||
1084 | The formatting of the starters (@code{/*}) and enders (@code{*/}) of | |
1085 | block comments are kept as they were before the filling. I.e., if | |
1086 | either the starter or ender were on a line of its own, then it stays | |
1087 | on its own line; conversely, if the delimiter has comment text on its | |
1088 | line, it keeps at least one word of that text with it on the line. | |
1089 | ||
1090 | This command is the replacement for @code{fill-paragraph} in @ccmode{} | |
1091 | buffers. | |
1092 | ||
1093 | @item @kbd{M-j} (@code{c-indent-new-comment-line}) | |
1094 | @kindex M-j | |
1095 | @findex c-indent-new-comment-line | |
1096 | @findex indent-new-comment-line (c-) | |
1097 | This breaks the current line at point and indents the new line. If | |
1098 | point was in a comment, the new line gets the proper comment line | |
1099 | prefix. If point was inside a macro, a backslash is inserted before | |
1100 | the line break. It is the replacement for | |
1101 | @code{indent-new-comment-line}. | |
1102 | ||
1103 | @item @kbd{M-x c-context-line-break} | |
1104 | @findex c-context-line-break | |
1105 | @findex context-line-break (c-) | |
1106 | Insert a line break suitable to the context: If the point is inside a | |
1107 | comment, the new line gets the suitable indentation and comment line | |
1108 | prefix like @code{c-indent-new-comment-line}. In normal code it's | |
1109 | indented like @code{newline-and-indent} would do. In macros it acts | |
1110 | like @code{newline-and-indent} but additionally inserts and optionally | |
1111 | aligns the line ending backslash so that the macro remains unbroken. | |
1112 | @xref{Custom Macros}, for details about the backslash alignment. In a | |
1113 | string, a backslash is inserted only if the string is within a | |
1114 | macro@footnote{In GCC, unescaped line breaks within strings are | |
1115 | valid.}. | |
1116 | ||
1117 | This function is not bound to a key by default, but it's intended to be | |
1118 | used on the @kbd{RET} key. If you like the behavior of | |
1119 | @code{newline-and-indent} on @kbd{RET}, you should consider switching to | |
1120 | this function. @xref{Sample .emacs File}. | |
1121 | ||
1122 | @item @kbd{M-x c-context-open-line} | |
1123 | @findex c-context-open-line | |
1124 | @findex context-open-line (c-) | |
1125 | This is to @kbd{C-o} (@kbd{M-x open-line}) as | |
1126 | @code{c-context-line-break} is to @kbd{RET}. I.e. it works just like | |
1127 | @code{c-context-line-break} but leaves the point before the inserted | |
1128 | line break. | |
1129 | @end table | |
1130 | ||
1131 | ||
1132 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1133 | @node Minor Modes, Electric Keys, Filling and Breaking, Commands | |
1134 | @comment node-name, next, previous, up | |
1135 | @section Minor Modes | |
1136 | @cindex Minor Modes | |
1137 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1138 | ||
1139 | @ccmode{} contains several minor-mode-like features that you might | |
1140 | find useful while writing new code or editing old code: | |
1141 | ||
1142 | @table @asis | |
1143 | @item electric mode | |
1144 | When this is enabled, certain visible characters cause reformatting as | |
1145 | they are typed. This is normally helpful, but can be a nuisance when | |
1146 | editing chaotically formatted code. It can also be disconcerting, | |
1147 | especially for users who are new to @ccmode{}. | |
1148 | @item auto-newline mode | |
1149 | This automatically inserts newlines where you'd probably want to type | |
1150 | them yourself, e.g. after typing @samp{@}}s. Its action is suppressed | |
1151 | when electric mode is disabled. | |
1152 | @item hungry-delete mode | |
1153 | This lets you delete a contiguous block of whitespace with a single | |
1154 | key - for example, the newline and indentation just inserted by | |
1155 | auto-newline when you want to back up and write a comment after the | |
1156 | last statement. | |
1157 | @item subword mode | |
1158 | This mode makes basic word movement commands like @kbd{M-f} | |
1159 | (@code{forward-word}) and @kbd{M-b} (@code{backward-word}) treat the | |
1160 | parts of sillycapsed symbols as different words. | |
1161 | E.g. @samp{NSGraphicsContext} is treated as three words @samp{NS}, | |
1162 | @samp{Graphics}, and @samp{Context}. | |
1163 | @item syntactic-indentation mode | |
1164 | When this is enabled (which it normally is), indentation commands such | |
1165 | as @kbd{C-j} indent lines of code according to their syntactic | |
1166 | structure. Otherwise, a line is simply indented to the same level as | |
1167 | the previous one and @kbd{@key{TAB}} adjusts the indentation in steps | |
1168 | of `c-basic-offset'. | |
1169 | @end table | |
1170 | ||
1171 | Full details on how these minor modes work are at @ref{Electric Keys}, | |
1172 | @ref{Auto-newlines}, @ref{Hungry WS Deletion}, @ref{Subword Movement}, | |
1173 | and @ref{Indentation Engine Basics}. | |
1174 | ||
1175 | You can toggle each of these minor modes on and off, and you can | |
c5e87d10 | 1176 | configure @ccmode{} so that it starts up with your favorite |
4009494e GM |
1177 | combination of them (@pxref{Sample .emacs File}). By default, when |
1178 | you initialize a buffer, electric mode and syntactic-indentation mode | |
1179 | are enabled but the other two modes are disabled. | |
1180 | ||
1181 | @ccmode{} displays the current state of the first four of these minor | |
1182 | modes on the modeline by appending letters to the major mode's name, | |
1183 | one letter for each enabled minor mode - @samp{l} for electric mode, | |
1184 | @samp{a} for auto-newline mode, @samp{h} for hungry delete mode, and | |
1185 | @samp{w} for subword mode. If all these modes were enabled, you'd see | |
1186 | @samp{C/lahw}@footnote{The @samp{C} would be replaced with the name of | |
1187 | the language in question for the other languages @ccmode{} supports.}. | |
1188 | ||
1189 | Here are the commands to toggle these modes: | |
1190 | ||
1191 | @table @asis | |
1192 | @item @kbd{C-c C-l} (@code{c-toggle-electric-state}) | |
1193 | @kindex C-c C-l | |
1194 | @findex c-toggle-electric-state | |
1195 | @findex toggle-electric-state (c-) | |
1196 | Toggle electric minor mode. When the command turns the mode off, it | |
1197 | also suppresses auto-newline mode. | |
1198 | ||
1199 | @item @kbd{C-c C-a} (@code{c-toggle-auto-newline}) | |
1200 | @kindex C-c C-a | |
1201 | @findex c-toggle-auto-newline | |
1202 | @findex toggle-auto-newline (c-) | |
1203 | Toggle auto-newline minor mode. When the command turns the mode on, | |
1204 | it also enables electric minor mode. | |
1205 | ||
1206 | @item @kbd{M-x c-toggle-hungry-state}@footnote{Prior to @ccmode{} 5.31, this command was bound to @kbd{C-c C-d}.} | |
1207 | @findex c-toggle-hungry-state | |
1208 | @findex toggle-hungry-state (c-) | |
1209 | Toggle hungry-delete minor mode. | |
1210 | ||
1211 | @item @kbd{M-x c-toggle-auto-hungry-state}@footnote{Prior to @ccmode{} 5.31, this command was bound to @kbd{C-c C-t}.} | |
1212 | @findex c-toggle-auto-hungry-state | |
1213 | @findex toggle-auto-hungry-state (c-) | |
1214 | Toggle both auto-newline and hungry delete minor modes. | |
1215 | ||
aaef4f91 | 1216 | @item @kbd{C-c C-w} (@code{M-x subword-mode}) |
4009494e | 1217 | @kindex C-c C-w |
aaef4f91 | 1218 | @findex subword-mode |
4009494e GM |
1219 | Toggle subword mode. |
1220 | ||
1221 | @item @kbd{M-x c-toggle-syntactic-indentation} | |
1222 | @findex c-toggle-syntactic-indentation | |
1223 | @findex toggle-syntactic-indentation (c-) | |
1224 | Toggle syntactic-indentation mode. | |
1225 | @end table | |
1226 | ||
1227 | Common to all the toggle functions above is that if they are called | |
1228 | programmatically, they take an optional numerical argument. A | |
1229 | positive value will turn on the minor mode (or both of them in the | |
1230 | case of @code{c-toggle-auto-hungry-state}) and a negative value will | |
1231 | turn it (or them) off. | |
1232 | ||
1233 | ||
1234 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1235 | @node Electric Keys, Auto-newlines, Minor Modes, Commands | |
1236 | @comment node-name, next, previous, up | |
1237 | @section Electric Keys and Keywords | |
1238 | @cindex electric characters | |
1239 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1240 | ||
1241 | Most punctuation keys provide @dfn{electric} behavior - as well as | |
1242 | inserting themselves they perform some other action, such as | |
1243 | reindenting the line. This reindentation saves you from having to | |
1244 | reindent a line manually after typing, say, a @samp{@}}. A few | |
1245 | keywords, such as @code{else}, also trigger electric action. | |
1246 | ||
a1bf7841 | 1247 | You can inhibit the electric behavior described here by disabling |
4009494e GM |
1248 | electric minor mode (@pxref{Minor Modes}). |
1249 | ||
1250 | Common to all these keys is that they only behave electrically when | |
1251 | used in normal code (as contrasted with getting typed in a string | |
1252 | literal or comment). Those which cause re-indentation do so only when | |
1253 | @code{c-syntactic-indentation} has a non-@code{nil} value (which it | |
1254 | does by default). | |
1255 | ||
1256 | These keys and keywords are: | |
1257 | @c ACM, 2004/8/24: c-electric-pound doesn't check c-s-i: this is more | |
1258 | @c like a bug in the code than a bug in this document. It'll get | |
1259 | @c fixed in the code sometime. | |
1260 | ||
1261 | @table @kbd | |
1262 | @item # | |
1263 | @kindex # | |
1264 | @findex c-electric-pound | |
1265 | @findex electric-pound (c-) | |
1266 | @vindex c-electric-pound-behavior | |
1267 | @vindex electric-pound-behavior (c-) | |
1268 | Pound (bound to @code{c-electric-pound}) is electric when typed as the | |
1269 | first non-whitespace character on a line and not within a macro | |
1270 | definition. In this case, the variable @code{c-electric-pound-behavior} | |
1271 | is consulted for the electric behavior. This variable takes a list | |
1272 | value, although the only element currently defined is @code{alignleft}, | |
1273 | which tells this command to force the @samp{#} character into column | |
1274 | zero. This is useful for entering preprocessor macro definitions. | |
1275 | ||
1276 | Pound is not electric in AWK buffers, where @samp{#} starts a comment, | |
1277 | and is bound to @code{self-insert-command} like any typical printable | |
1278 | character. | |
1279 | @c ACM, 2004/8/24: Change this (and the code) to do AWK comment | |
1280 | @c reindentation. | |
1281 | ||
1282 | @item * | |
1283 | @kindex * | |
1284 | @itemx / | |
1285 | @kindex / | |
1286 | @findex c-electric-star | |
1287 | @findex electric-star (c-) | |
1288 | @findex c-electric-slash | |
1289 | @findex electric-slash (c-) | |
1290 | A star (bound to @code{c-electric-star}) or a slash | |
1291 | (@code{c-electric-slash}) causes reindentation when you type it as the | |
1292 | second component of a C style block comment opener (@samp{/*}) or a | |
1293 | C++ line comment opener (@samp{//}) respectively, but only if the | |
1294 | comment opener is the first thing on the line (i.e. there's only | |
1295 | whitespace before it). | |
1296 | ||
1297 | Additionally, you can configure @ccmode{} so that typing a slash at | |
1298 | the start of a line within a block comment will terminate the | |
1299 | comment. You don't need to have electric minor mode enabled to get | |
a1bf7841 | 1300 | this behavior. @xref{Clean-ups}. |
4009494e GM |
1301 | |
1302 | In AWK mode, @samp{*} and @samp{/} do not delimit comments and are not | |
1303 | electric. | |
1304 | ||
1305 | @item < | |
1306 | @kindex < | |
1307 | @itemx > | |
1308 | @kindex > | |
1309 | @findex c-electric-lt-gt | |
1310 | @findex electric-lt-gt (c-) | |
1311 | A less-than or greater-than sign (bound to @code{c-electric-lt-gt}) is | |
1312 | electric in two circumstances: when it is an angle bracket in a C++ | |
1313 | @samp{template} declaration (and similar constructs in other | |
1314 | languages) and when it is the second of two @kbd{<} or @kbd{>} | |
1315 | characters in a C++ style stream operator. In either case, the line | |
1316 | is reindented. Angle brackets in C @samp{#include} directives are not | |
1317 | electric. | |
1318 | ||
1319 | @item ( | |
1320 | @kindex ( | |
1321 | @itemx ) | |
1322 | @kindex ) | |
1323 | @findex c-electric-paren | |
1324 | @findex electric-paren (c-) | |
1325 | The normal parenthesis characters @samp{(} and @samp{)} (bound to | |
1326 | @code{c-electric-paren}) reindent the current line. This is useful | |
1327 | for getting the closing parenthesis of an argument list aligned | |
1328 | automatically. | |
1329 | ||
1330 | You can also configure @ccmode{} to insert a space automatically | |
1331 | between a function name and the @samp{(} you've just typed, and to | |
1332 | remove it automatically after typing @samp{)}, should the argument | |
1333 | list be empty. You don't need to have electric minor mode enabled to | |
1334 | get these actions. @xref{Clean-ups}. | |
1335 | ||
1336 | @item @{ | |
1337 | @kindex @{ | |
1338 | @itemx @} | |
1339 | @kindex @} | |
1340 | @findex c-electric-brace | |
1341 | @findex electric-brace (c-) | |
1342 | Typing a brace (bound to @code{c-electric-brace}) reindents the | |
1343 | current line. Also, one or more newlines might be inserted if | |
1344 | auto-newline minor mode is enabled. @xref{Auto-newlines}. | |
1345 | Additionally, you can configure @ccmode{} to compact excess whitespace | |
1346 | inserted by auto-newline mode in certain circumstances. | |
1347 | @xref{Clean-ups}. | |
1348 | ||
1349 | @item : | |
1350 | @kindex : | |
1351 | @findex c-electric-colon | |
1352 | @findex electric-colon (c-) | |
1353 | Typing a colon (bound to @code{c-electric-colon}) reindents the | |
1354 | current line. Additionally, one or more newlines might be inserted if | |
1355 | auto-newline minor mode is enabled. @xref{Auto-newlines}. If you | |
1356 | type a second colon immediately after such an auto-newline, by default | |
1357 | the whitespace between the two colons is removed, leaving a C++ scope | |
1358 | operator. @xref{Clean-ups}. | |
1359 | ||
1360 | If you prefer, you can insert @samp{::} in a single operation, | |
1361 | avoiding all these spurious reindentations, newlines, and clean-ups. | |
1362 | @xref{Other Commands}. | |
1363 | ||
1364 | @item ; | |
1365 | @kindex ; | |
1366 | @itemx , | |
1367 | @kindex , | |
1368 | @findex c-electric-semi&comma | |
1369 | @findex electric-semi&comma (c-) | |
1370 | Typing a semicolon or comma (bound to @code{c-electric-semi&comma}) | |
1371 | reindents the current line. Also, a newline might be inserted if | |
1372 | auto-newline minor mode is enabled. @xref{Auto-newlines}. | |
1373 | Additionally, you can configure @ccmode{} so that when auto-newline | |
1374 | has inserted whitespace after a @samp{@}}, it will be removed again | |
1375 | when you type a semicolon or comma just after it. @xref{Clean-ups}. | |
1376 | ||
1377 | @end table | |
1378 | ||
1379 | @deffn Command c-electric-continued-statement | |
1380 | @findex electric-continued-statement (c-) | |
1381 | ||
1382 | Certain keywords are electric, causing reindentation when they are | |
1383 | preceded only by whitespace on the line. The keywords are those that | |
1384 | continue an earlier statement instead of starting a new one: | |
1385 | @code{else}, @code{while}, @code{catch} (only in C++ and Java) and | |
1386 | @code{finally} (only in Java). | |
1387 | ||
1388 | An example: | |
1389 | ||
1390 | @example | |
1391 | @group | |
1392 | for (i = 0; i < 17; i++) | |
1393 | if (a[i]) | |
1394 | res += a[i]->offset; | |
1395 | else | |
1396 | @end group | |
1397 | @end example | |
1398 | ||
1399 | Here, the @code{else} should be indented like the preceding @code{if}, | |
1400 | since it continues that statement. @ccmode{} will automatically | |
1401 | reindent it after the @code{else} has been typed in full, since only | |
1402 | then is it possible to decide whether it's a new statement or a | |
1403 | continuation of the preceding @code{if}. | |
1404 | ||
1405 | @vindex abbrev-mode | |
1406 | @findex abbrev-mode | |
1407 | @cindex Abbrev mode | |
1408 | @ccmode{} uses Abbrev mode (@pxref{Abbrevs,,, @emacsman{}, @emacsmantitle{}}) | |
1409 | to accomplish this. It's therefore turned on by default in all language | |
1410 | modes except IDL mode, since CORBA IDL doesn't have any statements. | |
1411 | @end deffn | |
1412 | ||
1413 | ||
1414 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1415 | @node Auto-newlines, Hungry WS Deletion, Electric Keys, Commands | |
1416 | @comment node-name, next, previous, up | |
1417 | @section Auto-newline Insertion | |
1418 | @cindex auto-newline | |
1419 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1420 | ||
1421 | When you have @dfn{Auto-newline minor mode} enabled (@pxref{Minor | |
1422 | Modes}), @ccmode{} inserts newlines for you automatically (in certain | |
1423 | syntactic contexts) when you type a left or right brace, a colon, a | |
1424 | semicolon, or a comma. Sometimes a newline appears before the | |
1425 | character you type, sometimes after it, sometimes both. | |
1426 | ||
1427 | Auto-newline only triggers when the following conditions hold: | |
1428 | ||
1429 | @itemize @bullet | |
1430 | @item | |
1431 | Auto-newline minor mode is enabled, as evidenced by the indicator | |
1432 | @samp{a} after the mode name on the modeline (e.g. @samp{C/a} or | |
1433 | @samp{C/la}). | |
1434 | ||
1435 | @item | |
1436 | The character was typed at the end of a line, or with only whitespace | |
1437 | after it, and possibly a @samp{\} escaping the newline. | |
1438 | ||
1439 | @item | |
1440 | The character is not on its own line already. (This applies only to | |
1441 | insertion of a newline @emph{before} the character.) | |
1442 | ||
1443 | @item | |
1444 | @cindex literal | |
1445 | @cindex syntactic whitespace | |
1446 | The character was not typed inside of a literal @footnote{A | |
1447 | @dfn{literal} is defined as any comment, string, or preprocessor macro | |
1448 | definition. These constructs are also known as @dfn{syntactic | |
1449 | whitespace} since they are usually ignored when scanning C code.}. | |
1450 | ||
1451 | @item | |
1452 | No numeric argument was supplied to the command (i.e. it was typed as | |
1453 | normal, with no @kbd{C-u} prefix). | |
1454 | @end itemize | |
1455 | ||
1456 | You can configure the precise circumstances in which newlines get | |
1457 | inserted (see @pxref{Custom Auto-newlines}). Typically, the style | |
1458 | system (@pxref{Styles}) will have set this up for you, so you probably | |
1459 | won't have to bother. | |
1460 | ||
1461 | Sometimes @ccmode{} inserts an auto-newline where you don't want one, | |
1462 | such as after a @samp{@}} when you're about to type a @samp{;}. | |
1463 | Hungry deletion can help here (@pxref{Hungry WS Deletion}), or you can | |
1464 | activate an appropriate @dfn{clean-up}, which will remove the excess | |
1465 | whitespace after you've typed the @samp{;}. See @ref{Clean-ups} for a | |
1466 | full description. See also @ref{Electric Keys} for a summary of | |
1467 | clean-ups listed by key. | |
1468 | ||
1469 | ||
1470 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1471 | @node Hungry WS Deletion, Subword Movement, Auto-newlines, Commands | |
1472 | @comment node-name, next, previous, up | |
1473 | @section Hungry Deletion of Whitespace | |
1474 | @cindex hungry-deletion | |
1475 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1476 | ||
1477 | If you want to delete an entire block of whitespace at point, you can | |
1478 | use @dfn{hungry deletion}. This deletes all the contiguous whitespace | |
1479 | either before point or after point in a single operation. | |
1480 | ``Whitespace'' here includes tabs and newlines, but not comments or | |
1481 | preprocessor commands. Hungry deletion can markedly cut down on the | |
1482 | number of times you have to hit deletion keys when, for example, | |
1483 | you've made a mistake on the preceding line and have already pressed | |
1484 | @kbd{C-j}. | |
1485 | ||
1486 | Hungry deletion is a simple feature that some people find extremely | |
1487 | useful. In fact, you might find yourself wanting it in @strong{all} | |
1488 | your editing modes! | |
1489 | ||
1490 | Loosely speaking, in what follows, @dfn{@key{DEL}} means ``the | |
1491 | backspace key'' and @dfn{@key{DELETE}} means ``the forward delete | |
1492 | key''. This is discussed in more detail below. | |
1493 | ||
1494 | There are two different ways you can use hungry deletion: | |
1495 | ||
1496 | @table @asis | |
1497 | @item Using @dfn{Hungry Delete Mode} with @kbd{@key{DEL}} and @kbd{C-d} | |
1498 | Here you toggle Hungry Delete minor mode with @kbd{M-x | |
1499 | c-toggle-hungry-state}@footnote{Prior to @ccmode{} 5.31, this command | |
1500 | was bound to @kbd{C-c C-d}. @kbd{C-c C-d} is now the default binding | |
1501 | for @code{c-hungry-delete-forward}.} (@pxref{Minor Modes}.) This | |
1502 | makes @kbd{@key{DEL}} and @kbd{C-d} do backwards and forward hungry | |
1503 | deletion. | |
1504 | ||
1505 | @table @asis | |
1506 | @item @kbd{@key{DEL}} (@code{c-electric-backspace}) | |
1507 | @kindex DEL | |
1508 | @findex c-electric-backspace | |
1509 | @findex electric-backspace (c-) | |
1510 | This command is run by default when you hit the @kbd{DEL} key. When | |
1511 | hungry delete mode is enabled, it deletes any amount of whitespace in | |
1512 | the backwards direction. Otherwise, or when used with a prefix | |
1513 | argument or in a literal (@pxref{Auto-newlines}), the command just | |
1514 | deletes backwards in the usual way. (More precisely, it calls the | |
1515 | function contained in the variable @code{c-backspace-function}, | |
1516 | passing it the prefix argument, if any.) | |
1517 | ||
1518 | @item @code{c-backspace-function} | |
1519 | @vindex c-backspace-function | |
1520 | @vindex backspace-function (c-) | |
1521 | @findex backward-delete-char-untabify | |
1522 | Hook that gets called by @code{c-electric-backspace} when it doesn't | |
1523 | do an ``electric'' deletion of the preceding whitespace. The default | |
1524 | value is @code{backward-delete-char-untabify} | |
1525 | (@pxref{Deletion,,,@lispref{}, @lispreftitle{}}, the function which | |
1526 | deletes a single character. | |
1527 | ||
1528 | @item @kbd{C-d} (@code{c-electric-delete-forward}) | |
1529 | @kindex C-d | |
1530 | @findex c-electric-delete-forward | |
1531 | @findex electric-delete-forward (c-) | |
1532 | This function, which is bound to @kbd{C-d} by default, works just like | |
1533 | @code{c-electric-backspace} but in the forward direction. When it | |
1534 | doesn't do an ``electric'' deletion of the following whitespace, it | |
1535 | just does @code{delete-char}, more or less. (Strictly speaking, it | |
1536 | calls the function in @code{c-delete-function} with the prefix | |
1537 | argument.) | |
1538 | ||
1539 | @item @code{c-delete-function} | |
1540 | @vindex c-delete-function | |
1541 | @vindex delete-function (c-) | |
1542 | @findex delete-char | |
1543 | Hook that gets called by @code{c-electric-delete-forward} when it | |
1544 | doesn't do an ``electric'' deletion of the following whitespace. The | |
1545 | default value is @code{delete-char}. | |
1546 | @end table | |
1547 | ||
1548 | @item Using Distinct Bindings | |
1549 | The other (newer and recommended) way to use hungry deletion is to | |
1550 | perform @code{c-hungry-delete-backwards} and | |
1551 | @code{c-hungry-delete-forward} directly through their key sequences | |
1552 | rather than using the minor mode toggling. | |
1553 | ||
1554 | @table @asis | |
1555 | @item @kbd{C-c C-@key{DEL}}, or @kbd{C-c @key{DEL}} (@code{c-hungry-delete-backwards})@footnote{This command was formerly known as @code{c-hungry-backspace}.} | |
1556 | @kindex C-c C-<backspace> | |
1557 | @kindex C-c <backspace> | |
1558 | @kindex C-c C-DEL | |
1559 | @kindex C-c DEL | |
1560 | @findex c-hungry-delete-backwards | |
1561 | @findex hungry-delete-backwards (c-) | |
1562 | Delete any amount of whitespace in the backwards direction (regardless | |
1563 | whether hungry-delete mode is enabled or not). This command is bound | |
1564 | to both @kbd{C-c C-@key{DEL}} and @kbd{C-c @key{DEL}}, since the more | |
1565 | natural one, @kbd{C-c C-@key{DEL}}, is sometimes difficult to type at | |
1566 | a character terminal. | |
1567 | ||
1568 | @item @kbd{C-c C-d}, @kbd{C-c C-@key{DELETE}}, or @kbd{C-c @key{DELETE}} (@code{c-hungry-delete-forward}) | |
1569 | @kindex C-c C-d | |
1570 | @kindex C-c C-<DELETE> | |
1571 | @kindex C-c <DELETE> | |
1572 | @findex c-hungry-delete-forward | |
1573 | @findex hungry-delete-forward (c-) | |
1574 | Delete any amount of whitespace in the forward direction (regardless | |
1575 | whether hungry-delete mode is enabled or not). This command is bound | |
1576 | to both @kbd{C-c C-@key{DELETE}} and @kbd{C-c @key{DELETE}} for the | |
1577 | same reason as for @key{DEL} above. | |
1578 | @end table | |
1579 | @end table | |
1580 | ||
1581 | @kindex <delete> | |
1582 | @kindex <backspace> | |
1583 | ||
1584 | When we talk about @kbd{@key{DEL}}, and @kbd{@key{DELETE}} above, we | |
1585 | actually do so without connecting them to the physical keys commonly | |
1586 | known as @key{Backspace} and @key{Delete}. The default bindings to | |
1587 | those two keys depends on the flavor of (X)Emacs you are using. | |
1588 | ||
1589 | @findex c-electric-delete | |
1590 | @findex electric-delete (c-) | |
1591 | @findex c-hungry-delete | |
1592 | @findex hungry-delete (c-) | |
1593 | @vindex delete-key-deletes-forward | |
1594 | In XEmacs 20.3 and beyond, the @key{Backspace} key is bound to | |
1595 | @code{c-electric-backspace} and the @key{Delete} key is bound to | |
1596 | @code{c-electric-delete}. You control the direction it deletes in by | |
1597 | setting the variable @code{delete-key-deletes-forward}, a standard | |
1598 | XEmacs variable. | |
1599 | @c This variable is encapsulated by XEmacs's (defsubst delete-forward-p ...). | |
1600 | When this variable is non-@code{nil}, @code{c-electric-delete} will do | |
1601 | forward deletion with @code{c-electric-delete-forward}, otherwise it | |
1602 | does backward deletion with @code{c-electric-backspace}. Similarly, | |
1603 | @kbd{C-c @key{Delete}} and @kbd{C-c C-@key{Delete}} are bound to | |
1604 | @code{c-hungry-delete} which is controlled in the same way by | |
1605 | @code{delete-key-deletes-forward}. | |
1606 | ||
1607 | @findex normal-erase-is-backspace-mode | |
1608 | ||
1609 | Emacs 21 and later automatically binds @key{Backspace} and | |
1610 | @key{Delete} to @kbd{DEL} and @kbd{C-d} according to your environment, | |
1611 | and @ccmode{} extends those bindings to @kbd{C-c C-@key{Backspace}} | |
1612 | etc. If you need to change the bindings through | |
1613 | @code{normal-erase-is-backspace-mode} then @ccmode{} will also adapt | |
1614 | its extended bindings accordingly. | |
1615 | ||
1616 | In earlier (X)Emacs versions, @ccmode{} doesn't bind either | |
1617 | @key{Backspace} or @key{Delete} directly. Only the key codes | |
1618 | @kbd{DEL} and @kbd{C-d} are bound, and it's up to the default bindings | |
1619 | to map the physical keys to them. You might need to modify this | |
1620 | yourself if the defaults are unsuitable. | |
1621 | ||
1622 | Getting your @key{Backspace} and @key{Delete} keys properly set up can | |
1623 | sometimes be tricky. The information in @ref{DEL Does Not | |
1624 | Delete,,,emacs, GNU Emacs Manual}, might be helpful if you're having | |
1625 | trouble with this in GNU Emacs. | |
1626 | ||
1627 | ||
1628 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1629 | @node Subword Movement, Other Commands, Hungry WS Deletion, Commands | |
1630 | @comment node-name, next, previous, up | |
1631 | @section Subword Movement and Editing | |
1632 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1633 | ||
1634 | @cindex nomenclature | |
1635 | @cindex subword | |
1636 | In spite of the GNU Coding Standards, it is popular to name a symbol | |
1637 | by mixing uppercase and lowercase letters, e.g. @samp{GtkWidget}, | |
1638 | @samp{EmacsFrameClass}, or @samp{NSGraphicsContext}. Here we call | |
1639 | these mixed case symbols @dfn{nomenclatures}. Also, each capitalized | |
1640 | (or completely uppercase) part of a nomenclature is called a | |
1641 | @dfn{subword}. Here are some examples: | |
1642 | ||
1643 | @multitable {@samp{NSGraphicsContext}} {@samp{NS}, @samp{Graphics}, and @samp{Context}} | |
1644 | @c This could be converted to @headitem when we require Texinfo 4.7 | |
1645 | @iftex | |
1646 | @item @b{Nomenclature} | |
1647 | @tab @b{Subwords} | |
1648 | @end iftex | |
1649 | @ifnottex | |
1650 | @item Nomenclature | |
1651 | @tab Subwords | |
1652 | @item --------------------------------------------------------- | |
1653 | @end ifnottex | |
1654 | @item @samp{GtkWindow} | |
1655 | @tab @samp{Gtk} and @samp{Window} | |
1656 | @item @samp{EmacsFrameClass} | |
1657 | @tab @samp{Emacs}, @samp{Frame}, and @samp{Class} | |
1658 | @item @samp{NSGraphicsContext} | |
1659 | @tab @samp{NS}, @samp{Graphics}, and @samp{Context} | |
1660 | @end multitable | |
1661 | ||
1662 | The subword minor mode replaces the basic word oriented movement and | |
1663 | editing commands with variants that recognize subwords in a | |
1664 | nomenclature and treat them as separate words: | |
1665 | ||
1666 | @findex c-forward-subword | |
1667 | @findex forward-subword (c-) | |
1668 | @findex c-backward-subword | |
1669 | @findex backward-subword (c-) | |
1670 | @findex c-mark-subword | |
1671 | @findex mark-subword (c-) | |
1672 | @findex c-kill-subword | |
1673 | @findex kill-subword (c-) | |
1674 | @findex c-backward-kill-subword | |
1675 | @findex backward-kill-subword (c-) | |
1676 | @findex c-transpose-subwords | |
1677 | @findex transpose-subwords (c-) | |
1678 | @findex c-capitalize-subword | |
1679 | @findex capitalize-subword (c-) | |
1680 | @findex c-upcase-subword | |
1681 | @findex upcase-subword (c-) | |
1682 | @findex c-downcase-subword | |
1683 | @findex downcase-subword (c-) | |
1684 | @multitable @columnfractions .20 .40 .40 | |
1685 | @c This could be converted to @headitem when we require Texinfo 4.7 | |
1686 | @iftex | |
1687 | @item @b{Key} @tab @b{Word oriented command} @tab @b{Subword oriented command} | |
1688 | @end iftex | |
1689 | @ifnottex | |
1690 | @item Key @tab Word oriented command @tab Subword oriented command | |
1691 | @item ---------------------------------------------------------------------------- | |
1692 | @end ifnottex | |
1693 | @item @kbd{M-f} @tab @code{forward-word} @tab @code{c-forward-subword} | |
1694 | @item @kbd{M-b} @tab @code{backward-word} @tab @code{c-backward-subword} | |
1695 | @item @kbd{M-@@} @tab @code{mark-word} @tab @code{c-mark-subword} | |
1696 | @item @kbd{M-d} @tab @code{kill-word} @tab @code{c-kill-subword} | |
1697 | @item @kbd{M-DEL} @tab @code{backward-kill-word} @tab @code{c-backward-kill-subword} | |
1698 | @item @kbd{M-t} @tab @code{transpose-words} @tab @code{c-transpose-subwords} | |
1699 | @item @kbd{M-c} @tab @code{capitalize-word} @tab @code{c-capitalize-subword} | |
1700 | @item @kbd{M-u} @tab @code{upcase-word} @tab @code{c-upcase-subword} | |
1701 | @item @kbd{M-l} @tab @code{downcase-word} @tab @code{c-downcase-subword} | |
1702 | @end multitable | |
1703 | ||
1704 | Note that if you have changed the key bindings for the word oriented | |
1705 | commands in your @file{.emacs} or a similar place, the keys you have | |
1706 | configured are also used for the corresponding subword oriented | |
1707 | commands. | |
1708 | ||
1709 | Type @kbd{C-c C-w} to toggle subword mode on and off. To make the | |
1710 | mode turn on automatically, put the following code in your | |
1711 | @file{.emacs}: | |
1712 | ||
1713 | @example | |
1714 | (add-hook 'c-mode-common-hook | |
aaef4f91 | 1715 | (lambda () (subword-mode 1))) |
4009494e GM |
1716 | @end example |
1717 | ||
aaef4f91 MH |
1718 | As a bonus, you can also use @code{subword-mode} in non-@ccmode{} |
1719 | buffers by typing @kbd{M-x subword-mode}. | |
4009494e GM |
1720 | |
1721 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1722 | @node Other Commands, , Subword Movement, Commands | |
1723 | @comment node-name, next, previous, up | |
1724 | @section Other Commands | |
1725 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1726 | ||
1727 | Here are the various other commands that didn't fit anywhere else: | |
1728 | ||
1729 | @table @asis | |
1730 | @item @kbd{C-c .} (@code{c-set-style}) | |
1731 | @kindex C-c . | |
1732 | @findex c-set-style | |
1733 | @findex set-style (c-) | |
1734 | Switch to the specified style in the current buffer. Use like this: | |
1735 | ||
1736 | @example | |
1737 | @kbd{C-c . @var{style-name} @key{RET}} | |
1738 | @end example | |
1739 | ||
1740 | You can use the @key{TAB} in the normal way to do completion on the | |
1741 | style name. Note that all style names are case insensitive, even the | |
1742 | ones you define yourself. | |
1743 | ||
1744 | Setting a style in this way does @emph{not} automatically reindent your | |
1745 | file. For commands that you can use to view the effect of your changes, | |
1746 | see @ref{Indentation Commands} and @ref{Filling and Breaking}. | |
1747 | ||
1748 | For details of the @ccmode{} style system, see @ref{Styles}. | |
1749 | @item @kbd{C-c :} (@code{c-scope-operator}) | |
1750 | @kindex C-c : | |
1751 | @findex c-scope-operator | |
1752 | @findex scope-operator (c-) | |
1753 | In C++, it is also sometimes desirable to insert the double-colon scope | |
1754 | operator without performing the electric behavior of colon insertion. | |
1755 | @kbd{C-c :} does just this. | |
1756 | ||
1757 | @item @kbd{C-c C-\} (@code{c-backslash-region}) | |
1758 | @kindex C-c C-\ | |
1759 | @findex c-backslash-region | |
1760 | @findex backslash-region (c-) | |
1761 | This function inserts and aligns or deletes end-of-line backslashes in | |
1762 | the current region. These are typically used in multi-line macros. | |
1763 | ||
1764 | With no prefix argument, it inserts any missing backslashes and aligns | |
1765 | them according to the @code{c-backslash-column} and | |
1766 | @code{c-backslash-max-column} variables. With a prefix argument, it | |
1767 | deletes any backslashes. | |
1768 | ||
1769 | The function does not modify blank lines at the start of the region. If | |
1770 | the region ends at the start of a line, it always deletes the backslash | |
1771 | (if any) at the end of the previous line. | |
1772 | ||
1773 | To customize the precise workings of this command, @ref{Custom Macros}. | |
1774 | @end table | |
1775 | ||
1776 | @noindent | |
1777 | The recommended line breaking function, @code{c-context-line-break} | |
1778 | (@pxref{Filling and Breaking}), is especially nice if you edit | |
1779 | multiline macros frequently. When used inside a macro, it | |
1780 | automatically inserts and adjusts the mandatory backslash at the end | |
1781 | of the line to keep the macro together, and it leaves the point at the | |
1782 | right indentation column for the code. Thus you can write code inside | |
1783 | macros almost exactly as you can elsewhere, without having to bother | |
1784 | with the trailing backslashes. | |
1785 | ||
1786 | @table @asis | |
1787 | @item @kbd{C-c C-e} (@code{c-macro-expand}) | |
1788 | @kindex C-c C-e | |
1789 | @findex c-macro-expand | |
1790 | @findex macro-expand (c-) | |
1791 | This command expands C, C++, Objective C or Pike macros in the region, | |
1792 | using an appropriate external preprocessor program. Normally it | |
1793 | displays its output in a temporary buffer, but if you give it a prefix | |
1794 | arg (with @kbd{C-u C-c C-e}) it will overwrite the original region | |
1795 | with the expansion. | |
1796 | ||
1797 | The command does not work in any of the other modes, and the key | |
1798 | sequence is not bound in these other modes. | |
1799 | ||
1800 | @code{c-macro-expand} isn't actually part of @ccmode{}, even though it | |
1801 | is bound to a @ccmode{} key sequence. If you need help setting it up | |
1802 | or have other problems with it, you can either read its source code or | |
1803 | ask for help in the standard (X)Emacs forums. | |
1804 | @end table | |
1805 | ||
1806 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1807 | @node Font Locking, Config Basics, Commands, Top | |
1808 | @comment node-name, next, previous, up | |
1809 | @chapter Font Locking | |
1810 | @cindex font locking | |
1811 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1812 | ||
1813 | @cindex Font Lock mode | |
1814 | ||
1815 | @ccmode{} provides font locking for its supported languages by | |
1816 | supplying patterns for use with Font Lock mode. This means that you | |
1817 | get distinct faces on the various syntactic parts such as comments, | |
1818 | strings, keywords and types, which is very helpful in telling them | |
1819 | apart at a glance and discovering syntactic errors. @xref{Font | |
1820 | Lock,,, emacs, GNU Emacs Manual}, for ways to enable font locking in | |
1821 | @ccmode{} buffers. | |
1822 | ||
1823 | @strong{Please note:} The font locking in AWK mode is currently not | |
1824 | integrated with the rest of @ccmode{}. Only the last section of this | |
1825 | chapter, @ref{AWK Mode Font Locking}, applies to AWK. The other | |
1826 | sections apply to the other languages. | |
1827 | ||
1828 | @menu | |
1829 | * Font Locking Preliminaries:: | |
1830 | * Faces:: | |
1831 | * Doc Comments:: | |
1832 | * AWK Mode Font Locking:: | |
1833 | @end menu | |
1834 | ||
1835 | ||
1836 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1837 | @node Font Locking Preliminaries, Faces, Font Locking, Font Locking | |
1838 | @comment node-name, next, previous, up | |
1839 | @section Font Locking Preliminaries | |
1840 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1841 | ||
1842 | The font locking for most of the @ccmode{} languages were provided | |
1843 | directly by the Font Lock package prior to version 5.30 of @ccmode{}. | |
1844 | In the transition to @ccmode{} the patterns have been reworked | |
1845 | completely and are applied uniformly across all the languages except AWK | |
1846 | mode, just like the indentation rules (although each language still has | |
1847 | some peculiarities of its own, of course). Since the languages | |
1848 | previously had completely separate font locking patterns, this means | |
1849 | that it's a bit different in most languages now. | |
1850 | ||
1851 | The main goal for the font locking in @ccmode{} is accuracy, to provide | |
1852 | a dependable aid in recognizing the various constructs. Some, like | |
1853 | strings and comments, are easy to recognize while others, like | |
1854 | declarations and types, can be very tricky. @ccmode{} can go to great | |
1855 | lengths to recognize declarations and casts correctly, especially when | |
1856 | the types aren't recognized by standard patterns. This is a fairly | |
1857 | demanding analysis which can be slow on older hardware, and it can | |
1858 | therefore be disabled by choosing a lower decoration level with the | |
1859 | variable @code{font-lock-maximum-decoration} (@pxref{Font Lock,,, | |
1860 | emacs, GNU Emacs Manual}). | |
1861 | ||
1862 | @vindex font-lock-maximum-decoration | |
1863 | ||
1864 | The decoration levels are used as follows: | |
1865 | ||
1866 | @enumerate | |
1867 | @comment 1 | |
1868 | @item | |
1869 | Minimal font locking: Fontify only comments, strings and preprocessor | |
1870 | directives (in the languages that use cpp). | |
1871 | ||
1872 | @comment 2 | |
1873 | @item | |
1874 | Fast font locking: In addition to level 1, fontify keywords, simple | |
1875 | types and declarations that are easy to recognize. The variables | |
1876 | @code{*-font-lock-extra-types} (where @samp{*} is the name of the | |
1877 | language) are used to recognize types (see below). Documentation | |
1878 | comments like Javadoc are fontified according to | |
1879 | @code{c-doc-comment-style} (@pxref{Doc Comments}). | |
1880 | ||
1881 | Use this if you think the font locking is too slow. It's the closest | |
1882 | corresponding level to level 3 in the old font lock patterns. | |
1883 | ||
1884 | @comment 3 | |
1885 | @item | |
1886 | Accurate font locking: Like level 2 but uses a different approach that | |
1887 | can recognize types and declarations much more accurately. The | |
1888 | @code{*-font-lock-extra-types} variables are still used, but user | |
1889 | defined types are recognized correctly anyway in most cases. Therefore | |
1890 | those variables should be fairly restrictive and not contain patterns | |
1891 | that are uncertain. | |
1892 | ||
1893 | @cindex Lazy Lock mode | |
1894 | @cindex Just-in-time Lock mode | |
1895 | ||
1896 | This level is designed for fairly modern hardware and a font lock | |
1897 | support mode like Lazy Lock or Just-in-time Lock mode that only | |
1898 | fontifies the parts that are actually shown. Fontifying the whole | |
1899 | buffer at once can easily get bothersomely slow even on contemporary | |
1900 | hardware. @xref{Font Lock,,,@emacsman{}, @emacsmantitle{}}. | |
1901 | @end enumerate | |
1902 | ||
1903 | @cindex user defined types | |
1904 | @cindex types, user defined | |
1905 | ||
1906 | Since user defined types are hard to recognize you can provide | |
1907 | additional regexps to match those you use: | |
1908 | ||
1909 | @defopt c-font-lock-extra-types | |
1910 | @defoptx c++-font-lock-extra-types | |
1911 | @defoptx objc-font-lock-extra-types | |
1912 | @defoptx java-font-lock-extra-types | |
1913 | @defoptx idl-font-lock-extra-types | |
1914 | @defoptx pike-font-lock-extra-types | |
1915 | For each language there's a variable @code{*-font-lock-extra-types}, | |
1916 | where @samp{*} stands for the language in question. It contains a list | |
1917 | of regexps that matches identifiers that should be recognized as types, | |
1918 | e.g. @samp{\\sw+_t} to recognize all identifiers ending with @samp{_t} | |
1919 | as is customary in C code. Each regexp should not match more than a | |
1920 | single identifier. | |
1921 | ||
1922 | The default values contain regexps for many types in standard runtime | |
1923 | libraries that are otherwise difficult to recognize, and patterns for | |
1924 | standard type naming conventions like the @samp{_t} suffix in C and C++. | |
1925 | Java, Objective-C and Pike have as a convention to start class names | |
1926 | with capitals, so there are patterns for that in those languages. | |
1927 | ||
1928 | Despite the names of these variables, they are not only used for | |
1929 | fontification but in other places as well where @ccmode{} needs to | |
1930 | recognize types. | |
1931 | @end defopt | |
1932 | ||
1933 | ||
1934 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1935 | @node Faces, Doc Comments, Font Locking Preliminaries, Font Locking | |
1936 | @comment node-name, next, previous, up | |
1937 | @section Faces | |
1938 | @cindex faces | |
1939 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
1940 | ||
1941 | @ccmode{} attempts to use the standard faces for programming languages | |
1942 | in accordance with their intended purposes as far as possible. No extra | |
1943 | faces are currently provided, with the exception of a replacement face | |
1944 | @code{c-invalid-face} for emacsen that don't provide | |
1945 | @code{font-lock-warning-face}. | |
1946 | ||
1947 | @itemize @bullet | |
1948 | @item | |
1949 | @vindex font-lock-comment-face | |
1950 | Normal comments are fontified in @code{font-lock-comment-face}. | |
1951 | ||
1952 | @item | |
1953 | @vindex font-lock-doc-face | |
1954 | @vindex font-lock-doc-string-face | |
1955 | @vindex font-lock-comment-face | |
1956 | Comments that are recognized as documentation (@pxref{Doc Comments}) | |
1957 | get @code{font-lock-doc-face} (Emacs) or | |
1958 | @code{font-lock-doc-string-face} (XEmacs) if those faces exist. If | |
1959 | they don't then @code{font-lock-comment-face} is used. | |
1960 | ||
1961 | @item | |
1962 | @vindex font-lock-string-face | |
1963 | String and character literals are fontified in | |
1964 | @code{font-lock-string-face}. | |
1965 | ||
1966 | @item | |
1967 | @vindex font-lock-keyword-face | |
1968 | Keywords are fontified with @code{font-lock-keyword-face}. | |
1969 | ||
1970 | @item | |
1971 | @vindex font-lock-function-name-face | |
1972 | @code{font-lock-function-name-face} is used for function names in | |
1973 | declarations and definitions, and classes in those contexts. It's also | |
1974 | used for preprocessor defines with arguments. | |
1975 | ||
1976 | @item | |
1977 | @vindex font-lock-variable-name-face | |
1978 | Variables in declarations and definitions, and other identifiers in such | |
1979 | variable contexts, get @code{font-lock-variable-name-face}. It's also | |
1980 | used for preprocessor defines without arguments. | |
1981 | ||
1982 | @item | |
1983 | @vindex font-lock-constant-face | |
1984 | @vindex font-lock-reference-face | |
1985 | Builtin constants are fontified in @code{font-lock-constant-face} if it | |
1986 | exists, @code{font-lock-reference-face} otherwise. As opposed to the | |
1987 | preceding two faces, this is used on the names in expressions, and it's | |
1988 | not used in declarations, even if there happen to be a @samp{const} in | |
1989 | them somewhere. | |
1990 | ||
1991 | @item | |
1992 | @vindex font-lock-type-face | |
1993 | @code{font-lock-type-face} is put on types (both predefined and user | |
1994 | defined) and classes in type contexts. | |
1995 | ||
1996 | @item | |
1997 | @vindex font-lock-constant-face | |
1998 | @vindex font-lock-reference-face | |
1999 | Label identifiers get @code{font-lock-constant-face} if it exists, | |
2000 | @code{font-lock-reference-face} otherwise. | |
2001 | ||
2002 | @item | |
2003 | Name qualifiers and identifiers for scope constructs are fontified like | |
2004 | labels. | |
2005 | ||
2006 | @item | |
2007 | Special markup inside documentation comments are also fontified like | |
2008 | labels. | |
2009 | ||
2010 | @item | |
2011 | @vindex font-lock-preprocessor-face | |
2012 | @vindex font-lock-builtin-face | |
2013 | @vindex font-lock-reference-face | |
2014 | Preprocessor directives get @code{font-lock-preprocessor-face} if it | |
2015 | exists (i.e. XEmacs). In Emacs they get @code{font-lock-builtin-face} | |
2016 | or @code{font-lock-reference-face}, for lack of a closer equivalent. | |
2017 | ||
2018 | @item | |
2019 | @vindex font-lock-warning-face | |
2020 | @vindex c-invalid-face | |
2021 | @vindex invalid-face (c-) | |
2022 | Some kinds of syntactic errors are fontified with | |
2023 | @code{font-lock-warning-face} in Emacs. In older XEmacs versions | |
2024 | there's no corresponding standard face, so there a special | |
2025 | @code{c-invalid-face} is used, which is defined to stand out sharply by | |
2026 | default. | |
2027 | ||
2028 | Note that it's not used for @samp{#error} or @samp{#warning} directives, | |
2029 | since those aren't syntactic errors in themselves. | |
2030 | @end itemize | |
2031 | ||
2032 | ||
2033 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2034 | @node Doc Comments, AWK Mode Font Locking, Faces, Font Locking | |
2035 | @comment node-name, next, previous, up | |
2036 | @section Documentation Comments | |
2037 | @cindex documentation comments | |
2038 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2039 | ||
2040 | There are various tools to supply documentation in the source as | |
2041 | specially structured comments, e.g. the standard Javadoc tool in Java. | |
2042 | @ccmode{} provides an extensible mechanism to fontify such comments and | |
2043 | the special markup inside them. | |
2044 | ||
2045 | @defopt c-doc-comment-style | |
2046 | @vindex doc-comment-style (c-) | |
2047 | This is a style variable that specifies which documentation comment | |
2048 | style to recognize, e.g. @code{javadoc} for Javadoc comments. | |
2049 | ||
2050 | The value may also be a list of styles, in which case all of them are | |
2051 | recognized simultaneously (presumably with markup cues that don't | |
2052 | conflict). | |
2053 | ||
2054 | The value may also be an association list to specify different comment | |
2055 | styles for different languages. The symbol for the major mode is then | |
2056 | looked up in the alist, and the value of that element is interpreted as | |
2057 | above if found. If it isn't found then the symbol `other' is looked up | |
2058 | and its value is used instead. | |
2059 | ||
2060 | The default value for @code{c-doc-comment-style} is | |
2061 | @w{@code{((java-mode . javadoc) (pike-mode . autodoc) (c-mode . gtkdoc))}}. | |
2062 | ||
2063 | Note that @ccmode{} uses this variable to set other variables that | |
2064 | handle fontification etc. That's done at mode initialization or when | |
2065 | you switch to a style which sets this variable. Thus, if you change it | |
2066 | in some other way, e.g. interactively in a CC Mode buffer, you will need | |
2067 | to do @kbd{M-x java-mode} (or whatever mode you're currently using) to | |
2068 | reinitialize. | |
2069 | ||
2070 | @findex c-setup-doc-comment-style | |
2071 | @findex setup-doc-comment-style (c-) | |
2072 | Note also that when @ccmode{} starts up, the other variables are | |
2073 | modified before the mode hooks are run. If you change this variable in | |
2074 | a mode hook, you'll have to call @code{c-setup-doc-comment-style} | |
2075 | afterwards to redo that work. | |
2076 | @end defopt | |
2077 | ||
2078 | @ccmode{} currently provides handing of the following doc comment | |
2079 | styles: | |
2080 | ||
2081 | @table @code | |
2082 | @item javadoc | |
2083 | @cindex Javadoc markup | |
2084 | Javadoc comments, the standard tool in Java. | |
2085 | ||
2086 | @item autodoc | |
2087 | @cindex Pike autodoc markup | |
2088 | For Pike autodoc markup, the standard in Pike. | |
2089 | ||
2090 | @item gtkdoc | |
2091 | @cindex GtkDoc markup | |
2092 | For GtkDoc markup, widely used in the Gnome community. | |
2093 | @end table | |
2094 | ||
2095 | The above is by no means complete. If you'd like to see support for | |
2096 | other doc comment styles, please let us know (@pxref{Mailing Lists and | |
2097 | Bug Reports}). | |
2098 | ||
2099 | You can also write your own doc comment fontification support to use | |
2100 | with @code{c-doc-comment-style}: Supply a variable or function | |
2101 | @code{*-font-lock-keywords} where @samp{*} is the name you want to use | |
2102 | in @code{c-doc-comment-style}. If it's a variable, it's prepended to | |
2103 | @code{font-lock-keywords}. If it's a function, it's called at mode | |
2104 | initialization and the result is prepended. For an example, see | |
2105 | @code{javadoc-font-lock-keywords} in @file{cc-fonts.el}. | |
2106 | ||
2107 | If you add support for another doc comment style, please consider | |
2108 | contributing it - send a note to @email{bug-cc-mode@@gnu.org}. | |
2109 | ||
2110 | ||
2111 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2112 | @node AWK Mode Font Locking, , Doc Comments, Font Locking | |
2113 | @comment node-name, next, previous, up | |
2114 | @section AWK Mode Font Locking | |
2115 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2116 | ||
2117 | The general appearance of font-locking in AWK mode is much like in any | |
2118 | other programming mode. @xref{Faces For Font Lock,,,elisp, GNU Emacs | |
2119 | Lisp Reference Manual}. | |
2120 | ||
2121 | The following faces are, however, used in a non-standard fashion in | |
2122 | AWK mode: | |
2123 | ||
2124 | @table @asis | |
2125 | @item @code{font-lock-variable-name-face} | |
2126 | This face was intended for variable declarations. Since variables are | |
2127 | not declared in AWK, this face is used instead for AWK system | |
2128 | variables (such as @code{NF}) and ``Special File Names'' (such as | |
2129 | @code{"/dev/stderr"}). | |
2130 | ||
2131 | @item @code{font-lock-builtin-face} (Emacs)/@code{font-lock-preprocessor-face} (XEmacs) | |
2132 | This face is normally used for preprocessor directives in @ccmode{}. | |
2133 | There are no such things in AWK, so this face is used instead for | |
2134 | standard functions (such as @code{match}). | |
2135 | ||
2136 | @item @code{font-lock-string-face} | |
2137 | As well as being used for strings, including localizable strings, | |
2138 | (delimited by @samp{"} and @samp{_"}), this face is also used for AWK | |
2139 | regular expressions (delimited by @samp{/}). | |
2140 | ||
2141 | @item @code{font-lock-warning-face} (Emacs)/@code{c-invalid-face} (XEmacs) | |
2142 | This face highlights the following syntactically invalid AWK | |
2143 | constructs: | |
2144 | ||
2145 | @itemize @bullet | |
2146 | @item | |
2147 | An unterminated string or regular expression. Here the opening | |
2148 | delimiter (@samp{"} or @samp{/} or @samp{_"}) is displayed in | |
2149 | @code{font-lock-warning-face}. This is most noticeable when typing in a | |
2150 | new string/regular expression into a buffer, when the warning-face | |
2151 | serves as a continual reminder to terminate the construct. | |
2152 | ||
2153 | AWK mode fontifies unterminated strings/regular expressions | |
2154 | differently from other modes: Only the text up to the end of the line | |
2155 | is fontified as a string (escaped newlines being handled correctly), | |
2156 | rather than the text up to the next string quote. | |
2157 | ||
2158 | @item | |
2159 | A space between the function name and opening parenthesis when calling | |
2160 | a user function. The last character of the function name and the | |
2161 | opening parenthesis are highlighted. This font-locking rule will | |
2162 | spuriously highlight a valid concatenation expression where an | |
333f9019 | 2163 | identifier precedes a parenthesized expression. Unfortunately. |
4009494e GM |
2164 | |
2165 | @item | |
2166 | Whitespace following the @samp{\} in what otherwise looks like an | |
2167 | escaped newline. The @samp{\} is highlighted. | |
2168 | @end itemize | |
2169 | @end table | |
2170 | ||
2171 | ||
2172 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2173 | @node Config Basics, Custom Filling and Breaking, Font Locking, Top | |
2174 | @comment node-name, next, previous, up | |
2175 | @chapter Configuration Basics | |
2176 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2177 | ||
2178 | @cindex Emacs Initialization File | |
2179 | @cindex Configuration | |
2180 | You configure @ccmode{} by setting Lisp variables and calling (and | |
2181 | perhaps writing) Lisp functions@footnote{DON'T PANIC!!! This isn't | |
2182 | difficult.}, which is usually done by adding code to an Emacs | |
2183 | initialization file. This file might be @file{site-start.el} or | |
2184 | @file{.emacs} or @file{init.el} or @file{default.el} or perhaps some | |
2185 | other file. @xref{Init File,,,@emacsman{}, @emacsmantitle{}}. For | |
2186 | the sake of conciseness, we just call this file ``your @file{.emacs}'' | |
2187 | throughout the rest of the manual. | |
2188 | ||
2189 | Several of these variables (currently 16), are known collectively as | |
2190 | @dfn{style variables}. @ccmode{} provides a special mechanism, known | |
2191 | as @dfn{styles} to make it easier to set these variables as a group, | |
2192 | to ``inherit'' settings from one style into another, and so on. Style | |
2193 | variables remain ordinary Lisp variables, whose values can be read and | |
2194 | changed independently of the style system. @xref{Style Variables}. | |
2195 | ||
2196 | There are several ways you can write the code, depending on the | |
2197 | precise effect you want---they are described further down on this page. | |
2198 | If you are new to @ccmode{}, we suggest you begin with the simplest | |
2199 | method, ``Top-level commands or the customization interface''. | |
2200 | ||
2201 | If you make conflicting settings in several of these ways, the way | |
2202 | that takes precedence is the one that appears latest in this list: | |
2203 | @itemize @asis | |
2204 | @item | |
2205 | @table @asis | |
2206 | @item Style | |
22556bc5 | 2207 | @itemx File Style@footnote{In earlier versions of @ccmode{}, a File Style setting took precedence over any other setting apart from a File Local Variable setting.} |
4009494e GM |
2208 | @itemx Top-level command or ``customization interface'' |
2209 | @itemx Hook | |
22556bc5 | 2210 | @itemx File Local Variable setting |
4009494e GM |
2211 | @end table |
2212 | @end itemize | |
2213 | ||
2214 | Here is a summary of the different ways of writing your configuration | |
2215 | settings: | |
2216 | ||
2217 | @table @asis | |
2218 | @item Top-level commands or the ``customization interface'' | |
2219 | Most simply, you can write @code{setq} and similar commands at the top | |
2220 | level of your @file{.emacs} file. When you load a @ccmode{} buffer, | |
2221 | it initializes its configuration from these global values (at least, | |
2222 | for those settings you have given values to), so it makes sense to | |
2223 | have these @code{setq} commands run @emph{before} @ccmode{} is first | |
2224 | initialized---in particular, before any call to @code{desktop-read} | |
2225 | (@pxref{Saving Emacs Sessions,,, emacs, GNU Emacs Manual}). For | |
2226 | example, you might set c-basic-offset thus: | |
2227 | ||
2228 | @example | |
2229 | (setq c-basic-offset 4) | |
2230 | @end example | |
2231 | ||
2232 | You can use the more user friendly Customization interface instead, | |
2233 | but this manual does not cover in detail how that works. To do this, | |
2234 | start by typing @kbd{M-x customize-group @key{RET} c @key{RET}}. | |
2235 | @xref{Easy Customization,,,@emacsman{}, @emacsmantitle{}}. | |
2236 | @c The following note really belongs in the Emacs manual. | |
2237 | Emacs normally writes the customizations at the end of your | |
2238 | @file{.emacs} file. If you use @code{desktop-read}, you should edit | |
2239 | your @file{.emacs} to place the call to @code{desktop-read} @emph{after} | |
2240 | the customizations. | |
2241 | ||
2242 | The first initialization of @ccmode{} puts a snapshot of the | |
2243 | configuration settings into the special style @code{user}. | |
2244 | @xref{Built-in Styles}. | |
2245 | ||
2246 | For basic use of Emacs, either of these ways of configuring is | |
2247 | adequate. However, the settings are then the same in all @ccmode{} | |
2248 | buffers and it can be clumsy to communicate them between programmers. | |
2249 | For more flexibility, you'll want to use one (or both) of @ccmode{}'s | |
2250 | more sophisticated facilities, hooks and styles. | |
2251 | ||
2252 | @item Hooks | |
2253 | An Emacs @dfn{hook} is a place to put Lisp functions that you want | |
2254 | Emacs to execute later in specific circumstances. | |
2255 | @xref{Hooks,,,@lispref{}, @lispreftitle{}}. @ccmode{} supplies a main | |
2256 | hook and a language-specific hook for each language it supports - any | |
2257 | functions you put onto these hooks get executed as the last part of a | |
2258 | buffer's initialization. Typically you put most of your customization | |
2259 | within the main hook, and use the language-specific hooks to vary the | |
2260 | customization settings between language modes. For example, if you | |
2261 | wanted different (non-standard) values of @code{c-basic-offset} in C | |
2262 | Mode and Java Mode buffers, you could do it like this: | |
2263 | ||
2264 | @example | |
2265 | @group | |
2266 | (defun my-c-mode-hook () | |
2267 | (setq c-basic-offset 3)) | |
2268 | (add-hook 'c-mode-hook 'my-c-mode-hook) | |
2269 | ||
2270 | (defun my-java-mode-hook () | |
2271 | (setq c-basic-offset 6)) | |
2272 | (add-hook 'java-mode-hook 'my-java-mode-hook) | |
2273 | @end group | |
2274 | @end example | |
2275 | ||
2276 | See @ref{CC Hooks} for more details on the use of @ccmode{} hooks. | |
2277 | ||
2278 | @item Styles | |
2279 | A @ccmode{} @dfn{style} is a coherent collection of customizations | |
2280 | with a name. At any time, exactly one style is active in each | |
2281 | @ccmode{} buffer, either the one you have selected or a default. | |
2282 | @ccmode{} is delivered with several existing styles. Additionally, | |
2283 | you can create your own styles, possibly based on these existing | |
2284 | styles. If you worked in a programming team called the ``Free | |
2285 | Group'', which had its own coding standards, you might well have this | |
2286 | in your @file{.emacs} file: | |
2287 | ||
2288 | @example | |
2289 | (setq c-default-style '((java-mode . "java") | |
2290 | (awk-mode . "awk") | |
2291 | (other . "free-group-style"))) | |
2292 | @end example | |
2293 | ||
2294 | See @ref{Styles} for fuller details on using @ccmode{} styles and how | |
2295 | to create them. | |
2296 | ||
22556bc5 AM |
2297 | @item File Local Variable setting |
2298 | A @dfn{file local variable setting} is a setting which applies to an | |
2299 | individual source file. You put this in a @dfn{local variables list}, | |
2300 | a special block at the end of the source file (@pxref{Specifying File | |
2301 | Variables,,, @emacsman{}}). | |
2302 | ||
4009494e GM |
2303 | @item File Styles |
2304 | A @dfn{file style} is a rarely used variant of the ``style'' mechanism | |
22556bc5 AM |
2305 | described above, which applies to an individual source file. |
2306 | @xref{File Styles}. You use this by setting certain special variables | |
2307 | in a local variables list (@pxref{Specifying File Variables,,, | |
2308 | @emacsman{}}). | |
4009494e GM |
2309 | |
2310 | @item Hooks with Styles | |
2311 | For ultimate flexibility, you can use hooks and styles together. For | |
2312 | example, if your team were developing a product which required a | |
2313 | Linux driver, you'd probably want to use the ``linux'' style for the | |
2314 | driver, and your own team's style for the rest of the code. You | |
2315 | could achieve this with code like this in your @file{.emacs}: | |
2316 | ||
2317 | @example | |
2318 | @group | |
2319 | (defun my-c-mode-hook () | |
2320 | (c-set-style | |
2321 | (if (and (buffer-file-name) | |
2322 | (string-match "/usr/src/linux" (buffer-file-name))) | |
2323 | "linux" | |
2324 | "free-group-style"))) | |
2325 | (add-hook 'c-mode-hook 'my-c-mode-hook) | |
2326 | @end group | |
2327 | @end example | |
2328 | ||
2329 | In a programming team, a hook is a also a good place for each member | |
2330 | to put his own personal preferences. For example, you might be the | |
2331 | only person in your team who likes Auto-newline minor mode. You could | |
2332 | have it enabled by default by placing the following in your | |
2333 | @file{.emacs}: | |
2334 | ||
2335 | @example | |
2336 | @group | |
2337 | (defun my-turn-on-auto-newline () | |
2338 | (c-toggle-auto-newline 1)) | |
2339 | (add-hook 'c-mode-common-hook 'my-turn-on-auto-newline) | |
2340 | @end group | |
2341 | @end example | |
2342 | @end table | |
2343 | ||
2344 | @menu | |
2345 | * CC Hooks:: | |
2346 | * Style Variables:: | |
2347 | * Styles:: | |
2348 | @end menu | |
2349 | ||
2350 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2351 | @node CC Hooks, Style Variables, Config Basics, Config Basics | |
2352 | @comment node-name, next, previous, up | |
2353 | @section Hooks | |
2354 | @cindex mode hooks | |
2355 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2356 | @c The node name is "CC Hooks" rather than "Hooks" because of a bug in | |
2357 | @c some older versions of Info, e.g. the info.el in GNU Emacs 21.3. | |
2358 | @c If you go to "Config Basics" and hit <CR> on the xref to "CC | |
2359 | @c Hooks" the function Info-follow-reference searches for "*Note: CC | |
2360 | @c Hooks" from the beginning of the page. If this node were instead | |
2361 | @c named "Hooks", that search would spuriously find "*Note: | |
2362 | @c Hooks(elisp)" and go to the wrong node. | |
2363 | ||
2364 | @ccmode{} provides several hooks that you can use to customize the | |
2365 | mode for your coding style. The main hook is | |
2366 | @code{c-mode-common-hook}; typically, you'll put the bulk of your | |
2367 | customizations here. In addition, each language mode has its own | |
2368 | hook, allowing you to fine tune your settings individually for the | |
2369 | different @ccmode{} languages, and there is a package initialization | |
2370 | hook. Finally, there is @code{c-special-indent-hook}, which enables | |
2371 | you to solve anomalous indentation problems. It is described in | |
2372 | @ref{Other Indentation}, not here. All these hooks adhere to the | |
2373 | standard Emacs conventions. | |
2374 | ||
2375 | When you open a buffer, @ccmode{} first initializes it with the | |
2376 | currently active style (@pxref{Styles}). Then it calls | |
2377 | @code{c-mode-common-hook}, and finally it calls the language-specific | |
2378 | hook. Thus, any style settings done in these hooks will override | |
2379 | those set by @code{c-default-style}. | |
2380 | ||
2381 | @defvar c-initialization-hook | |
2382 | @vindex initialization-hook (c-) | |
2383 | Hook run only once per Emacs session, when @ccmode{} is initialized. | |
2384 | This is a good place to change key bindings (or add new ones) in any | |
2385 | of the @ccmode{} key maps. @xref{Sample .emacs File}. | |
2386 | @end defvar | |
2387 | ||
2388 | @defvar c-mode-common-hook | |
2389 | @vindex mode-common-hook (c-) | |
2390 | Common hook across all languages. It's run immediately before the | |
2391 | language specific hook. | |
2392 | @end defvar | |
2393 | ||
2394 | @defvar c-mode-hook | |
2395 | @defvarx c++-mode-hook | |
2396 | @defvarx objc-mode-hook | |
2397 | @defvarx java-mode-hook | |
2398 | @defvarx idl-mode-hook | |
2399 | @defvarx pike-mode-hook | |
2400 | @defvarx awk-mode-hook | |
2401 | The language specific mode hooks. The appropriate one is run as the | |
2402 | last thing when you enter that language mode. | |
2403 | @end defvar | |
2404 | ||
2405 | Although these hooks are variables defined in @ccmode{}, you can give | |
2406 | them values before @ccmode{}'s code is loaded---indeed, this is the | |
2407 | only way to use @code{c-initialization-hook}. Their values aren't | |
2408 | overwritten when @ccmode{} gets loaded. | |
2409 | ||
2410 | Here's a simplified example of what you can add to your @file{.emacs} | |
2411 | file to do things whenever any @ccmode{} language is edited. See the | |
2412 | Emacs manuals for more information on customizing Emacs via hooks. | |
2413 | @xref{Sample .emacs File}, for a more complete sample @file{.emacs} | |
2414 | file. | |
2415 | ||
2416 | @example | |
2417 | (defun my-c-mode-common-hook () | |
2418 | ;; my customizations for all of c-mode and related modes | |
2419 | (no-case-fold-search) | |
2420 | ) | |
2421 | (add-hook 'c-mode-common-hook 'my-c-mode-common-hook) | |
2422 | @end example | |
2423 | ||
2424 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2425 | @node Style Variables, Styles, CC Hooks, Config Basics | |
2426 | @comment node-name, next, previous, up | |
2427 | @section Style Variables | |
2428 | @cindex styles | |
2429 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2430 | ||
2431 | @cindex style variables | |
2432 | The variables that @ccmode{}'s style system control are called | |
2433 | @dfn{style variables}. Note that style variables are ordinary Lisp | |
2434 | variables, which the style system initializes; you can change their | |
2435 | values at any time (e.g. in a hook function). The style system can | |
2436 | also set other variables, to some extent. @xref{Styles}. | |
2437 | ||
2438 | @dfn{Style variables} are handled specially in several ways: | |
2439 | ||
2440 | @itemize @bullet | |
2441 | @item | |
2442 | Style variables are by default buffer-local variables. However, they | |
2443 | can instead be made global by setting | |
2444 | @code{c-style-variables-are-local-p} to @code{nil} before @ccmode{} is | |
2445 | initialized. | |
2446 | ||
2447 | @item | |
2448 | @vindex c-old-style-variable-behavior | |
2449 | @vindex old-style-variable-behavior (c-) | |
2450 | The default global binding of any style variable (with two exceptions | |
2451 | - see below) is the special symbol @code{set-from-style}. When the | |
2452 | style system initializes a buffer-local copy of a style variable for a | |
2453 | @ccmode{} buffer, if its global binding is still that symbol then it | |
2454 | will be set from the current style. Otherwise it will retain its | |
2455 | global default@footnote{This is a big change from versions of | |
2456 | @ccmode{} earlier than 5.26, where such settings would get overridden | |
2457 | by the style system unless special precautions were taken. That was | |
2458 | changed since it was counterintuitive and confusing, especially to | |
2459 | novice users. If your configuration depends on the old overriding | |
2460 | behavior, you can set the variable | |
2461 | @code{c-old-style-variable-behavior} to non-@code{nil}.}. This | |
2462 | ``otherwise'' happens, for example, when you've set the variable with | |
2463 | @code{setq} at the top level of your @file{.emacs} (@pxref{Config | |
2464 | Basics}). | |
2465 | ||
2466 | @item | |
2467 | The style variable @code{c-offsets-alist} (@pxref{c-offsets-alist}) is | |
2468 | an association list with an element for each syntactic symbol. It's | |
2469 | handled a little differently from the other style variables. It's | |
2470 | default global binding is the empty list @code{nil}, rather than | |
2471 | @code{set-from-style}. Before the style system is initialized, you | |
2472 | can add individual elements to @code{c-offsets-alist} by calling | |
2473 | @code{c-set-offset}(@pxref{c-offsets-alist}) just like you would set | |
2474 | other style variables with @code{setq}. Those elements will then | |
2475 | prevail when the style system later initializes a buffer-local copy of | |
2476 | @code{c-offsets-alist}. | |
2477 | ||
2478 | @item | |
2479 | The style variable @code{c-special-indent-hook} is also handled in a | |
2480 | special way. Styles can only add functions to this hook, not remove | |
2481 | them, so any global settings you put on it are always | |
2482 | preserved@footnote{This did not change in version 5.26.}. The value | |
2483 | you give this variable in a style definition can be either a function | |
2484 | or a list of functions. | |
2485 | ||
2486 | @item | |
2487 | The global bindings of the style variables get captured in the special | |
2488 | @code{user} style when the style system is first initialized. | |
2489 | @xref{Built-in Styles}, for details. | |
2490 | @end itemize | |
2491 | ||
2492 | The style variables are:@* | |
2493 | @code{c-indent-comment-alist}, | |
2494 | @code{c-indent-comments-syntactically-p} (@pxref{Indentation | |
2495 | Commands});@* | |
2496 | @code{c-doc-comment-style} (@pxref{Doc Comments});@* | |
2497 | @code{c-block-comment-prefix}, @code{c-comment-prefix-regexp} | |
2498 | (@pxref{Custom Filling and Breaking});@* | |
2499 | @code{c-hanging-braces-alist} (@pxref{Hanging Braces});@* | |
2500 | @code{c-hanging-colons-alist} (@pxref{Hanging Colons});@* | |
2501 | @code{c-hanging-semi&comma-criteria} (@pxref{Hanging Semicolons and | |
2502 | Commas});@* | |
2503 | @code{c-cleanup-list} (@pxref{Clean-ups});@* | |
2504 | @code{c-basic-offset} (@pxref{Customizing Indentation});@* | |
2505 | @code{c-offsets-alist} (@pxref{c-offsets-alist});@* | |
2506 | @code{c-comment-only-line-offset} (@pxref{Comment Line-Up});@* | |
2507 | @code{c-special-indent-hook}, @code{c-label-minimum-indentation} | |
2508 | (@pxref{Other Indentation});@* | |
2509 | @code{c-backslash-column}, @code{c-backslash-max-column} | |
2510 | (@pxref{Custom Macros}). | |
2511 | ||
2512 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2513 | @node Styles, , Style Variables, Config Basics | |
2514 | @comment node-name, next, previous, up | |
2515 | @section Styles | |
2516 | @cindex styles | |
2517 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2518 | ||
2519 | By @dfn{style} we mean the layout of the code---things like how many | |
2520 | columns to indent a block of code, whether an opening brace gets | |
2521 | indented to the level of the code it encloses, or of the construct | |
2522 | that introduces it, or ``hangs'' at the end of a line. | |
2523 | ||
2524 | Most people only need to edit code formatted in just a few well-defined | |
2525 | and consistent styles. For example, their organization might impose a | |
2526 | ``blessed'' style that all its programmers must conform to. Similarly, | |
2527 | people who work on GNU software will have to use the GNU coding style. | |
2528 | Some shops are more lenient, allowing a variety of coding styles, and as | |
2529 | programmers come and go, there could be a number of styles in use. For | |
2530 | this reason, @ccmode{} makes it convenient for you to set up logical | |
2531 | groupings of customizations called @dfn{styles}, associate a single name | |
2532 | for any particular style, and pretty easily start editing new or | |
2533 | existing code using these styles. | |
2534 | ||
847ccf7c AM |
2535 | As an alternative to writing a style definition yourself, you can have |
2536 | @ccmode{} @dfn{guess} (at least part of) your style by looking at an | |
2537 | already formatted piece of your code, @ref{Guessing the Style}. | |
2538 | ||
4009494e | 2539 | @menu |
91af3942 PE |
2540 | * Built-in Styles:: |
2541 | * Choosing a Style:: | |
2542 | * Adding Styles:: | |
2543 | * Guessing the Style:: | |
2544 | * File Styles:: | |
4009494e GM |
2545 | @end menu |
2546 | ||
4009494e GM |
2547 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
2548 | @node Built-in Styles, Choosing a Style, Styles, Styles | |
2549 | @comment node-name, next, previous, up | |
2550 | @subsection Built-in Styles | |
2551 | @cindex styles, built-in | |
2552 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2553 | ||
2554 | If you're lucky, one of @ccmode{}'s built-in styles might be just | |
2555 | what you're looking for. These are: | |
2556 | ||
2557 | @table @code | |
2558 | @item gnu | |
2559 | @cindex GNU style | |
2560 | Coding style blessed by the Free Software Foundation | |
2561 | for C code in GNU programs. | |
2562 | ||
2563 | @item k&r | |
2564 | @cindex K&R style | |
2565 | The classic Kernighan and Ritchie style for C code. | |
2566 | ||
2567 | @item bsd | |
2568 | @cindex BSD style | |
2569 | Also known as ``Allman style'' after Eric Allman. | |
2570 | ||
2571 | @item whitesmith | |
2572 | @cindex Whitesmith style | |
2573 | Popularized by the examples that came with Whitesmiths C, an early | |
2574 | commercial C compiler. | |
2575 | ||
2576 | @item stroustrup | |
2577 | @cindex Stroustrup style | |
2578 | The classic Stroustrup style for C++ code. | |
2579 | ||
2580 | @item ellemtel | |
2581 | @cindex Ellemtel style | |
2582 | Popular C++ coding standards as defined by ``Programming in C++, Rules | |
2583 | and Recommendations,'' Erik Nyquist and Mats Henricson, | |
2584 | Ellemtel@footnote{This document is available at | |
2585 | @uref{http://www.doc.ic.ac.uk/lab/cplus/c++.rules/} among other | |
2586 | places.}. | |
2587 | @c N.B. This URL was still valid at 2005/8/28 (ACM). | |
2588 | ||
2589 | @item linux | |
2590 | @cindex Linux style | |
2591 | C coding standard for Linux (the kernel). | |
2592 | ||
2593 | @item python | |
2594 | @cindex Python style | |
2595 | C coding standard for Python extension modules@footnote{Python is a | |
2596 | high level scripting language with a C/C++ foreign function interface. | |
2597 | For more information, see @uref{http://www.python.org/}.}. | |
2598 | ||
2599 | @item java | |
2600 | @cindex Java style | |
2601 | The style for editing Java code. Note that the default | |
2602 | value for @code{c-default-style} installs this style when you enter | |
2603 | @code{java-mode}. | |
2604 | ||
2605 | @item awk | |
2606 | @cindex AWK style | |
2607 | The style for editing AWK code. Note that the default value for | |
2608 | @code{c-default-style} installs this style when you enter | |
2609 | @code{awk-mode}. | |
2610 | ||
2611 | @item user | |
2612 | @cindex User style | |
2613 | This is a special style created by you. It consists of the factory | |
2614 | defaults for all the style variables as modified by the customizations | |
2615 | you do either with the Customization interface or by writing | |
2616 | @code{setq}s and @code{c-set-offset}s at the top level of your | |
2617 | @file{.emacs} file (@pxref{Config Basics}). The style system creates | |
2618 | this style as part of its initialization and doesn't modify it | |
2619 | afterwards. | |
2620 | @end table | |
2621 | ||
2622 | ||
2623 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2624 | @node Choosing a Style, Adding Styles, Built-in Styles, Styles | |
2625 | @comment node-name, next, previous, up | |
2626 | @subsection Choosing a Style | |
2627 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2628 | ||
2629 | When you create a new buffer, its style will be set from | |
2630 | @code{c-default-style}. The factory default is the style @code{gnu}, | |
2631 | except in Java and AWK modes where it's @code{java} and @code{awk}. | |
2632 | ||
2633 | Remember that if you set a style variable with the Customization | |
2634 | interface or at the top level of your @file{.emacs} file before the | |
2f0c93d1 | 2635 | style system is initialized (@pxref{Config Basics}), this setting will |
4009494e GM |
2636 | override the one that the style system would have given the variable. |
2637 | ||
2638 | To set a buffer's style interactively, use the command @kbd{C-c .} | |
2639 | (@pxref{Other Commands}). To set it from a file's local variable | |
2640 | list, @ref{File Styles}. | |
2641 | ||
2642 | @defopt c-default-style | |
2643 | @vindex default-style (c-) | |
2644 | This variable specifies which style to install by default in new | |
2645 | buffers. It takes either a style name string, or an association list | |
2646 | of major mode symbols to style names: | |
2647 | ||
2648 | @enumerate | |
2649 | @item | |
2650 | When @code{c-default-style} is a string, it must be an existing style | |
2651 | name. This style is then used for all modes. | |
2652 | ||
2653 | @item | |
2654 | When @code{c-default-style} is an association list, the mode language | |
2655 | is looked up to find a style name string. | |
2656 | ||
2657 | @item | |
2658 | If @code{c-default-style} is an association list where the mode | |
2659 | language mode isn't found then the special symbol @samp{other} is | |
2660 | looked up. If it's found then the associated style is used. | |
2661 | ||
2662 | @item | |
2663 | If @samp{other} is not found then the @samp{gnu} style is used. | |
2664 | @end enumerate | |
2665 | ||
2666 | In all cases, the style described in @code{c-default-style} is installed | |
2667 | @emph{before} the language hooks are run, so you can always override | |
2668 | this setting by including an explicit call to @code{c-set-style} in your | |
2669 | language mode hook, or in @code{c-mode-common-hook}. | |
2670 | ||
2671 | The standard value of @code{c-default-style} is @w{@code{((java-mode | |
2672 | . "java") (awk-mode . "awk") (other . "gnu"))}}. | |
2673 | @end defopt | |
2674 | ||
2675 | @defvar c-indentation-style | |
2676 | @vindex indentation-style (c-) | |
2677 | This variable always contains the buffer's current style name, as a | |
2678 | string. | |
2679 | @end defvar | |
2680 | ||
4009494e | 2681 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
847ccf7c | 2682 | @node Adding Styles, Guessing the Style, Choosing a Style, Styles |
4009494e GM |
2683 | @comment node-name, next, previous, up |
2684 | @subsection Adding and Amending Styles | |
2685 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2686 | ||
2687 | If none of the built-in styles is appropriate, you'll probably want to | |
2688 | create a new @dfn{style definition}, possibly based on an existing | |
2689 | style. To do this, put the new style's settings into a list with the | |
2690 | following format - the list can then be passed as an argument to the | |
2691 | function @code{c-add-style}. You can see an example of a style | |
2692 | definition in @ref{Sample .emacs File}. | |
2693 | ||
2694 | @cindex style definition | |
2695 | @c @defvr {List} style definition | |
2696 | @table @asis | |
2697 | @item Structure of a Style Definition List | |
2698 | ([@var{base-style}] [(@var{variable} . @var{value}) @dots{}]) | |
2699 | ||
2700 | Optional @var{base-style}, if present, must be a string which is the | |
2701 | name of the @dfn{base style} from which this style inherits. At most | |
2702 | one @var{base-style} is allowed in a style definition. If | |
2703 | @var{base-style} is not specified, the style inherits from the table | |
2704 | of factory default values@footnote{This table is stored internally in | |
2705 | the variable c-fallback-style.} instead. All styles eventually | |
2706 | inherit from this internal table. Style loops generate errors. The | |
2707 | list of pre-existing styles can be seen in @ref{Built-in Styles}. | |
2708 | ||
2709 | The dotted pairs (@var{variable} . @var{value}) each consist of a | |
2710 | variable and the value it is to be set to when the style is later | |
2711 | activated.@footnote{Note that if the variable has been given a value | |
2712 | by the Customization interface or a @code{setq} at the top level of | |
2713 | your @file{.emacs}, this value will override the one the style system | |
2714 | tries to give it. @xref{Config Basics}.} The variable can be either a | |
2715 | @ccmode{} style variable or an arbitrary Emacs variable. In the | |
2716 | latter case, it is @emph{not} made buffer-local by the @ccmode{} style | |
2717 | system. | |
2718 | @c @end defvr | |
2719 | ||
2720 | Two variables are treated specially in the dotted pair list: | |
2721 | ||
2722 | @table @code | |
2723 | @item c-offsets-alist | |
2724 | The value is in turn a list of dotted pairs of the form | |
2725 | ||
2726 | @example | |
2727 | (@r{@var{syntactic-symbol}} . @r{@var{offset}}) | |
2728 | @end example | |
2729 | ||
2730 | as described in @ref{c-offsets-alist}. These are passed to | |
2731 | @code{c-set-offset} so there is no need to set every syntactic symbol | |
2732 | in your style, only those that are different from the inherited style. | |
2733 | ||
2734 | @item c-special-indent-hook | |
2735 | The value is added to @code{c-special-indent-hook} using | |
2736 | @code{add-hook}, so any functions already on it are kept. If the value | |
2737 | is a list, each element of the list is added with @code{add-hook}. | |
2738 | @end table | |
2739 | @end table | |
2740 | ||
2741 | Styles are kept in the @code{c-style-alist} variable, but you | |
2742 | should never modify this variable directly. Instead, @ccmode{} | |
2743 | provides the function @code{c-add-style} for this purpose. | |
2744 | ||
2745 | @defun c-add-style stylename description &optional set-p | |
2746 | @findex add-style (c-) | |
2747 | Add or update a style called @var{stylename}, a string. | |
2748 | @var{description} is the new style definition in the form described | |
2749 | above. If @var{stylename} already exists in @code{c-style-alist} then | |
2750 | it is replaced by @var{description}. (Note, this replacement is | |
2751 | total. The old style is @emph{not} merged into the new one.) | |
2752 | Otherwise, a new style is added. | |
2753 | ||
2754 | If the optional @var{set-p} is non-@code{nil} then the new style is | |
2755 | applied to the current buffer as well. The use of this facility is | |
2756 | deprecated and it might be removed from @ccmode{} in a future release. | |
2757 | You should use @code{c-set-style} instead. | |
2758 | ||
2759 | The sample @file{.emacs} file provides a concrete example of how a new | |
2760 | style can be added and automatically set. @xref{Sample .emacs File}. | |
2761 | @end defun | |
2762 | ||
2763 | @defvar c-style-alist | |
2764 | @vindex style-alist (c-) | |
2765 | This is the variable that holds the definitions for the styles. It | |
2766 | should not be changed directly; use @code{c-add-style} instead. | |
2767 | @end defvar | |
2768 | ||
847ccf7c AM |
2769 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
2770 | @node Guessing the Style, File Styles, Adding Styles, Styles | |
2771 | @comment node-name, next, previous, up | |
2772 | @subsection Guessing the Style | |
2773 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2774 | ||
2775 | Instead of specifying a style, you can get @ccmode{} to @dfn{guess} | |
2776 | your style by examining an already formatted code buffer. @ccmode{} | |
2777 | then determines the ''most frequent'' offset (@pxref{c-offsets-alist}) | |
2778 | for each of the syntactic symbols (@pxref{Indentation Engine Basics}) | |
2779 | encountered in the buffer, and the ''most frequent'' value of | |
2780 | c-basic-offset (@pxref{Customizing Indentation}), then merges the | |
2781 | current style with these ''guesses'' to form a new style. This | |
2782 | combined style is known as the @dfn{guessed style}. | |
2783 | ||
2784 | To do this, call @code{c-guess} (or one of the other 5 guessing | |
2785 | commands) on your sample buffer. The analysis of your code may take | |
2786 | some time. | |
2787 | ||
2788 | You can then set the guessed style in any @ccmode{} buffer with | |
2789 | @code{c-guess-install}. You can display the style with | |
2790 | @code{c-guess-view}, and preserve it by copying it into your | |
2791 | @file{.emacs} for future use, preferably after editing it. | |
2792 | ||
2793 | @table @asis | |
2794 | @item @kbd{M-x c-guess-no-install} | |
2795 | @itemx @kbd{M-x c-guess-buffer-no-install} | |
2796 | @itemx @kbd{M-x c-guess-region-no-install} | |
2797 | @findex c-guess-no-install | |
2798 | @findex c-guess-buffer-no-install | |
2799 | @findex c-guess-region-no-install | |
2800 | @findex guess-no-install (c-) | |
2801 | @findex guess-buffer-no-install (c-) | |
2802 | @findex guess-region-no-install (c-) | |
2803 | These commands analyze a part of the current buffer and guess the | |
2804 | style from it. | |
2805 | ||
2806 | The part of the buffer examined is either the region | |
2807 | (@code{c-guess-region-no-install}), the entire buffer | |
2808 | (@code{c-guess-buffer-no-install}), or the first | |
2809 | @code{c-guess-region-max} bytes (@code{c-guess-no-install}). | |
2810 | ||
2811 | Each of these commands can be given an optional prefix argument. This | |
2812 | instructs @ccmode{} to combine the new guesses with the current | |
2813 | guesses before forming the guessed style. | |
2814 | @end table | |
2815 | ||
2816 | @table @asis | |
2817 | @item @kbd{M-x c-guess} | |
2818 | @itemx @kbd{M-x c-guess-buffer} | |
2819 | @itemx @kbd{M-x c-guess-region} | |
2820 | @findex c-guess | |
2821 | @findex c-guess-buffer | |
2822 | @findex c-guess-region | |
2823 | @findex guess (c-) | |
2824 | @findex guess-buffer (c-) | |
2825 | @findex guess-region (c-) | |
2826 | These commands analyze a part of the current buffer, guess the style | |
2827 | from it, then install the guessed style on the buffer. The guessed | |
2828 | style is given a name based on the buffer's absolute file name, and | |
2829 | you can then set this style on any @ccmode{} buffer with @kbd{C-c .}. | |
2830 | ||
2831 | The part of the buffer examined is either the region | |
2832 | (@code{c-guess-region}), the entire buffer (@code{c-guess-buffer}), or | |
2833 | the first @code{c-guess-region-max} bytes (@code{c-guess}). | |
2834 | ||
2835 | Each of these commands can be given an optional prefix argument. This | |
2836 | instructs @ccmode{} to combine the new guesses with the current | |
2837 | guesses before forming the guessed style. | |
2838 | @end table | |
2839 | ||
2840 | @defopt c-guess-region-max | |
2841 | @vindex guess-region-max (c-) | |
2842 | This variable, default 50000, is the size in bytes of the buffer | |
2843 | portion examined by c-guess and c-guess-no-install. If set to | |
2844 | @code{nil}, the entire buffer is examined. | |
2845 | @end defopt | |
2846 | ||
2847 | @defopt c-guess-offset-threshold | |
2848 | @vindex guess-offset-threshold (c-) | |
2849 | This variable, default 10, is the maximum offset, either outwards or | |
2850 | inwards, which will be taken into account by the analysis process. | |
2851 | Any offset bigger than this will be ignored. For no limit, set this | |
2852 | variable to a large number. | |
2853 | @end defopt | |
2854 | ||
2855 | @table @asis | |
2856 | @item @kbd{M-x c-guess-install} | |
2857 | @findex c-guess-install | |
2858 | @findex guess-install (c-) | |
2859 | ||
2860 | Set the current buffer's style to the guessed style. This prompts you | |
2861 | to enter an optional new style name to give to the guessed style. By | |
2862 | default, this name is based on the buffer's absolute file name. You | |
2863 | can then use this style like any other. | |
2864 | ||
2865 | @item @kbd{M-x c-guess-view} | |
2866 | @findex c-guess-view | |
2867 | @findex guess-view (c-) | |
2868 | Display the most recently guessed style in a temporary buffer. This | |
2869 | display is in the form of a @code{c-add-style} form (@pxref{Adding | |
2870 | Styles}) which can be easily copied to your @file{.emacs}. You will | |
2871 | probably want to edit it first. | |
2872 | ||
2873 | The display of the guessed style contains these elements: | |
2874 | ||
2875 | @table @asis | |
2876 | @item Placeholder Name | |
2877 | You should replace this with a style name of your own. | |
2878 | @item Parent Style | |
2879 | The style current when the guessing began, from which the guessed | |
2880 | style inherits (@pxref{Config Basics}) the settings which weren't | |
2881 | guessed. | |
2882 | @item Guessed Offsets | |
2883 | These are the core result of the guessing process. Each of them is | |
2884 | marked by a comment. | |
2885 | @item Inherited Offsets | |
2886 | These are syntactic offsets which have been taken over from the parent | |
2887 | style. To avoid possible future conflicts, you should remove either | |
2888 | these offsets or the parent style name. | |
2889 | @end table | |
2890 | @end table | |
4009494e GM |
2891 | |
2892 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
847ccf7c | 2893 | @node File Styles, , Guessing the Style, Styles |
4009494e GM |
2894 | @comment node-name, next, previous, up |
2895 | @subsection File Styles | |
2896 | @cindex styles, file local | |
2897 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2898 | ||
2899 | @cindex file local variables | |
2900 | ||
2901 | The Emacs manual describes how you can customize certain variables on a | |
2902 | per-file basis by including a @dfn{file local variable} block at the end | |
2903 | of the file (@pxref{File Variables,, Local Variables in Files, @emacsman{}, | |
2904 | @emacsmantitle{}}). | |
2905 | ||
2906 | So far, you've only seen a functional interface for setting styles in | |
2907 | @ccmode{}, and this can't be used here. @ccmode{} fills the gap by | |
2908 | providing two variables for use in a file's local variable list. | |
2909 | Don't use them anywhere else! These allow you to customize the style | |
2910 | on a per-file basis: | |
2911 | ||
2912 | @defvar c-file-style | |
2913 | @vindex file-style (c-) | |
2914 | Set this variable to a style name string in the Local Variables list. | |
2915 | From now on, when you visit the file, @ccmode{} will automatically set | |
2916 | the file's style to this one using @code{c-set-style}. | |
2917 | @end defvar | |
2918 | ||
2919 | @defvar c-file-offsets | |
2920 | @vindex file-offsets (c-) | |
2921 | Set this variable (in the Local Variables list) to an association list | |
2922 | of the same format as @code{c-offsets-alist}. From now on, when you | |
2923 | visit the file, @ccmode{} will automatically institute these offsets | |
2924 | using @code{c-set-offset}. | |
2925 | @end defvar | |
2926 | ||
2927 | Note that file style settings (i.e. @code{c-file-style}) are applied | |
2928 | before file offset settings | |
2929 | (i.e. @code{c-file-offsets})@footnote{Also, if either of these are set | |
2930 | in a file's local variable section, all the style variable values are | |
2931 | made local to that buffer, even if | |
2932 | @code{c-style-variables-are-local-p} is @code{nil}. Since this | |
2933 | variable is virtually always non-@code{nil} anyhow, you're unlikely to | |
2934 | notice this effect.}. | |
2935 | ||
22556bc5 AM |
2936 | If you set any variable by the file local variables mechanism, that |
2937 | setting takes priority over all other settings, even those in your | |
2938 | mode hooks (@pxref{CC Hooks}). Any individual setting of a variable | |
2939 | will override one made through @code{c-file-style} or | |
2940 | @code{c-file-offsets}. | |
4009494e GM |
2941 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
2942 | @node Custom Filling and Breaking, Custom Auto-newlines, Config Basics, Top | |
2943 | @comment node-name, next, previous, up | |
2944 | @chapter Customizing Filling and Line Breaking | |
2945 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
2946 | ||
2947 | Since there's a lot of normal text in comments and string literals, | |
2948 | @ccmode{} provides features to edit these like in text mode. It does | |
2949 | this by hooking in on the different line breaking functions and tuning | |
2950 | relevant variables as necessary. | |
2951 | ||
2952 | @vindex c-comment-prefix-regexp | |
2953 | @vindex comment-prefix-regexp (c-) | |
2954 | @cindex comment line prefix | |
2955 | @vindex comment-start | |
2956 | @vindex comment-end | |
2957 | @vindex comment-start-skip | |
2958 | @vindex paragraph-start | |
2959 | @vindex paragraph-separate | |
2960 | @vindex paragraph-ignore-fill-prefix | |
2961 | @vindex adaptive-fill-mode | |
2962 | @vindex adaptive-fill-regexp | |
2963 | @vindex adaptive-fill-first-line-regexp | |
2964 | To make Emacs recognize comments and treat text in them as normal | |
2965 | paragraphs, @ccmode{} makes several standard | |
2966 | variables@footnote{@code{comment-start}, @code{comment-end}, | |
2967 | @code{comment-start-skip}, @code{paragraph-start}, | |
2968 | @code{paragraph-separate}, @code{paragraph-ignore-fill-prefix}, | |
2969 | @code{adaptive-fill-mode}, @code{adaptive-fill-regexp}, and | |
2970 | @code{adaptive-fill-first-line-regexp}.} buffer-local and modifies them | |
2971 | according to the language syntax and the comment line prefix. | |
2972 | ||
2973 | @defopt c-comment-prefix-regexp | |
2974 | @vindex comment-prefix-regexp (c-) | |
2975 | This style variable contains the regexp used to recognize the | |
2976 | @dfn{comment line prefix}, which is the line decoration that starts | |
2977 | every line in a comment. The variable is either the comment line | |
2978 | prefix itself, or (more usually) an association list with different | |
2979 | values for different languages. The symbol for the major mode is | |
2980 | looked up in the alist to get the regexp for the language, and if it | |
2981 | isn't found then the special symbol @samp{other} is looked up instead. | |
2982 | ||
2983 | When a comment line gets divided by @kbd{M-j} or the like, @ccmode{} | |
2f0c93d1 | 2984 | inserts the comment line prefix from a neighboring line at the start |
4009494e GM |
2985 | of the new line. The default value of c-comment-prefix-regexp is |
2986 | @samp{//+\\|\\**}, which matches C++ style line comments like | |
2987 | ||
2988 | @example | |
2989 | // blah blah | |
2990 | @end example | |
2991 | ||
2992 | @noindent | |
2993 | with two or more slashes in front of them, and the second and | |
2994 | subsequent lines of C style block comments like | |
2995 | ||
2996 | @example | |
2997 | @group | |
2998 | /* | |
2999 | * blah blah | |
3000 | */ | |
3001 | @end group | |
3002 | @end example | |
3003 | ||
3004 | @noindent | |
3005 | with zero or more stars at the beginning of every line. If you change | |
3006 | this variable, please make sure it still matches the comment starter | |
3007 | (i.e. @code{//}) of line comments @emph{and} the line prefix inside | |
3008 | block comments. | |
3009 | ||
3010 | @findex c-setup-paragraph-variables | |
3011 | @findex setup-paragraph-variables (c-) | |
3012 | Also note that since @ccmode{} uses the value of | |
3013 | @code{c-comment-prefix-regexp} to set up several other variables at | |
3014 | mode initialization, there won't be any effect if you just change it | |
3015 | inside a @ccmode{} buffer. You need to call the command | |
3016 | @code{c-setup-paragraph-variables} too, to update those other | |
3017 | variables. That's also the case if you modify | |
3018 | @code{c-comment-prefix-regexp} in a mode hook, since @ccmode{} will | |
3019 | already have set up these variables before calling the hook. | |
3020 | @end defopt | |
3021 | ||
3022 | In comments, @ccmode{} uses @code{c-comment-prefix-regexp} to adapt | |
3023 | the line prefix from the other lines in the comment. | |
3024 | ||
3025 | @vindex adaptive-fill-mode | |
3026 | @cindex Adaptive Fill mode | |
3027 | @ccmode{} uses adaptive fill mode (@pxref{Adaptive Fill,,, emacs, GNU | |
3028 | Emacs Manual}) to make Emacs correctly keep the line prefix when | |
3029 | filling paragraphs. That also makes Emacs preserve the text | |
3030 | indentation @emph{inside} the comment line prefix. E.g. in the | |
3031 | following comment, both paragraphs will be filled with the left | |
3032 | margins of the texts kept intact: | |
3033 | ||
3034 | @example | |
3035 | @group | |
3036 | /* Make a balanced b-tree of the nodes in the incoming | |
3037 | * stream. But, to quote the famous words of Donald E. | |
3038 | * Knuth, | |
3039 | * | |
3040 | * Beware of bugs in the above code; I have only | |
3041 | * proved it correct, not tried it. | |
3042 | */ | |
3043 | @end group | |
3044 | @end example | |
3045 | ||
3046 | @findex c-setup-filladapt | |
3047 | @findex setup-filladapt (c-) | |
3048 | @findex filladapt-mode | |
3049 | @vindex filladapt-mode | |
3050 | @cindex Filladapt mode | |
3051 | It's also possible to use other adaptive filling packages, notably Kyle | |
3052 | E. Jones' Filladapt package@footnote{It's available from | |
3053 | @uref{http://www.wonderworks.com/}. As of version 2.12, it does however | |
3054 | lack a feature that makes it work suboptimally when | |
3055 | @code{c-comment-prefix-regexp} matches the empty string (which it does | |
3056 | by default). A patch for that is available from | |
3057 | @uref{http://cc-mode.sourceforge.net/,, the CC Mode web site}.}, | |
3058 | @c 2005/11/22: The above is still believed to be the case. | |
3059 | which handles things like bulleted lists nicely. There's a convenience | |
3060 | function @code{c-setup-filladapt} that tunes the relevant variables in | |
3061 | Filladapt for use in @ccmode{}. Call it from a mode hook, e.g. with | |
3062 | something like this in your @file{.emacs}: | |
3063 | ||
3064 | @example | |
3065 | (defun my-c-mode-common-hook () | |
3066 | (c-setup-filladapt) | |
3067 | (filladapt-mode 1)) | |
3068 | (add-hook 'c-mode-common-hook 'my-c-mode-common-hook) | |
3069 | @end example | |
3070 | ||
3071 | @defopt c-block-comment-prefix | |
3072 | @vindex block-comment-prefix (c-) | |
3073 | @vindex c-comment-continuation-stars | |
3074 | @vindex comment-continuation-stars (c-) | |
3075 | Normally the comment line prefix inserted for a new line inside a | |
3076 | comment is deduced from other lines in it. However there's one | |
3077 | situation when there's no hint about what the prefix should look like, | |
3078 | namely when a block comment is broken for the first time. This style | |
3079 | variable@footnote{In versions before 5.26, this variable was called | |
3080 | @code{c-comment-continuation-stars}. As a compatibility measure, | |
3081 | @ccmode{} still uses the value on that variable if it's set.} is used | |
3082 | then as the comment prefix. It defaults to @samp{* | |
3083 | }@footnote{Actually, this default setting of | |
3084 | @code{c-block-comment-prefix} typically gets overridden by the default | |
3085 | style @code{gnu}, which sets it to blank. You can see the line | |
3086 | splitting effect described here by setting a different style, | |
3087 | e.g. @code{k&r} @xref{Choosing a Style}.}, which makes a comment | |
3088 | ||
3089 | @example | |
3090 | /* Got O(n^2) here, which is a Bad Thing. */ | |
3091 | @end example | |
3092 | ||
3093 | @noindent | |
3094 | break into | |
3095 | ||
3096 | @example | |
3097 | @group | |
3098 | /* Got O(n^2) here, which | |
3099 | * is a Bad Thing. */ | |
3100 | @end group | |
3101 | @end example | |
3102 | ||
3103 | Note that it won't work to adjust the indentation by putting leading | |
3104 | spaces in @code{c-block-comment-prefix}, since @ccmode{} still uses the | |
3105 | normal indentation engine to indent the line. Thus, the right way to | |
3106 | fix the indentation is by customizing the @code{c} syntactic symbol. It | |
3107 | defaults to @code{c-lineup-C-comments}, which handles the indentation of | |
3108 | most common comment styles, see @ref{Line-Up Functions}. | |
3109 | @end defopt | |
3110 | ||
3111 | @defopt c-ignore-auto-fill | |
3112 | @vindex ignore-auto-fill (c-) | |
3113 | When auto fill mode is enabled, @ccmode{} can selectively ignore it | |
3114 | depending on the context the line break would occur in, e.g. to never | |
3115 | break a line automatically inside a string literal. This variable | |
3116 | takes a list of symbols for the different contexts where auto-filling | |
3117 | never should occur: | |
3118 | ||
3119 | @table @code | |
3120 | @item string | |
3121 | Inside a string or character literal. | |
3122 | @item c | |
3123 | Inside a C style block comment. | |
3124 | @item c++ | |
3125 | Inside a C++ style line comment. | |
3126 | @item cpp | |
3127 | Inside a preprocessor directive. | |
3128 | @item code | |
3129 | Anywhere else, i.e. in normal code. | |
3130 | @end table | |
3131 | ||
3132 | By default, @code{c-ignore-auto-fill} is set to @code{(string cpp | |
3133 | code)}, which means that when auto-fill mode is activated, | |
3134 | auto-filling only occurs in comments. In literals, it's often | |
3135 | desirable to have explicit control over newlines. In preprocessor | |
3136 | directives, the necessary @samp{\} escape character before the newline | |
3137 | is not automatically inserted, so an automatic line break would | |
3138 | produce invalid code. In normal code, line breaks are normally | |
3139 | dictated by some logical structure in the code rather than the last | |
3140 | whitespace character, so automatic line breaks there will produce poor | |
3141 | results in the current implementation. | |
3142 | @end defopt | |
3143 | ||
3144 | @vindex comment-multi-line | |
3145 | If inside a comment and @code{comment-multi-line} (@pxref{Auto Fill,,, | |
3146 | @emacsman{}, @emacsmantitle{}} is non-@code{nil}, the indentation and | |
3147 | line prefix are preserved. If inside a comment and | |
3148 | @code{comment-multi-line} is @code{nil}, a new comment of the same | |
3149 | type is started on the next line and indented as appropriate for | |
3150 | comments. | |
3151 | ||
3152 | Note that @ccmode{} sets @code{comment-multi-line} to @code{t} at | |
3153 | startup. The reason is that @kbd{M-j} could otherwise produce sequences | |
3154 | of single line block comments for texts that should logically be treated | |
3155 | as one comment, and the rest of the paragraph handling code | |
3156 | (e.g. @kbd{M-q} and @kbd{M-a}) can't cope with that, which would lead to | |
3157 | inconsistent behavior. | |
3158 | ||
3159 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3160 | @node Custom Auto-newlines, Clean-ups, Custom Filling and Breaking, Top | |
3161 | @comment node-name, next, previous, up | |
3162 | @chapter Customizing Auto-newlines | |
3163 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3164 | ||
3165 | @ccmode{} determines whether to insert auto-newlines in two basically | |
3166 | different ways, depending on the character just typed: | |
3167 | ||
3168 | @table @asis | |
3169 | @item Braces and Colons | |
3170 | @ccmode{} first determines the syntactic context of the brace or colon | |
3171 | (@pxref{Syntactic Symbols}), then looks for a corresponding element in | |
3172 | an alist. This element specifies where to put newlines - this is any | |
3173 | combination of before and after the brace or colon. If no alist | |
3174 | element is found, newlines are inserted both before and after a brace, | |
3175 | but none are inserted around a colon. See @ref{Hanging Braces} and | |
3176 | @ref{Hanging Colons}. | |
3177 | ||
3178 | @item Semicolons and Commas | |
3179 | The variable @code{c-hanging-semi&comma-criteria} contains a list of | |
3180 | functions which determine whether to insert a newline after a newly | |
3181 | typed semicolon or comma. @xref{Hanging Semicolons and Commas}. | |
3182 | @end table | |
3183 | ||
3184 | The names of these configuration variables contain @samp{hanging} | |
3185 | because they let you @dfn{hang} the pertinent characters. A character | |
3186 | which introduces a C construct is said to @dfn{hang on the right} when | |
3187 | it appears at the end of a line after other code, being separated by a | |
3188 | line break from the construct it introduces, like the opening brace in: | |
3189 | ||
3190 | @example | |
3191 | @group | |
3192 | while (i < MAX) @{ | |
3193 | total += entry[i]; | |
3194 | entry [i++] = 0; | |
3195 | @} | |
3196 | @end group | |
3197 | @end example | |
3198 | ||
3199 | @noindent | |
3200 | A character @dfn{hangs on the left} when it appears at the start of | |
3201 | the line after the construct it closes off, like the above closing | |
3202 | brace. | |
3203 | ||
3204 | The next chapter, ``Clean-ups'', describes how to configure @ccmode{} | |
3205 | to remove these automatically added newlines in certain specific | |
3206 | circumstances. @xref{Clean-ups}. | |
3207 | ||
3208 | @menu | |
3209 | * Hanging Braces:: | |
3210 | * Hanging Colons:: | |
3211 | * Hanging Semicolons and Commas:: | |
3212 | @end menu | |
3213 | ||
3214 | ||
3215 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3216 | @node Hanging Braces, Hanging Colons, Custom Auto-newlines, Custom Auto-newlines | |
3217 | @comment node-name, next, previous, up | |
3218 | @section Hanging Braces | |
3219 | @cindex hanging braces | |
3220 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3221 | ||
3222 | To specify which kinds of braces you want auto-newlines put around, | |
3223 | you set the style variable @code{c-hanging-braces-alist}. Its | |
3224 | structure and semantics are described in this section. Details of how | |
3225 | to set it up, and its relationship to CC Mode's style system are given | |
3226 | in @ref{Style Variables}. | |
3227 | ||
3228 | Say you wanted an auto-newline after (but not before) the following | |
3229 | @samp{@{}: | |
3230 | ||
3231 | @example | |
3232 | if (foo < 17) @{ | |
3233 | @end example | |
3234 | ||
3235 | @noindent | |
3236 | First you need to find the @dfn{syntactic context} of the brace---type | |
3237 | a @key{RET} before the brace to get it on a line of its | |
3238 | own@footnote{Also insert a @samp{\} at the end of the previous line if | |
3239 | you're in AWK Mode.}, then type @kbd{C-c C-s}. That will tell you | |
3240 | something like: | |
3241 | ||
3242 | @example | |
3243 | ((substatement-open 1061)) | |
3244 | @end example | |
3245 | ||
3246 | @noindent | |
3247 | So here you need to put the entry @code{(substatement-open . (after))} | |
3248 | into @code{c-hanging-braces-alist}. | |
3249 | ||
3250 | If you don't want any auto-newlines for a particular syntactic symbol, | |
3251 | put this into @code{c-hanging-braces-alist}: | |
3252 | ||
3253 | @example | |
3254 | (brace-entry-open) | |
3255 | @end example | |
3256 | ||
3257 | If some brace syntactic symbol is not in @code{c-hanging-brace-alist}, | |
3258 | its entry is taken by default as @code{(before after)}---insert a | |
3259 | newline both before and after the brace. In place of a | |
3260 | ``before/after'' list you can specify a function in this alist---this | |
3261 | is useful when the auto newlines depend on the code around the brace. | |
3262 | ||
3263 | @defopt c-hanging-braces-alist | |
3264 | @vindex hanging-braces-alist (c-) | |
3265 | ||
3266 | This variable is an association list which maps syntactic symbols to | |
3267 | lists of places to insert a newline. @xref{Association | |
3268 | Lists,,,@lispref{}, @lispreftitle{}}. The key of each element is the | |
3269 | syntactic symbol, the associated value is either @code{nil}, a list, | |
3270 | or a function. | |
3271 | ||
3272 | @table @asis | |
3273 | @item The Key - the syntactic symbol | |
3274 | The syntactic symbols that are useful as keys in this list are | |
3275 | @code{brace-list-intro}, @code{statement-cont}, | |
3276 | @code{inexpr-class-open}, @code{inexpr-class-close}, and all the | |
3277 | @code{*-open} and @code{*-close} symbols. @xref{Syntactic Symbols}, | |
3278 | for a more detailed description of these syntactic symbols, except for | |
3279 | @code{inexpr-class-open} and @code{inexpr-class-close}, which aren't | |
3280 | actual syntactic symbols. Elements with any other value as a key get | |
3281 | ignored. | |
3282 | ||
3283 | The braces of anonymous inner classes in Java are given the special | |
3284 | symbols @code{inexpr-class-open} and @code{inexpr-class-close}, so that | |
3285 | they can be distinguished from the braces of normal classes@footnote{The | |
3286 | braces of anonymous classes produce a combination of | |
3287 | @code{inexpr-class}, and @code{class-open} or @code{class-close} in | |
3288 | normal indentation analysis.}. | |
3289 | ||
3290 | Note that the aggregate constructs in Pike mode, @samp{(@{}, @samp{@})}, | |
3291 | @samp{([}, @samp{])}, and @samp{(<}, @samp{>)}, do not count as brace | |
3292 | lists in this regard, even though they do for normal indentation | |
3293 | purposes. It's currently not possible to set automatic newlines on | |
3294 | these constructs. | |
3295 | ||
3296 | @item The associated value - the ``ACTION'' list or function | |
3297 | The value associated with each syntactic symbol in this association | |
3298 | list is called an @var{action}, which can be either a list or a | |
3299 | function which returns a list. @xref{Custom Braces}, for how to use | |
3300 | a function as a brace hanging @var{action}. | |
3301 | ||
3302 | The list @var{action} (or the list returned by @var{action} when it's | |
3303 | a function) contains some combination of the symbols @code{before} and | |
3304 | @code{after}, directing @ccmode{} where to put newlines in | |
3305 | relationship to the brace being inserted. Thus, if the list contains | |
3306 | only the symbol @code{after}, then the brace hangs on the right side | |
3307 | of the line, as in: | |
3308 | ||
3309 | @example | |
3310 | // here, open braces always `hang' | |
3311 | void spam( int i ) @{ | |
3312 | if( i == 7 ) @{ | |
3313 | dosomething(i); | |
3314 | @} | |
3315 | @} | |
3316 | @end example | |
3317 | ||
3318 | When the list contains both @code{after} and @code{before}, the braces | |
3319 | will appear on a line by themselves, as shown by the close braces in | |
3320 | the above example. The list can also be empty, in which case newlines | |
3321 | are added neither before nor after the brace. | |
3322 | @end table | |
3323 | ||
3324 | If a syntactic symbol is missing entirely from | |
3325 | @code{c-hanging-braces-alist}, it's treated in the same way as an | |
3326 | @var{action} with a list containing @code{before} and @code{after}, so | |
3327 | that braces by default end up on their own line. | |
3328 | ||
3329 | For example, the default value of @code{c-hanging-braces-alist} is: | |
3330 | ||
3331 | @example | |
3332 | ((brace-list-open) | |
3333 | (brace-entry-open) | |
3334 | (statement-cont) | |
3335 | (substatement-open after) | |
3336 | (block-close . c-snug-do-while) | |
3337 | (extern-lang-open after) | |
3338 | (namespace-open after) | |
3339 | (module-open after) | |
3340 | (composition-open after) | |
3341 | (inexpr-class-open after) | |
3342 | (inexpr-class-close before)) | |
3343 | @end example | |
3344 | ||
3345 | @noindent which says that @code{brace-list-open}, | |
3346 | @code{brace-entry-open} and @code{statement-cont}@footnote{Brace lists | |
3347 | inside statements, such as initializers for static array variables | |
3348 | inside functions in C, are recognized as @code{statement-cont}. All | |
3349 | normal substatement blocks are recognized with other symbols.} braces | |
3350 | should both hang on the right side and allow subsequent text to follow | |
3351 | on the same line as the brace. Also, @code{substatement-open}, | |
3352 | @code{extern-lang-open}, and @code{inexpr-class-open} braces should hang | |
3353 | on the right side, but subsequent text should follow on the next line. | |
3354 | The opposite holds for @code{inexpr-class-close} braces; they won't | |
3355 | hang, but the following text continues on the same line. Here, in the | |
3356 | @code{block-close} entry, you also see an example of using a function as | |
3357 | an @var{action}. In all other cases, braces are put on a line by | |
3358 | themselves. | |
3359 | @end defopt | |
3360 | ||
3361 | @menu | |
3362 | * Custom Braces:: | |
3363 | @end menu | |
3364 | ||
3365 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3366 | @node Custom Braces, , Hanging Braces, Hanging Braces | |
3367 | @comment node-name, next, previous, up | |
3368 | @subsection Custom Brace Hanging | |
3369 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3370 | ||
3371 | @vindex c-hanging-braces-alist | |
3372 | @vindex hanging-braces-alist (c-) | |
3373 | @cindex action functions | |
3374 | Syntactic symbols aren't the only place where you can customize | |
3375 | @ccmode{} with the lisp equivalent of callback functions. Remember | |
3376 | that @var{action}s are usually a list containing some combination of | |
3377 | the symbols @code{before} and @code{after} (@pxref{Hanging Braces}). | |
3378 | For more flexibility, you can instead specify brace ``hanginess'' by | |
3379 | giving a syntactic symbol an @dfn{action function} in | |
3380 | @code{c-hanging-braces-alist}; this function determines the | |
3381 | ``hanginess'' of a brace, usually by looking at the code near it. | |
3382 | ||
3383 | @cindex customization, brace hanging | |
3384 | An action function is called with two arguments: the syntactic symbol | |
3385 | for the brace (e.g. @code{substatement-open}), and the buffer position | |
3386 | where the brace has been inserted. Point is undefined on entry to an | |
3387 | action function, but the function must preserve it (e.g. by using | |
3388 | @code{save-excursion}). The return value should be a list containing | |
3389 | some combination of @code{before} and @code{after}, including neither | |
3390 | of them (i.e. @code{nil}). | |
3391 | ||
3392 | @defvar c-syntactic-context | |
3393 | @vindex syntactic-context (c-) | |
3394 | During the call to the indentation or brace hanging @var{action} | |
3395 | function, this variable is bound to the full syntactic analysis list. | |
3396 | This might be, for example, @samp{((block-close 73))}. Don't ever | |
3397 | give @code{c-syntactic-context} a value yourself---this would disrupt | |
3398 | the proper functioning of @ccmode{}. | |
3399 | ||
3400 | This variable is also bound in three other circumstances: | |
3401 | (i)@w{ }when calling a c-hanging-semi&comma-criteria function | |
3402 | (@pxref{Hanging Semicolons and Commas}); (ii)@w{ }when calling a | |
3403 | line-up function (@pxref{Custom Line-Up}); (iii)@w{ }when calling a | |
3404 | c-special-indent-hook function (@pxref{Other Indentation}). | |
3405 | @end defvar | |
3406 | ||
3407 | As an example, @ccmode{} itself uses this feature to dynamically | |
3408 | determine the hanginess of braces which close ``do-while'' | |
3409 | constructs: | |
3410 | ||
3411 | @example | |
3412 | void do_list( int count, char** atleast_one_string ) | |
3413 | @{ | |
3414 | int i=0; | |
3415 | do @{ | |
3416 | handle_string( atleast_one_string[i] ); | |
3417 | i++; | |
3418 | @} while( i < count ); | |
3419 | @} | |
3420 | @end example | |
3421 | ||
3422 | @ccmode{} assigns the @code{block-close} syntactic symbol to the | |
3423 | brace that closes the @code{do} construct, and normally we'd like the | |
3424 | line that follows a @code{block-close} brace to begin on a separate | |
3425 | line. However, with ``do-while'' constructs, we want the | |
3426 | @code{while} clause to follow the closing brace. To do this, we | |
3427 | associate the @code{block-close} symbol with the @var{action} function | |
3428 | @code{c-snug-do-while}: | |
3429 | ||
3430 | @example | |
3431 | (defun c-snug-do-while (syntax pos) | |
3432 | "Dynamically calculate brace hanginess for do-while statements." | |
3433 | (save-excursion | |
3434 | (let (langelem) | |
3435 | (if (and (eq syntax 'block-close) | |
3436 | (setq langelem (assq 'block-close c-syntactic-context)) | |
3437 | (progn (goto-char (cdr langelem)) | |
3438 | (if (= (following-char) ?@{) | |
3439 | (forward-sexp -1)) | |
3440 | (looking-at "\\<do\\>[^_]"))) | |
3441 | '(before) | |
3442 | '(before after))))) | |
3443 | @end example | |
3444 | ||
3445 | @findex c-snug-do-while | |
3446 | @findex snug-do-while (c-) | |
3447 | This function simply looks to see if the brace closes a ``do-while'' | |
3448 | clause and if so, returns the list @samp{(before)} indicating | |
3449 | that a newline should be inserted before the brace, but not after it. | |
3450 | In all other cases, it returns the list @samp{(before after)} so | |
3451 | that the brace appears on a line by itself. | |
3452 | ||
3453 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3454 | @node Hanging Colons, Hanging Semicolons and Commas, Hanging Braces, Custom Auto-newlines | |
3455 | @comment node-name, next, previous, up | |
3456 | @section Hanging Colons | |
3457 | @cindex hanging colons | |
3458 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3459 | ||
3460 | @cindex customization, colon hanging | |
3461 | @vindex c-hanging-colons-alist | |
3462 | @vindex hanging-colons-alist (c-) | |
3463 | ||
3464 | Using a mechanism similar to brace hanging (@pxref{Hanging Braces}), | |
3465 | colons can also be made to hang using the style variable | |
3466 | @code{c-hanging-colons-alist} - When a colon is typed, @ccmode | |
3467 | determines its syntactic context, looks this up in the alist | |
3468 | @code{c-changing-colons-alist} and inserts up to two newlines | |
3469 | accordingly. Here, however, If @ccmode fails to find an entry for a | |
3470 | syntactic symbol in the alist, no newlines are inserted around the | |
3471 | newly typed colon. | |
3472 | ||
3473 | @defopt c-hanging-colons-alist | |
3474 | @vindex hanging-colons-alist (c-) | |
3475 | ||
3476 | @table @asis | |
3477 | @item The Key - the syntactic symbol | |
3478 | The syntactic symbols appropriate as keys in this association list | |
3479 | are: @code{case-label}, @code{label}, @code{access-label}, | |
3480 | @code{member-init-intro}, and @code{inher-intro}. @xref{Syntactic | |
3481 | Symbols}. Elements with any other value as a key get ignored. | |
3482 | ||
3483 | @item The associate value - the ``ACTION'' list | |
3484 | The @var{action} here is simply a list containing a combination of the | |
3485 | symbols @code{before} and @code{after}. Unlike in | |
3486 | @code{c-hanging-braces-alist}, functions as @var{actions} are not | |
3487 | supported - there doesn't seem to be any need for them. | |
3488 | @end table | |
3489 | @end defopt | |
3490 | ||
3491 | In C++, double-colons are used as a scope operator but because these | |
3492 | colons always appear right next to each other, newlines before and after | |
3493 | them are controlled by a different mechanism, called @dfn{clean-ups} in | |
3494 | @ccmode{}. @xref{Clean-ups}, for details. | |
3495 | ||
3496 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3497 | @node Hanging Semicolons and Commas, , Hanging Colons, Custom Auto-newlines | |
3498 | @comment node-name, next, previous, up | |
3499 | @section Hanging Semicolons and Commas | |
3500 | @cindex hanging semicolons | |
3501 | @cindex hanging commas | |
3502 | @cindex customization, semicolon newlines | |
3503 | @cindex customization, comma newlines | |
3504 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3505 | ||
3506 | @defopt c-hanging-semi&comma-criteria | |
3507 | @vindex hanging-semi&comma-criteria (c-) | |
3508 | This style variable takes a list of functions; these get called when | |
3509 | you type a semicolon or comma. The functions are called in order | |
3510 | without arguments. When these functions are entered, point is just | |
3511 | after the newly inserted @samp{;} or @samp{,} and they must preserve | |
3512 | point (e.g., by using @code{save-excursion}). During the call, the | |
3513 | variable @code{c-syntactic-context} is bound to the syntactic context | |
3514 | of the current line@footnote{This was first introduced in @ccmode{} | |
3515 | 5.31.} @pxref{Custom Braces}. These functions don't insert newlines | |
3516 | themselves, rather they direct @ccmode{} whether or not to do so. | |
3517 | They should return one of the following values: | |
3518 | ||
3519 | @table @code | |
3520 | @item t | |
3521 | A newline is to be inserted after the @samp{;} or @samp{,}, and no | |
3522 | more functions from the list are to be called. | |
3523 | @item stop | |
3524 | No more functions from the list are to be called, and no newline is to | |
3525 | be inserted. | |
3526 | @item nil | |
3527 | No determination has been made, and the next function in the list is | |
3528 | to be called. | |
3529 | @end table | |
3530 | ||
3531 | Note that auto-newlines are never inserted @emph{before} a semicolon | |
3532 | or comma. If every function in the list is called without a | |
3533 | determination being made, then no newline is added. | |
3534 | ||
3535 | In AWK mode, this variable is set by default to @code{nil}. In the | |
3536 | other modes, the default value is a list containing a single function, | |
3537 | @code{c-semi&comma-inside-parenlist}. This inserts newlines after all | |
3538 | semicolons, apart from those separating @code{for}-clause statements. | |
3539 | @end defopt | |
3540 | ||
3541 | @defun c-semi&comma-no-newlines-before-nonblanks | |
3542 | @findex semi&comma-no-newlines-before-nonblanks (c-) | |
3543 | This is an example of a criteria function, provided by @ccmode{}. It | |
3544 | prevents newlines from being inserted after semicolons when there is a | |
3545 | non-blank following line. Otherwise, it makes no determination. To | |
3546 | use, add this function to the front of the | |
3547 | @code{c-hanging-semi&comma-criteria} list. | |
3548 | ||
3549 | @example | |
3550 | (defun c-semi&comma-no-newlines-before-nonblanks () | |
3551 | (save-excursion | |
3552 | (if (and (eq last-command-char ?\;) | |
3553 | (zerop (forward-line 1)) | |
3554 | (not (looking-at "^[ \t]*$"))) | |
3555 | 'stop | |
3556 | nil))) | |
3557 | @end example | |
3558 | @end defun | |
3559 | ||
3560 | @defun c-semi&comma-inside-parenlist | |
3561 | @findex semi&comma-inside-parenlist (c-) | |
3562 | @defunx c-semi&comma-no-newlines-for-oneline-inliners | |
3563 | @findex semi&comma-no-newlines-for-oneline-inliners (c-) | |
3564 | The function @code{c-semi&comma-inside-parenlist} is what prevents | |
3565 | newlines from being inserted inside the parenthesis list of @code{for} | |
3566 | statements. In addition to | |
3567 | @code{c-semi&comma-no-newlines-before-nonblanks} described above, | |
3568 | @ccmode{} also comes with the criteria function | |
3569 | @code{c-semi&comma-no-newlines-for-oneline-inliners}, which suppresses | |
3570 | newlines after semicolons inside one-line inline method definitions | |
3571 | (e.g. in C++ or Java). | |
3572 | @end defun | |
3573 | ||
3574 | ||
3575 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3576 | @node Clean-ups, Indentation Engine Basics, Custom Auto-newlines, Top | |
3577 | @comment node-name, next, previous, up | |
3578 | @chapter Clean-ups | |
3579 | @cindex clean-ups | |
3580 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3581 | ||
3582 | @dfn{Clean-ups} are mechanisms which remove (or exceptionally, add) | |
3583 | whitespace in specific circumstances and are complementary to colon | |
3584 | and brace hanging. You enable a clean-up by adding its symbol into | |
3585 | @code{c-cleanup-list}, e.g. like this: | |
3586 | ||
3587 | @example | |
3588 | (add-to-list 'c-cleanup-list 'space-before-funcall) | |
3589 | @end example | |
3590 | ||
3591 | On the surface, it would seem that clean-ups overlap the functionality | |
3592 | provided by the @code{c-hanging-*-alist} variables. Clean-ups, | |
3593 | however, are used to adjust code ``after-the-fact'', i.e. to adjust | |
3594 | the whitespace in constructs later than when they were typed. | |
3595 | ||
3596 | Most of the clean-ups remove automatically inserted newlines, and are | |
3597 | only active when auto-newline minor mode is turned on. Others will | |
3598 | work all the time. Note that clean-ups are only performed when there | |
3599 | is nothing but whitespace appearing between the individual components | |
3600 | of the construct, and (apart from @code{comment-close-slash}) when the | |
3601 | construct does not occur within a literal (@pxref{Auto-newlines}). | |
3602 | ||
3603 | @defopt c-cleanup-list | |
3604 | @vindex cleanup-list (c-) | |
3605 | @cindex literal | |
3606 | ||
3607 | You configure @ccmode{}'s clean-ups by setting the style variable | |
3608 | @code{c-cleanup-list}, which is a list of clean-up symbols. By | |
3609 | default, @ccmode{} cleans up only the @code{scope-operator} construct, | |
3610 | which is necessary for proper C++ support. | |
3611 | @end defopt | |
3612 | ||
3613 | These are the clean-ups that are only active when electric and | |
3614 | auto-newline minor modes are enabled: | |
3615 | ||
3616 | @c TBD: Would like to use some sort of @deffoo here; @table indents a | |
3617 | @c bit too much in dvi output. | |
3618 | @table @code | |
3619 | @item brace-else-brace | |
3620 | Clean up @samp{@} else @{} constructs by placing the entire construct on | |
3621 | a single line. Clean up occurs when the open brace after the | |
3622 | @samp{else} is typed. So for example, this: | |
3623 | ||
3624 | @example | |
3625 | @group | |
3626 | void spam(int i) | |
3627 | @{ | |
3628 | if( i==7 ) @{ | |
3629 | dosomething(); | |
3630 | @} | |
3631 | else | |
3632 | @{ | |
3633 | @end group | |
3634 | @end example | |
3635 | ||
3636 | @noindent | |
3637 | appears like this after the last open brace is typed: | |
3638 | ||
3639 | @example | |
3640 | @group | |
3641 | void spam(int i) | |
3642 | @{ | |
3643 | if( i==7 ) @{ | |
3644 | dosomething(); | |
3645 | @} else @{ | |
3646 | @end group | |
3647 | @end example | |
3648 | ||
3649 | @item brace-elseif-brace | |
3650 | Similar to the @code{brace-else-brace} clean-up, but this cleans up | |
3651 | @samp{@} else if (...) @{} constructs. For example: | |
3652 | ||
3653 | @example | |
3654 | @group | |
3655 | void spam(int i) | |
3656 | @{ | |
3657 | if( i==7 ) @{ | |
3658 | dosomething(); | |
3659 | @} | |
3660 | else if( i==3 ) | |
3661 | @{ | |
3662 | @end group | |
3663 | @end example | |
3664 | ||
3665 | @noindent | |
3666 | appears like this after the last open parenthesis is typed: | |
3667 | ||
3668 | @example | |
3669 | @group | |
3670 | void spam(int i) | |
3671 | @{ | |
3672 | if( i==7 ) @{ | |
3673 | dosomething(); | |
3674 | @} else if( | |
3675 | @end group | |
3676 | @end example | |
3677 | ||
3678 | @noindent | |
3679 | and like this after the last open brace is typed: | |
3680 | ||
3681 | @example | |
3682 | @group | |
3683 | void spam(int i) | |
3684 | @{ | |
3685 | if( i==7 ) @{ | |
3686 | dosomething(); | |
3687 | @} else if( i==3 ) @{ | |
3688 | @end group | |
3689 | @end example | |
3690 | ||
3691 | @item brace-catch-brace | |
3692 | Analogous to @code{brace-elseif-brace}, but cleans up @samp{@} catch | |
3693 | (...) @{} in C++ and Java mode. | |
3694 | ||
3695 | @item empty-defun-braces | |
3696 | Clean up braces following a top-level function or class definition that | |
3697 | contains no body. Clean up occurs when the closing brace is typed. | |
3698 | Thus the following: | |
3699 | ||
3700 | @example | |
3701 | @group | |
3702 | class Spam | |
3703 | @{ | |
3704 | @} | |
3705 | @end group | |
3706 | @end example | |
3707 | ||
3708 | @noindent | |
3709 | is transformed into this when the close brace is typed: | |
3710 | ||
3711 | @example | |
3712 | @group | |
3713 | class Spam | |
3714 | @{@} | |
3715 | @end group | |
3716 | @end example | |
3717 | ||
3718 | @item defun-close-semi | |
3719 | Clean up the terminating semicolon on top-level function or class | |
3720 | definitions when they follow a close brace. Clean up occurs when the | |
3721 | semicolon is typed. So for example, the following: | |
3722 | ||
3723 | @example | |
3724 | @group | |
3725 | class Spam | |
3726 | @{ | |
3727 | ... | |
3728 | @} | |
3729 | ; | |
3730 | @end group | |
3731 | @end example | |
3732 | ||
3733 | @noindent | |
3734 | is transformed into this when the semicolon is typed: | |
3735 | ||
3736 | @example | |
3737 | @group | |
3738 | class Spam | |
3739 | @{ | |
3740 | ... | |
3741 | @}; | |
3742 | @end group | |
3743 | @end example | |
3744 | ||
3745 | @item list-close-comma | |
3746 | Clean up commas following braces in array and aggregate initializers. | |
3747 | Clean up occurs when the comma is typed. The space before the comma | |
3748 | is zapped just like the space before the semicolon in | |
3749 | @code{defun-close-semi}. | |
3750 | ||
3751 | @item scope-operator | |
3752 | Clean up double colons which might designate a C++ scope operator split | |
3753 | across multiple lines@footnote{Certain C++ constructs introduce | |
3754 | ambiguous situations, so @code{scope-operator} clean-ups might not | |
3755 | always be correct. This usually only occurs when scoped identifiers | |
3756 | appear in switch label tags.}. Clean up occurs when the second colon is | |
3757 | typed. You will always want @code{scope-operator} in the | |
3758 | @code{c-cleanup-list} when you are editing C++ code. | |
3759 | ||
3760 | @item one-liner-defun | |
3761 | Clean up a single line of code enclosed by defun braces by removing | |
3762 | the whitespace before and after the code. The clean-up happens when | |
3763 | the closing brace is typed. If the variable | |
3764 | @code{c-max-one-liner-length} is set, the cleanup is only done if the | |
3765 | resulting line would be no longer than the value of that variable. | |
3766 | ||
3767 | For example, consider this AWK code: | |
3768 | ||
3769 | @example | |
3770 | @group | |
3771 | BEGIN @{ | |
3772 | FS = "\t" # use <TAB> as a field separator | |
3773 | @} | |
3774 | @end group | |
3775 | @end example | |
3776 | ||
3777 | @noindent | |
3778 | It gets compacted to the following when the closing brace is typed: | |
3779 | ||
3780 | @example | |
3781 | @group | |
3782 | BEGIN @{FS = "\t"@} # use <TAB> as a field separator | |
3783 | @end group | |
3784 | @end example | |
3785 | ||
3786 | @defopt c-max-one-liner-length | |
3787 | @vindex max-one-liner-length (c-) | |
3788 | The maximum length of the resulting line for which the clean-up | |
3789 | @code{one-liner-defun} will be triggered. This length is that of the entire | |
3790 | line, including any leading whitespace and any trailing comment. Its | |
3791 | default value is 80. If the value is zero or @code{nil}, no limit | |
3792 | applies. | |
3793 | @end defopt | |
3794 | @end table | |
3795 | ||
3796 | The following clean-ups are always active when they occur on | |
3797 | @code{c-cleanup-list}, regardless of whether Electric minor mode or | |
3798 | Auto-newline minor mode are enabled: | |
3799 | ||
3800 | @table @code | |
3801 | @item space-before-funcall | |
3802 | Insert a space between the function name and the opening parenthesis | |
3803 | of a function call. This produces function calls in the style | |
3804 | mandated by the GNU coding standards, e.g. @samp{signal@w{ }(SIGINT, | |
3805 | SIG_IGN)} and @samp{abort@w{ }()}. Clean up occurs when the opening | |
3806 | parenthesis is typed. This clean-up should never be active in AWK | |
3807 | Mode, since such a space is syntactically invalid for user defined | |
3808 | functions. | |
3809 | ||
3810 | @item compact-empty-funcall | |
3811 | Clean up any space between the function name and the opening parenthesis | |
3812 | of a function call that has no arguments. This is typically used | |
3813 | together with @code{space-before-funcall} if you prefer the GNU function | |
3814 | call style for functions with arguments but think it looks ugly when | |
3815 | it's only an empty parenthesis pair. I.e. you will get @samp{signal | |
3816 | (SIGINT, SIG_IGN)}, but @samp{abort()}. Clean up occurs when the | |
3817 | closing parenthesis is typed. | |
3818 | ||
3819 | @item comment-close-slash | |
3820 | When inside a block comment, terminate the comment when you type a slash | |
3821 | at the beginning of a line (i.e. immediately after the comment prefix). | |
3822 | This clean-up removes whitespace preceding the slash and if needed, | |
3823 | inserts a star to complete the token @samp{*/}. Type @kbd{C-q /} in this | |
3824 | situation if you just want a literal @samp{/} inserted. | |
3825 | @end table | |
3826 | ||
3827 | ||
3828 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3829 | @node Indentation Engine Basics, Customizing Indentation, Clean-ups, Top | |
3830 | @comment node-name, next, previous, up | |
3831 | @chapter Indentation Engine Basics | |
3832 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3833 | ||
3834 | This chapter will briefly cover how @ccmode{} indents lines of code. | |
3835 | It is helpful to understand the indentation model being used so that | |
3836 | you will know how to customize @ccmode{} for your personal coding | |
3837 | style. All the details are in @ref{Customizing Indentation}. | |
3838 | ||
3839 | @ccmode{} has an indentation engine that provides a flexible and | |
3840 | general mechanism for customizing indentation. When @ccmode{} indents | |
3841 | a line of code, it separates its calculations into two steps: | |
3842 | ||
3843 | @enumerate | |
3844 | @item | |
3845 | @cindex syntactic symbol | |
3846 | @cindex anchor position | |
3847 | It analyzes the line to determine its @dfn{syntactic symbol(s)} (the | |
3848 | kind of language construct it's looking at) and its @dfn{anchor | |
3849 | position} (the position earlier in the file that @ccmode{} will indent | |
3850 | the line relative to). The anchor position might be the location of | |
3851 | an opening brace in the previous line, for example. @xref{Syntactic | |
3852 | Analysis}. | |
3853 | @item | |
3854 | @cindex offsets | |
3855 | @cindex indentation offset specifications | |
3856 | It looks up the syntactic symbol(s) in the configuration to get the | |
3857 | corresponding @dfn{offset(s)}. The symbol @code{+}, which means | |
3858 | ``indent this line one more level'' is a typical offset. @ccmode{} | |
3859 | then applies these offset(s) to the anchor position, giving the | |
3860 | indentation for the line. The different sorts of offsets are | |
3861 | described in @ref{c-offsets-alist}. | |
3862 | @end enumerate | |
3863 | ||
3864 | In exceptional circumstances, the syntax directed indentation | |
3865 | described here may be a nuisance rather than a help. You can disable | |
3866 | it by setting @code{c-syntactic-indentation} to @code{nil}. (To set | |
3867 | the variable interactively, @ref{Minor Modes}). | |
3868 | ||
3869 | @defopt c-syntactic-indentation | |
3870 | @vindex syntactic-indentation (c-) | |
3871 | When this is non-@code{nil} (which it is by default), the indentation | |
3872 | of code is done according to its syntactic structure. When it's | |
3873 | @code{nil}, every line is just indented to the same level as the | |
3874 | previous one, and @kbd{TAB} (@code{c-indent-command}) adjusts the | |
3875 | indentation in steps of @code{c-basic-offset}. The current style | |
3876 | (@pxref{Config Basics}) then has no effect on indentation, nor do any | |
3877 | of the variables associated with indentation, not even | |
3878 | @code{c-special-indent-hook}. | |
3879 | @end defopt | |
3880 | ||
3881 | @menu | |
3882 | * Syntactic Analysis:: | |
3883 | * Syntactic Symbols:: | |
3884 | * Indentation Calculation:: | |
3885 | @end menu | |
3886 | ||
3887 | ||
3888 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3889 | @node Syntactic Analysis, Syntactic Symbols, Indentation Engine Basics, Indentation Engine Basics | |
3890 | @comment node-name, next, previous, up | |
3891 | @section Syntactic Analysis | |
3892 | @cindex syntactic analysis | |
3893 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
3894 | ||
3895 | @cindex syntactic element | |
3896 | @cindex syntactic context | |
3897 | The first thing @ccmode{} does when indenting a line of code, is to | |
3898 | analyze the line, determining the @dfn{syntactic context} of the | |
3899 | (first) construct on that line. It's a list of @dfn{syntactic | |
3900 | elements}, where each syntactic element in turn is a list@footnote{In | |
3901 | @ccmode 5.28 and earlier, a syntactic element was a dotted pair; the | |
3902 | cons was the syntactic symbol and the cdr was the anchor position. | |
3903 | For compatibility's sake, the parameter passed to a line-up function | |
3904 | still has this dotted pair form (@pxref{Custom Line-Up}).} Here is a | |
3905 | brief and typical example: | |
3906 | ||
3907 | @example | |
3908 | ((defun-block-intro 1959)) | |
3909 | @end example | |
3910 | ||
3911 | @cindex syntactic symbol | |
3912 | @noindent | |
3913 | The first thing inside each syntactic element is always a | |
3914 | @dfn{syntactic symbol}. It describes the kind of construct that was | |
3915 | recognized, e.g. @code{statement}, @code{substatement}, | |
3916 | @code{class-open}, @code{class-close}, etc. @xref{Syntactic Symbols}, | |
3917 | for a complete list of currently recognized syntactic symbols and | |
3918 | their semantics. The remaining entries are various data associated | |
3919 | with the recognized construct - there might be zero or more. | |
3920 | ||
3921 | @cindex anchor position | |
3922 | Conceptually, a line of code is always indented relative to some | |
3923 | position higher up in the buffer (typically the indentation of the | |
3924 | previous line). That position is the @dfn{anchor position} in the | |
3925 | syntactic element. If there is an entry after the syntactic symbol in | |
3926 | the syntactic element list then it's either nil or that anchor position. | |
3927 | ||
3928 | Here is an example. Suppose we had the following code as the only thing | |
3929 | in a C++ buffer @footnote{The line numbers in this and future examples | |
3930 | don't actually appear in the buffer, of course!}: | |
3931 | ||
3932 | @example | |
3933 | 1: void swap( int& a, int& b ) | |
3934 | 2: @{ | |
3935 | 3: int tmp = a; | |
3936 | 4: a = b; | |
3937 | 5: b = tmp; | |
3938 | 6: @} | |
3939 | @end example | |
3940 | ||
3941 | @noindent | |
3942 | We can use @kbd{C-c C-s} (@code{c-show-syntactic-information}) to | |
3943 | report what the syntactic analysis is for the current line: | |
3944 | ||
3945 | @table @asis | |
3946 | @item @kbd{C-c C-s} (@code{c-show-syntactic-information}) | |
3947 | @kindex C-c C-s | |
3948 | @findex c-show-syntactic-information | |
3949 | @findex show-syntactic-information (c-) | |
3950 | This command calculates the syntactic analysis of the current line and | |
3951 | displays it in the minibuffer. The command also highlights the anchor | |
3952 | position(s). | |
3953 | @end table | |
3954 | ||
3955 | Running this command on line 4 of this example, we'd see in the echo | |
3956 | area@footnote{With a universal argument (i.e. @kbd{C-u C-c C-s}) the | |
3957 | analysis is inserted into the buffer as a comment on the current | |
3958 | line.}: | |
3959 | ||
3960 | @example | |
3961 | ((statement 35)) | |
3962 | @end example | |
3963 | ||
3964 | @noindent | |
3965 | and the @samp{i} of @code{int} on line 3 would be highlighted. This | |
3966 | tells us that the line is a statement and it is indented relative to | |
3967 | buffer position 35, the highlighted position. If you were to move | |
3968 | point to line 3 and hit @kbd{C-c C-s}, you would see: | |
3969 | ||
3970 | @example | |
3971 | ((defun-block-intro 29)) | |
3972 | @end example | |
3973 | ||
3974 | @noindent | |
3975 | This indicates that the @samp{int} line is the first statement in a top | |
3976 | level function block, and is indented relative to buffer position 29, | |
3977 | which is the brace just after the function header. | |
3978 | ||
3979 | Here's another example: | |
3980 | ||
3981 | @example | |
3982 | 1: int add( int val, int incr, int doit ) | |
3983 | 2: @{ | |
3984 | 3: if( doit ) | |
3985 | 4: @{ | |
3986 | 5: return( val + incr ); | |
3987 | 6: @} | |
3988 | 7: return( val ); | |
3989 | 8: @} | |
3990 | @end example | |
3991 | ||
3992 | @noindent | |
3993 | Hitting @kbd{C-c C-s} on line 4 gives us: | |
3994 | ||
3995 | @example | |
3996 | ((substatement-open 46)) | |
3997 | @end example | |
3998 | ||
3999 | @cindex substatement | |
4000 | @cindex substatement block | |
4001 | @noindent | |
4002 | which tells us that this is a brace that @emph{opens} a substatement | |
4003 | block. @footnote{A @dfn{substatement} is the line after a | |
4004 | conditional statement, such as @code{if}, @code{else}, @code{while}, | |
4005 | @code{do}, @code{switch}, etc. A @dfn{substatement | |
4006 | block} is a brace block following one of these conditional statements.} | |
4007 | ||
4008 | @cindex comment-only line | |
4009 | Syntactic contexts can contain more than one element, and syntactic | |
4010 | elements need not have anchor positions. The most common example of | |
4011 | this is a @dfn{comment-only line}: | |
4012 | ||
4013 | @example | |
4014 | 1: void draw_list( List<Drawables>& drawables ) | |
4015 | 2: @{ | |
4016 | 3: // call the virtual draw() method on each element in list | |
4017 | 4: for( int i=0; i < drawables.count(), ++i ) | |
4018 | 5: @{ | |
4019 | 6: drawables[i].draw(); | |
4020 | 7: @} | |
4021 | 8: @} | |
4022 | @end example | |
4023 | ||
4024 | @noindent | |
4025 | Hitting @kbd{C-c C-s} on line 3 of this example gives: | |
4026 | ||
4027 | @example | |
4028 | ((comment-intro) (defun-block-intro 46)) | |
4029 | @end example | |
4030 | ||
4031 | @noindent | |
4032 | and you can see that the syntactic context contains two syntactic | |
4033 | elements. Notice that the first element, @samp{(comment-intro)}, has no | |
4034 | anchor position. | |
4035 | ||
4036 | ||
4037 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4038 | @node Syntactic Symbols, Indentation Calculation, Syntactic Analysis, Indentation Engine Basics | |
4039 | @comment node-name, next, previous, up | |
4040 | @section Syntactic Symbols | |
4041 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4042 | ||
4043 | @cindex syntactic symbols, brief list | |
4044 | @vindex c-offsets-alist | |
4045 | @vindex offsets-alist (c-) | |
4046 | This section is a complete list of the syntactic symbols which appear | |
4047 | in the @code{c-offsets-alist} style variable, along with brief | |
4048 | descriptions. The previous section (@pxref{Syntactic Analysis}) | |
4049 | states what syntactic symbols are and how the indentation engine uses | |
4050 | them. | |
4051 | ||
4052 | More detailed descriptions of these symbols, together with snippets of | |
4053 | source code to which they apply, appear in the examples in the | |
4054 | subsections below. Note that, in the interests of brevity, the anchor | |
4055 | position associated with most syntactic symbols is @emph{not} | |
4056 | specified. In cases of doubt, type @kbd{C-c C-s} on a pertinent | |
4057 | line---this highlights the anchor position. | |
4058 | ||
4059 | @ssindex -open symbols | |
4060 | @ssindex -close symbols | |
4061 | @ssindex -block-intro symbols | |
4062 | The syntactic symbols which indicate brace constructs follow a general | |
4063 | naming convention. When a line begins with an open or close brace, | |
4064 | its syntactic symbol will contain the suffix @code{-open} or | |
4065 | @code{-close} respectively. The first line within the brace block | |
4066 | construct will contain the suffix @code{-block-intro}. | |
4067 | ||
4068 | @ssindex -intro symbols | |
4069 | @ssindex -cont symbols | |
4070 | In constructs which can span several lines, a distinction is usually | |
4071 | made between the first line that introduces the construct and the | |
4072 | lines that continue it. The syntactic symbols that indicate these | |
4073 | lines will contain the suffixes @code{-intro} or @code{-cont} | |
4074 | respectively. | |
4075 | ||
4076 | The best way to understand how all this works is by looking at some | |
4077 | examples. Remember that you can see the syntax of any source code | |
4078 | line by using @kbd{C-c C-s}. | |
4079 | ||
4080 | @table @code | |
4081 | @item string | |
4082 | Inside a multiline string. @ref{Literal Symbols}. | |
4083 | @item c | |
4084 | Inside a multiline C style block comment. @ref{Literal Symbols}. | |
4085 | @item defun-open | |
4086 | Brace that opens a top-level function definition. @ref{Function | |
4087 | Symbols}. | |
4088 | @item defun-close | |
4089 | Brace that closes a top-level function definition. @ref{Function | |
4090 | Symbols}. | |
4091 | @item defun-block-intro | |
4092 | The first line in a top-level defun. @ref{Function Symbols}. | |
4093 | @item class-open | |
4094 | Brace that opens a class definition. @ref{Class Symbols}. | |
4095 | @item class-close | |
4096 | Brace that closes a class definition. @ref{Class Symbols}. | |
4097 | @item inline-open | |
4098 | Brace that opens an in-class inline method. @ref{Class Symbols}. | |
4099 | @item inline-close | |
4100 | Brace that closes an in-class inline method. @ref{Class Symbols}. | |
4101 | @item func-decl-cont | |
4102 | The region between a function definition's argument list and the | |
4103 | function opening brace (excluding K&R argument declarations). In C, | |
4104 | you cannot put anything but whitespace and comments in this region, | |
4105 | however in C++ and Java, @code{throws} declarations and other things | |
4106 | can appear here. @ref{Literal Symbols}. @c @emph{FIXME!!! Can it not | |
4107 | @c go somewhere better?} | |
4108 | @item knr-argdecl-intro | |
4109 | First line of a K&R C argument declaration. @ref{K&R Symbols}. | |
4110 | @item knr-argdecl | |
4111 | Subsequent lines in a K&R C argument declaration. @ref{K&R Symbols}. | |
4112 | @item topmost-intro | |
4113 | The first line in a ``topmost'' definition. @ref{Function Symbols}. | |
4114 | @item topmost-intro-cont | |
4115 | Topmost definition continuation lines. This is only used in the parts | |
4116 | that aren't covered by other symbols such as @code{func-decl-cont} and | |
4117 | @code{knr-argdecl}. @ref{Function Symbols}. | |
5cee0a9c AM |
4118 | @item annotation-top-cont |
4119 | Topmost definition continuation lines where all previous items are | |
4120 | annotations. @ref{Java Symbols}. | |
4009494e GM |
4121 | @item member-init-intro |
4122 | First line in a member initialization list. @ref{Class Symbols}. | |
4123 | @item member-init-cont | |
4124 | Subsequent member initialization list lines. @ref{Class Symbols}. | |
4125 | @item inher-intro | |
4126 | First line of a multiple inheritance list. @ref{Class Symbols}. | |
4127 | @item inher-cont | |
4128 | Subsequent multiple inheritance lines. @ref{Class Symbols}. | |
4129 | @item block-open | |
4130 | Statement block open brace. @ref{Literal Symbols}. | |
4131 | @item block-close | |
4132 | Statement block close brace. @ref{Conditional Construct Symbols}. | |
4133 | @item brace-list-open | |
4134 | Open brace of an enum or static array list. @ref{Brace List Symbols}. | |
4135 | @item brace-list-close | |
4136 | Close brace of an enum or static array list. @ref{Brace List Symbols}. | |
4137 | @item brace-list-intro | |
4138 | First line in an enum or static array list. @ref{Brace List Symbols}. | |
4139 | @item brace-list-entry | |
4140 | Subsequent lines in an enum or static array list. @ref{Brace List | |
4141 | Symbols}. | |
4142 | @item brace-entry-open | |
4143 | Subsequent lines in an enum or static array list where the line begins | |
4144 | with an open brace. @ref{Brace List Symbols}. | |
4145 | @item statement | |
4146 | A statement. @ref{Function Symbols}. | |
4147 | @item statement-cont | |
4148 | A continuation of a statement. @ref{Function Symbols}. | |
5cee0a9c AM |
4149 | @item annotation-var-cont |
4150 | A continuation of a statement where all previous items are | |
4151 | annotations. @ref{Java Symbols}. | |
4009494e GM |
4152 | @item statement-block-intro |
4153 | The first line in a new statement block. @ref{Conditional Construct | |
4154 | Symbols}. | |
4155 | @item statement-case-intro | |
4156 | The first line in a case block. @ref{Switch Statement Symbols}. | |
4157 | @item statement-case-open | |
4158 | The first line in a case block that starts with a brace. @ref{Switch | |
4159 | Statement Symbols}. | |
4160 | @item substatement | |
4161 | The first line after a conditional or loop construct. | |
4162 | @ref{Conditional Construct Symbols}. | |
4163 | @item substatement-open | |
4164 | The brace that opens a substatement block. @ref{Conditional Construct | |
4165 | Symbols}. | |
4166 | @item substatement-label | |
4167 | The first line after a conditional or loop construct if it's a label. | |
4168 | @ref{Conditional Construct Symbols}. | |
4169 | @item case-label | |
4170 | A label in a @code{switch} block. @ref{Switch Statement Symbols}. | |
4171 | @item access-label | |
4172 | C++ access control label. @ref{Class Symbols}. | |
4173 | @item label | |
4174 | Any other label. @ref{Literal Symbols}. | |
4175 | @item do-while-closure | |
4176 | The @code{while} line that ends a @code{do}-@code{while} construct. | |
4177 | @ref{Conditional Construct Symbols}. | |
4178 | @item else-clause | |
4179 | The @code{else} line of an @code{if}-@code{else} construct. | |
4180 | @ref{Conditional Construct Symbols}. | |
4181 | @item catch-clause | |
4182 | The @code{catch} or @code{finally} (in Java) line of a | |
4183 | @code{try}-@code{catch} construct. @ref{Conditional Construct | |
4184 | Symbols}. | |
4185 | @item comment-intro | |
4186 | A line containing only a comment introduction. @ref{Literal Symbols}. | |
4187 | @item arglist-intro | |
4188 | The first line in an argument list. @ref{Paren List Symbols}. | |
4189 | @item arglist-cont | |
4190 | Subsequent argument list lines when no arguments follow on the same | |
4191 | line as the arglist opening paren. @ref{Paren List Symbols}. | |
4192 | @item arglist-cont-nonempty | |
4193 | Subsequent argument list lines when at least one argument follows on | |
4194 | the same line as the arglist opening paren. @ref{Paren List Symbols}. | |
4195 | @item arglist-close | |
4196 | The solo close paren of an argument list. @ref{Paren List Symbols}. | |
4197 | @item stream-op | |
4198 | Lines continuing a stream operator (C++ only). @ref{Literal | |
4199 | Symbols}. @c @emph{FIXME!!! Can this not be moved somewhere better?} | |
4200 | @item inclass | |
4201 | The line is nested inside a class definition. @ref{Class Symbols}. | |
4202 | @item cpp-macro | |
4203 | The start of a preprocessor macro definition. @ref{Literal Symbols}. | |
4204 | @item cpp-define-intro | |
4205 | The first line inside a multiline preprocessor macro if | |
4206 | @code{c-syntactic-indentation-in-macros} is set. @ref{Multiline Macro | |
4207 | Symbols}. | |
4208 | @item cpp-macro-cont | |
4209 | All lines inside multiline preprocessor macros if | |
4210 | @code{c-syntactic-indentation-in-macros} is @code{nil}. | |
4211 | @ref{Multiline Macro Symbols}. | |
4212 | @item friend | |
4213 | A C++ friend declaration. @ref{Class Symbols}. | |
4214 | @item objc-method-intro | |
4215 | The first line of an Objective-C method definition. @ref{Objective-C | |
4216 | Method Symbols}. | |
4217 | @item objc-method-args-cont | |
4218 | Lines continuing an Objective-C method definition. @ref{Objective-C | |
4219 | Method Symbols}. | |
4220 | @item objc-method-call-cont | |
4221 | Lines continuing an Objective-C method call. @ref{Objective-C Method | |
4222 | Symbols}. | |
4223 | @item extern-lang-open | |
4224 | Brace that opens an @code{extern} block (e.g. @code{extern "C" | |
4225 | @{...@}}). @ref{External Scope Symbols}. | |
4226 | @item extern-lang-close | |
4227 | Brace that closes an @code{extern} block. @ref{External Scope | |
4228 | Symbols}. | |
4229 | @item inextern-lang | |
4230 | Analogous to @code{inclass} syntactic symbol, but used inside | |
4231 | @code{extern} blocks. @ref{External Scope Symbols}. | |
4232 | @item namespace-open | |
4233 | @itemx namespace-close | |
4234 | @itemx innamespace | |
4235 | These are analogous to the three @code{extern-lang} symbols above, but | |
4236 | are returned for C++ namespace blocks. @ref{External Scope Symbols}. | |
4237 | @item module-open | |
4238 | @itemx module-close | |
4239 | @itemx inmodule | |
4240 | Analogous to the above, but for CORBA IDL @code{module} blocks. | |
4241 | @ref{External Scope Symbols}. | |
4242 | @item composition-open | |
4243 | @itemx composition-close | |
4244 | @itemx incomposition | |
4245 | Analogous to the above, but for CORBA CIDL @code{composition} blocks. | |
4246 | @ref{External Scope Symbols}. | |
4247 | @item template-args-cont | |
4248 | C++ template argument list continuations. @ref{Class Symbols}. | |
4249 | @item inlambda | |
4250 | Analogous to @code{inclass} syntactic symbol, but used inside lambda | |
4251 | (i.e. anonymous) functions. Only used in Pike mode. @ref{Statement | |
4252 | Block Symbols}. | |
4253 | @item lambda-intro-cont | |
4254 | Lines continuing the header of a lambda function, i.e. between the | |
4255 | @code{lambda} keyword and the function body. Only used in Pike mode. | |
4256 | @ref{Statement Block Symbols}. | |
4257 | @item inexpr-statement | |
4258 | A statement block inside an expression. The gcc C and C++ extension | |
4259 | for this is recognized. It's also used for the special functions that | |
4260 | take a statement block as an argument in Pike. @ref{Statement Block | |
4261 | Symbols}. | |
4262 | @item inexpr-class | |
4263 | A class definition inside an expression. This is used for anonymous | |
4264 | classes in Java. It's also used for anonymous array initializers in | |
5cee0a9c | 4265 | Java. @ref{Java Symbols}. |
4009494e GM |
4266 | @end table |
4267 | ||
4268 | @menu | |
91af3942 PE |
4269 | * Function Symbols:: |
4270 | * Class Symbols:: | |
4271 | * Conditional Construct Symbols:: | |
4272 | * Switch Statement Symbols:: | |
4273 | * Brace List Symbols:: | |
4274 | * External Scope Symbols:: | |
4275 | * Paren List Symbols:: | |
4276 | * Literal Symbols:: | |
4277 | * Multiline Macro Symbols:: | |
4278 | * Objective-C Method Symbols:: | |
5cee0a9c | 4279 | * Java Symbols:: |
91af3942 PE |
4280 | * Statement Block Symbols:: |
4281 | * K&R Symbols:: | |
4009494e GM |
4282 | @end menu |
4283 | ||
4284 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4285 | @node Function Symbols, Class Symbols, Syntactic Symbols, Syntactic Symbols | |
4286 | @comment node-name, next, previous, up | |
4287 | @subsection Function Symbols | |
4288 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4289 | ||
4290 | This example shows a typical function declaration. | |
4291 | ||
4292 | @example | |
4293 | 1: void | |
4294 | 2: swap( int& a, int& b ) | |
4295 | 3: @{ | |
4296 | 4: int tmp = a; | |
4297 | 5: a = b; | |
4298 | 6: b = tmp; | |
4299 | 7: int ignored = | |
4300 | 8: a + b; | |
4301 | 9: @} | |
4302 | @end example | |
4303 | ||
4304 | @ssindex topmost-intro | |
4305 | @ssindex topmost-intro-cont | |
4306 | @ssindex defun-open | |
4307 | @ssindex defun-close | |
4308 | @ssindex defun-block-intro | |
4309 | Line 1 shows a @code{topmost-intro} since it is the first line that | |
4310 | introduces a top-level construct. Line 2 is a continuation of the | |
4311 | top-level construct introduction so it has the syntax | |
4312 | @code{topmost-intro-cont}. Line 3 shows a @code{defun-open} since it is | |
4313 | the brace that opens a top-level function definition. Line 9 is the | |
4314 | corresponding | |
4315 | @code{defun-close} since it contains the brace that closes the top-level | |
4316 | function definition. Line 4 is a @code{defun-block-intro}, i.e. it is | |
4317 | the first line of a brace-block, enclosed in a | |
4318 | top-level function definition. | |
4319 | ||
4320 | @ssindex statement | |
4321 | @ssindex statement-cont | |
4322 | Lines 5, 6, and 7 are all given @code{statement} syntax since there | |
4323 | isn't much special about them. Note however that line 8 is given | |
4324 | @code{statement-cont} syntax since it continues the statement begun | |
4325 | on the previous line. | |
4326 | ||
4327 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4328 | @node Class Symbols, Conditional Construct Symbols, Function Symbols, Syntactic Symbols | |
4329 | @comment node-name, next, previous, up | |
4330 | @subsection Class related Symbols | |
4331 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4332 | ||
4333 | Here's an example which illustrates some C++ class syntactic symbols: | |
4334 | ||
4335 | @example | |
4336 | 1: class Bass | |
4337 | 2: : public Guitar, | |
4338 | 3: public Amplifiable | |
4339 | 4: @{ | |
4340 | 5: public: | |
4341 | 6: Bass() | |
4342 | 7: : eString( new BassString( 0.105 )), | |
4343 | 8: aString( new BassString( 0.085 )), | |
4344 | 9: dString( new BassString( 0.065 )), | |
4345 | 10: gString( new BassString( 0.045 )) | |
4346 | 11: @{ | |
4347 | 12: eString.tune( 'E' ); | |
4348 | 13: aString.tune( 'A' ); | |
4349 | 14: dString.tune( 'D' ); | |
4350 | 15: gString.tune( 'G' ); | |
4351 | 16: @} | |
4352 | 17: friend class Luthier; | |
4353 | 18: @}; | |
4354 | @end example | |
4355 | ||
4356 | @ssindex class-open | |
4357 | @ssindex class-close | |
4358 | As in the previous example, line 1 has the @code{topmost-intro} syntax. | |
4359 | Here however, the brace that opens a C++ class definition on line 4 is | |
4360 | assigned the @code{class-open} syntax. Note that in C++, classes, | |
4361 | structs, and unions are essentially equivalent syntactically (and are | |
4362 | very similar semantically), so replacing the @code{class} keyword in the | |
4363 | example above with @code{struct} or @code{union} would still result in a | |
4364 | syntax of @code{class-open} for line 4 @footnote{This is the case even | |
4365 | for C and Objective-C. For consistency, structs in all supported | |
4366 | languages are syntactically equivalent to classes. Note however that | |
4367 | the keyword @code{class} is meaningless in C and Objective-C.}. | |
4368 | Similarly, line 18 is assigned @code{class-close} syntax. | |
4369 | ||
4370 | @ssindex inher-intro | |
4371 | @ssindex inher-cont | |
4372 | Line 2 introduces the inheritance list for the class so it is assigned | |
4373 | the @code{inher-intro} syntax, and line 3, which continues the | |
4374 | inheritance list is given @code{inher-cont} syntax. | |
4375 | ||
4376 | @ssindex access-label | |
4377 | @ssindex inclass | |
4378 | Hitting @kbd{C-c C-s} on line 5 shows the following analysis: | |
4379 | ||
4380 | @example | |
4381 | ((inclass 58) (access-label 58)) | |
4382 | @end example | |
4383 | ||
4384 | @noindent | |
4385 | The primary syntactic symbol for this line is @code{access-label} as | |
5cee0a9c | 4386 | this is a label keyword that specifies access protection in C++. However, |
4009494e GM |
4387 | because this line is also a top-level construct inside a class |
4388 | definition, the analysis actually shows two syntactic symbols. The | |
4389 | other syntactic symbol assigned to this line is @code{inclass}. | |
4390 | Similarly, line 6 is given both @code{inclass} and @code{topmost-intro} | |
4391 | syntax: | |
4392 | ||
4393 | @example | |
4394 | ((inclass 58) (topmost-intro 60)) | |
4395 | @end example | |
4396 | ||
4397 | @ssindex member-init-intro | |
4398 | @ssindex member-init-cont | |
4399 | Line 7 introduces a C++ member initialization list and as such is given | |
4400 | @code{member-init-intro} syntax. Note that in this case it is | |
4401 | @emph{not} assigned @code{inclass} since this is not considered a | |
4402 | top-level construct. Lines 8 through 10 are all assigned | |
4403 | @code{member-init-cont} since they continue the member initialization | |
4404 | list started on line 7. | |
4405 | ||
4406 | @cindex in-class inline methods | |
4407 | @ssindex inline-open | |
4408 | @ssindex inline-close | |
4409 | Line 11's analysis is a bit more complicated: | |
4410 | ||
4411 | @example | |
4412 | ((inclass 58) (inline-open)) | |
4413 | @end example | |
4414 | ||
4415 | This line is assigned a syntax of both @code{inline-open} and | |
4416 | @code{inclass} because it opens an @dfn{in-class} C++ inline method | |
4417 | definition. This is distinct from, but related to, the C++ notion of an | |
4418 | inline function in that its definition occurs inside an enclosing class | |
4419 | definition, which in C++ implies that the function should be inlined. | |
4420 | However, if the definition of the @code{Bass} constructor appeared | |
4421 | outside the class definition, the construct would be given the | |
4422 | @code{defun-open} syntax, even if the keyword @code{inline} appeared | |
4423 | before the method name, as in: | |
4424 | ||
4425 | @example | |
4426 | 1: class Bass | |
4427 | 2: : public Guitar, | |
4428 | 3: public Amplifiable | |
4429 | 4: @{ | |
4430 | 5: public: | |
4431 | 6: Bass(); | |
4432 | 7: @}; | |
4433 | 8: | |
4434 | 9: inline | |
4435 | 10: Bass::Bass() | |
4436 | 11: : eString( new BassString( 0.105 )), | |
4437 | 12: aString( new BassString( 0.085 )), | |
4438 | 13: dString( new BassString( 0.065 )), | |
4439 | 14: gString( new BassString( 0.045 )) | |
4440 | 15: @{ | |
4441 | 16: eString.tune( 'E' ); | |
4442 | 17: aString.tune( 'A' ); | |
4443 | 18: dString.tune( 'D' ); | |
4444 | 19: gString.tune( 'G' ); | |
4445 | 20: @} | |
4446 | @end example | |
4447 | ||
4448 | @ssindex friend | |
4449 | Returning to the previous example, line 16 is given @code{inline-close} | |
4450 | syntax, while line 12 is given @code{defun-block-open} syntax, and lines | |
4451 | 13 through 15 are all given @code{statement} syntax. Line 17 is | |
4452 | interesting in that its syntactic analysis list contains three | |
4453 | elements: | |
4454 | ||
4455 | @example | |
4456 | ((inclass 58) (topmost-intro 380) (friend)) | |
4457 | @end example | |
4458 | ||
4459 | The @code{friend} and @code{inline-open} syntactic symbols are | |
4460 | modifiers that do not have anchor positions. | |
4461 | ||
4462 | @ssindex template-args-cont | |
4463 | Template definitions introduce yet another syntactic symbol: | |
4464 | ||
4465 | @example | |
4466 | 1: ThingManager <int, | |
4467 | 2: Framework::Callback *, | |
4468 | 3: Mutex> framework_callbacks; | |
4469 | @end example | |
4470 | ||
4471 | Here, line 1 is analyzed as a @code{topmost-intro}, but lines 2 and 3 | |
4472 | are both analyzed as @code{template-args-cont} lines. | |
4473 | ||
4474 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4475 | @node Conditional Construct Symbols, Switch Statement Symbols, Class Symbols, Syntactic Symbols | |
4476 | @comment node-name, next, previous, up | |
4477 | @subsection Conditional Construct Symbols | |
4478 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4479 | ||
4480 | Here is a (totally contrived) example which illustrates how syntax is | |
4481 | assigned to various conditional constructs: | |
4482 | ||
4483 | @example | |
4484 | 1: void spam( int index ) | |
4485 | 2: @{ | |
4486 | 3: for( int i=0; i<index; i++ ) | |
4487 | 4: @{ | |
4488 | 5: if( i == 10 ) | |
4489 | 6: do_something_special(); | |
4490 | 7: else | |
4491 | 8: silly_label: | |
4492 | 9: do_something( i ); | |
4493 | 10: @} | |
4494 | 11: do @{ | |
4495 | 12: another_thing( i-- ); | |
4496 | 13: @} | |
4497 | 14: while( i > 0 ); | |
4498 | 15: @} | |
4499 | @end example | |
4500 | ||
4501 | Only the lines that illustrate new syntactic symbols will be discussed. | |
4502 | ||
4503 | @ssindex substatement-open | |
4504 | @ssindex statement-block-intro | |
4505 | @ssindex block-close | |
4506 | Line 4 has a brace which opens a conditional's substatement block. It | |
4507 | is thus assigned @code{substatement-open} syntax, and since line 5 is | |
4508 | the first line in the substatement block, it is assigned | |
4509 | @code{statement-block-intro} syntax. Line 10 contains the brace | |
4510 | that closes the inner substatement block, and is therefore given the | |
4511 | syntax @code{block-close}@footnote{@code{block-open} is used only for | |
4512 | ``free-standing'' blocks, and is somewhat rare (@pxref{Literal | |
4513 | Symbols} for an example.)}. Line 13 is treated the same way. | |
4514 | ||
4515 | @ssindex substatement | |
4516 | Lines 6 and 9 are also substatements of conditionals, but since they | |
4517 | don't start blocks they are given @code{substatement} syntax | |
4518 | instead of @code{substatement-open}. | |
4519 | ||
4520 | @ssindex substatement-label | |
4521 | Line 8 contains a label, which is normally given @code{label} syntax. | |
4522 | This one is however a bit special since it's between a conditional and | |
4523 | its substatement. It's analyzed as @code{substatement-label} to let you | |
4524 | handle this rather odd case differently from normal labels. | |
4525 | ||
4526 | @ssindex else-clause | |
4527 | @ssindex catch-clause | |
4528 | Line 7 start with an @code{else} that matches the @code{if} statement on | |
4529 | line 5. It is therefore given the @code{else-clause} syntax and is | |
4530 | anchored on the matching @code{if}. The @code{try}-@code{catch} | |
4531 | constructs in C++ and Java are treated this way too, except that | |
4532 | @code{catch} and (in Java) @code{finally}, are marked with | |
4533 | @code{catch-clause}. | |
4534 | ||
4535 | @ssindex do-while-closure | |
4536 | The @code{while} construct on line 14 that closes a @code{do} | |
4537 | conditional is given the special syntax @code{do-while-closure} if it | |
4538 | appears on a line by itself. Note that if the @code{while} appeared on | |
4539 | the same line as the preceding close brace, that line would still have | |
4540 | @code{block-close} syntax. | |
4541 | ||
4542 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4543 | @node Switch Statement Symbols, Brace List Symbols, Conditional Construct Symbols, Syntactic Symbols | |
4544 | @comment node-name, next, previous, up | |
4545 | @subsection Switch Statement Symbols | |
4546 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4547 | ||
4548 | Switch statements have their own set of syntactic symbols. Here's an | |
4549 | example: | |
4550 | ||
4551 | @example | |
4552 | 1: void spam( enum Ingredient i ) | |
4553 | 2: @{ | |
4554 | 3: switch( i ) @{ | |
4555 | 4: case Ham: | |
4556 | 5: be_a_pig(); | |
4557 | 6: break; | |
4558 | 7: case Salt: | |
4559 | 8: drink_some_water(); | |
4560 | 9: break; | |
4561 | 10: default: | |
4562 | 11: @{ | |
4563 | 12: what_is_it(); | |
4564 | 13: break; | |
4565 | 14: @} | |
4566 | 15: @} | |
4567 | 14: @} | |
4568 | @end example | |
4569 | ||
4570 | @ssindex case-label | |
4571 | @ssindex statement-case-intro | |
4572 | @ssindex statement-case-open | |
4573 | Here, lines 4, 7, and 10 are all assigned @code{case-label} syntax, | |
4574 | while lines 5 and 8 are assigned @code{statement-case-intro}. Line 11 | |
4575 | is treated slightly differently since it contains a brace that opens a | |
4576 | block --- it is given @code{statement-case-open} syntax. | |
4577 | ||
4578 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4579 | @node Brace List Symbols, External Scope Symbols, Switch Statement Symbols, Syntactic Symbols | |
4580 | @comment node-name, next, previous, up | |
4581 | @subsection Brace List Symbols | |
4582 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4583 | ||
4584 | @cindex brace lists | |
4585 | There are a set of syntactic symbols that are used to recognize | |
4586 | constructs inside of brace lists. A brace list is defined as an | |
4587 | @code{enum} or aggregate initializer list, such as might statically | |
4588 | initialize an array of structs. The three special aggregate constructs | |
4589 | in Pike, @code{(@{ @})}, @code{([ ])} and @code{(< >)}, are treated as | |
4590 | brace lists too. An example: | |
4591 | ||
4592 | @example | |
4593 | 1: static char* ingredients[] = | |
4594 | 2: @{ | |
4595 | 3: "Ham", | |
4596 | 4: "Salt", | |
4597 | 5: NULL | |
4598 | 6: @}; | |
4599 | @end example | |
4600 | ||
4601 | @ssindex brace-list-open | |
4602 | @ssindex brace-list-intro | |
4603 | @ssindex brace-list-close | |
4604 | @ssindex brace-list-entry | |
4605 | Following convention, line 2 in this example is assigned | |
4606 | @code{brace-list-open} syntax, and line 3 is assigned | |
4607 | @code{brace-list-intro} syntax. Likewise, line 6 is assigned | |
4608 | @code{brace-list-close} syntax. Lines 4 and 5 however, are assigned | |
4609 | @code{brace-list-entry} syntax, as would all subsequent lines in this | |
4610 | initializer list. | |
4611 | ||
4612 | @ssindex brace-entry-open | |
4613 | Your static initializer might be initializing nested structures, for | |
4614 | example: | |
4615 | ||
4616 | @example | |
4617 | 1: struct intpairs[] = | |
4618 | 2: @{ | |
4619 | 3: @{ 1, 2 @}, | |
4620 | 4: @{ | |
4621 | 5: 3, | |
4622 | 6: 4 | |
4623 | 7: @} | |
4624 | 8: @{ 1, | |
4625 | 9: 2 @}, | |
4626 | 10: @{ 3, 4 @} | |
4627 | 11: @}; | |
4628 | @end example | |
4629 | ||
4630 | Here, you've already seen the analysis of lines 1, 2, 3, and 11. On | |
4631 | line 4, things get interesting; this line is assigned | |
4632 | @code{brace-entry-open} syntactic symbol because it's a bracelist entry | |
4633 | line that starts with an open brace. Lines 5 and 6 (and line 9) are | |
4634 | pretty standard, and line 7 is a @code{brace-list-close} as you'd | |
4635 | expect. Once again, line 8 is assigned as @code{brace-entry-open} as is | |
4636 | line 10. | |
4637 | ||
4638 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4639 | @node External Scope Symbols, Paren List Symbols, Brace List Symbols, Syntactic Symbols | |
4640 | @comment node-name, next, previous, up | |
4641 | @subsection External Scope Symbols | |
4642 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4643 | ||
4644 | External language definition blocks also have their own syntactic | |
4645 | symbols. In this example: | |
4646 | ||
4647 | @example | |
4648 | 1: extern "C" | |
4649 | 2: @{ | |
4650 | 3: int thing_one( int ); | |
4651 | 4: int thing_two( double ); | |
4652 | 5: @} | |
4653 | @end example | |
4654 | ||
4655 | @ssindex extern-lang-open | |
4656 | @ssindex extern-lang-close | |
4657 | @ssindex inextern-lang | |
4658 | @ssindex inclass | |
4659 | @noindent | |
4660 | line 2 is given the @code{extern-lang-open} syntax, while line 5 is given | |
4661 | the @code{extern-lang-close} syntax. The analysis for line 3 yields: | |
4662 | ||
4663 | @example | |
4664 | ((inextern-lang) (topmost-intro 14)) | |
4665 | @end example | |
4666 | ||
4667 | @noindent | |
4668 | where @code{inextern-lang} is a modifier similar in purpose to | |
4669 | @code{inclass}. | |
4670 | ||
4671 | There are various other top level blocks like @code{extern}, and they | |
4672 | are all treated in the same way except that the symbols are named after | |
4673 | the keyword that introduces the block. E.g. C++ namespace blocks get | |
4674 | the three symbols @code{namespace-open}, @code{namespace-close} and | |
4675 | @code{innamespace}. The currently recognized top level blocks are: | |
4676 | ||
4677 | @table @asis | |
4678 | @item @code{extern-lang-open}, @code{extern-lang-close}, @code{inextern-lang} | |
4679 | @code{extern} blocks in C and C++.@footnote{These should logically be | |
4680 | named @code{extern-open}, @code{extern-close} and @code{inextern}, but | |
4681 | that isn't the case for historical reasons.} | |
4682 | ||
4683 | @item @code{namespace-open}, @code{namespace-close}, @code{innamespace} | |
4684 | @ssindex namespace-open | |
4685 | @ssindex namespace-close | |
4686 | @ssindex innamespace | |
4687 | @code{namespace} blocks in C++. | |
4688 | ||
4689 | @item @code{module-open}, @code{module-close}, @code{inmodule} | |
4690 | @ssindex module-open | |
4691 | @ssindex module-close | |
4692 | @ssindex inmodule | |
4693 | @code{module} blocks in CORBA IDL. | |
4694 | ||
4695 | @item @code{composition-open}, @code{composition-close}, @code{incomposition} | |
4696 | @ssindex composition-open | |
4697 | @ssindex composition-close | |
4698 | @ssindex incomposition | |
4699 | @code{composition} blocks in CORBA CIDL. | |
4700 | @end table | |
4701 | ||
4702 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4703 | @node Paren List Symbols, Literal Symbols, External Scope Symbols, Syntactic Symbols | |
4704 | @comment node-name, next, previous, up | |
4705 | @subsection Parenthesis (Argument) List Symbols | |
4706 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4707 | ||
4708 | A number of syntactic symbols are associated with parenthesis lists, | |
4709 | a.k.a argument lists, as found in function declarations and function | |
4710 | calls. This example illustrates these: | |
4711 | ||
4712 | @example | |
4713 | 1: void a_function( int line1, | |
4714 | 2: int line2 ); | |
4715 | 3: | |
4716 | 4: void a_longer_function( | |
4717 | 5: int line1, | |
4718 | 6: int line2 | |
4719 | 7: ); | |
4720 | 8: | |
4721 | 9: void call_them( int line1, int line2 ) | |
4722 | 10: @{ | |
4723 | 11: a_function( | |
4724 | 12: line1, | |
4725 | 13: line2 | |
4726 | 14: ); | |
4727 | 15: | |
4728 | 16: a_longer_function( line1, | |
4729 | 17: line2 ); | |
4730 | 18: @} | |
4731 | @end example | |
4732 | ||
4733 | @ssindex arglist-intro | |
4734 | @ssindex arglist-close | |
4735 | Lines 5 and 12 are assigned @code{arglist-intro} syntax since they are | |
4736 | the first line following the open parenthesis, and lines 7 and 14 are | |
4737 | assigned @code{arglist-close} syntax since they contain the parenthesis | |
4738 | that closes the argument list. | |
4739 | ||
4740 | @ssindex arglist-cont-nonempty | |
4741 | @ssindex arglist-cont | |
4742 | Lines that continue argument lists can be assigned one of two syntactic | |
4743 | symbols. For example, Lines 2 and 17 | |
4744 | are assigned @code{arglist-cont-nonempty} syntax. What this means | |
4745 | is that they continue an argument list, but that the line containing the | |
4746 | parenthesis that opens the list is @emph{not empty} following the open | |
4747 | parenthesis. Contrast this against lines 6 and 13 which are assigned | |
4748 | @code{arglist-cont} syntax. This is because the parenthesis that opens | |
4749 | their argument lists is the last character on that line. | |
4750 | ||
4751 | Syntactic elements with @code{arglist-intro}, | |
4752 | @code{arglist-cont-nonempty}, and @code{arglist-close} contain two | |
4753 | buffer positions: the anchor position (the beginning of the | |
4754 | declaration or statement) and the position of the open parenthesis. | |
4755 | The latter position can be used in a line-up function (@pxref{Line-Up | |
4756 | Functions}). | |
4757 | ||
4758 | Note that there is no @code{arglist-open} syntax. This is because any | |
4759 | parenthesis that opens an argument list, appearing on a separate line, | |
4760 | is assigned the @code{statement-cont} syntax instead. | |
4761 | ||
4762 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4763 | @node Literal Symbols, Multiline Macro Symbols, Paren List Symbols, Syntactic Symbols | |
4764 | @comment node-name, next, previous, up | |
4765 | @subsection Comment String Label and Macro Symbols | |
4766 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4767 | ||
4768 | A few miscellaneous syntactic symbols that haven't been previously | |
4769 | covered are illustrated by this C++ example: | |
4770 | ||
4771 | @example | |
4772 | 1: void Bass::play( int volume ) | |
4773 | 2: const | |
4774 | 3: @{ | |
4775 | 4: /* this line starts a multiline | |
4776 | 5: * comment. This line should get `c' syntax */ | |
4777 | 6: | |
4778 | 7: char* a_multiline_string = "This line starts a multiline \ | |
4779 | 8: string. This line should get `string' syntax."; | |
4780 | 9: | |
4781 | 10: note: | |
4782 | 11: @{ | |
4783 | 12: #ifdef LOCK | |
4784 | 13: Lock acquire(); | |
4785 | 14: #endif // LOCK | |
4786 | 15: slap_pop(); | |
4787 | 16: cout << "I played " | |
4788 | 17: << "a note\n"; | |
4789 | 18: @} | |
4790 | 19: @} | |
4791 | @end example | |
4792 | ||
4793 | The lines to note in this example include: | |
4794 | ||
4795 | @itemize @bullet | |
4796 | @item | |
4797 | @ssindex func-decl-cont | |
4798 | Line 2 is assigned the @code{func-decl-cont} syntax. | |
4799 | ||
4800 | @item | |
4801 | @ssindex comment-intro | |
4802 | Line 4 is assigned both @code{defun-block-intro} @emph{and} | |
4803 | @code{comment-intro} syntax. A syntactic element with | |
4804 | @code{comment-intro} has no anchor point --- It is always accompanied | |
4805 | by another syntactic element which does have one. | |
4806 | ||
4807 | @item | |
4808 | @ssindex c | |
4809 | Line 5 is assigned @code{c} syntax. | |
4810 | ||
4811 | @item | |
4812 | @cindex syntactic whitespace | |
4813 | Line 6 which, even though it contains nothing but whitespace, is | |
4814 | assigned @code{defun-block-intro}. Note that the appearance of the | |
4815 | comment on lines 4 and 5 do not cause line 6 to be assigned | |
4816 | @code{statement} syntax because comments are considered to be | |
4817 | @dfn{syntactic whitespace}, which are ignored when analyzing | |
4818 | code. | |
4819 | ||
4820 | @item | |
4821 | @ssindex string | |
4822 | Line 8 is assigned @code{string} syntax. | |
4823 | ||
4824 | @item | |
4825 | @ssindex label | |
4826 | Line 10 is assigned @code{label} syntax. | |
4827 | ||
4828 | @item | |
4829 | @ssindex block-open | |
4830 | Line 11 is assigned @code{block-open} as well as @code{statement} | |
4831 | syntax. A @code{block-open} syntactic element doesn't have an anchor | |
4832 | position, since it always appears with another syntactic element which | |
4833 | does have one. | |
4834 | ||
4835 | @item | |
4836 | @ssindex cpp-macro | |
4837 | Lines 12 and 14 are assigned @code{cpp-macro} syntax in addition to the | |
4838 | normal syntactic symbols (@code{statement-block-intro} and | |
4839 | @code{statement}, respectively). Normally @code{cpp-macro} is | |
4840 | configured to cancel out the normal syntactic context to make all | |
4841 | preprocessor directives stick to the first column, but that's easily | |
4842 | changed if you want preprocessor directives to be indented like the rest | |
4843 | of the code. Like @code{comment-intro}, a syntactic element with | |
4844 | @code{cpp-macro} doesn't contain an anchor position. | |
4845 | ||
4846 | @item | |
4847 | @ssindex stream-op | |
4848 | Line 17 is assigned @code{stream-op} syntax. | |
4849 | @end itemize | |
4850 | ||
4851 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4852 | @node Multiline Macro Symbols, Objective-C Method Symbols, Literal Symbols, Syntactic Symbols | |
4853 | @comment node-name, next, previous, up | |
4854 | @subsection Multiline Macro Symbols | |
4855 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4856 | ||
4857 | @cindex multiline macros | |
4858 | @cindex syntactic whitespace | |
4859 | @ssindex cpp-define-intro | |
4860 | @ssindex cpp-macro-cont | |
4861 | Multiline preprocessor macro definitions are normally handled just like | |
4862 | other code, i.e. the lines inside them are indented according to the | |
4863 | syntactic analysis of the preceding lines inside the macro. The first | |
4864 | line inside a macro definition (i.e. the line after the starting line of | |
4865 | the cpp directive itself) gets @code{cpp-define-intro}. In this example: | |
4866 | ||
4867 | @example | |
4868 | 1: #define LIST_LOOP(cons, listp) \ | |
4869 | 2: for (cons = listp; !NILP (cons); cons = XCDR (cons)) \ | |
4870 | 3: if (!CONSP (cons)) \ | |
4871 | 4: signal_error ("Invalid list format", listp); \ | |
4872 | 5: else | |
4873 | @end example | |
4874 | ||
4875 | @noindent | |
4876 | line 1 is given the syntactic symbol @code{cpp-macro}. The first line | |
4877 | of a cpp directive is always given that symbol. Line 2 is given | |
4878 | @code{cpp-define-intro}, so that you can give the macro body as a whole | |
4879 | some extra indentation. Lines 3 through 5 are then analyzed as normal | |
4880 | code, i.e. @code{substatement} on lines 3 and 4, and @code{else-clause} | |
4881 | on line 5. | |
4882 | ||
4883 | The syntactic analysis inside macros can be turned off with | |
4884 | @code{c-syntactic-indentation-in-macros} (@pxref{Custom Macros}). In | |
4885 | that case, lines 2 through 5 would all be given @code{cpp-macro-cont} | |
4886 | with an anchor position pointing to the @code{#} which starts the cpp | |
4887 | directive@footnote{This is how @ccmode{} 5.28 and earlier analyzed | |
4888 | macros.}. | |
4889 | ||
4890 | @xref{Custom Macros}, for more info about the treatment of macros. | |
4891 | ||
4892 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5cee0a9c | 4893 | @node Objective-C Method Symbols, Java Symbols, Multiline Macro Symbols, Syntactic Symbols |
4009494e GM |
4894 | @comment node-name, next, previous, up |
4895 | @subsection Objective-C Method Symbols | |
4896 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4897 | ||
4898 | In Objective-C buffers, there are three additional syntactic symbols | |
4899 | assigned to various message calling constructs. Here's an example | |
4900 | illustrating these: | |
4901 | ||
4902 | @example | |
4903 | 1: - (void)setDelegate:anObject | |
4904 | 2: withStuff:stuff | |
4905 | 3: @{ | |
4906 | 4: [delegate masterWillRebind:self | |
4907 | 5: toDelegate:anObject | |
4908 | 6: withExtraStuff:stuff]; | |
4909 | 7: @} | |
4910 | @end example | |
4911 | ||
4912 | @ssindex objc-method-intro | |
4913 | @ssindex objc-method-args-cont | |
4914 | @ssindex objc-method-call-cont | |
4915 | Here, line 1 is assigned @code{objc-method-intro} syntax, and line 2 is | |
4916 | assigned @code{objc-method-args-cont} syntax. Lines 5 and 6 are both | |
4917 | assigned @code{objc-method-call-cont} syntax. | |
4918 | ||
4919 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5cee0a9c | 4920 | @node Java Symbols, Statement Block Symbols, Objective-C Method Symbols, Syntactic Symbols |
4009494e | 4921 | @comment node-name, next, previous, up |
5cee0a9c | 4922 | @subsection Java Symbols |
4009494e GM |
4923 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
4924 | ||
4925 | Java has a concept of anonymous classes which can look something like | |
4926 | this: | |
4927 | ||
4928 | @example | |
5cee0a9c AM |
4929 | 1: @@Test |
4930 | 2: public void watch(Observable o) @{ | |
4931 | 3: @@NonNull | |
4932 | 4: Observer obs = new Observer() @{ | |
4933 | 5: public void update(Observable o, Object arg) @{ | |
4934 | 6: history.addElement(arg); | |
4935 | 7: @} | |
4936 | 8: @}; | |
4937 | 9: o.addObserver(obs); | |
4938 | 10: @} | |
4009494e GM |
4939 | @end example |
4940 | ||
4941 | @ssindex inexpr-class | |
4942 | The brace following the @code{new} operator opens the anonymous class. | |
5cee0a9c | 4943 | Lines 5 and 8 are assigned the @code{inexpr-class} syntax, besides the |
4009494e GM |
4944 | @code{inclass} symbol used in normal classes. Thus, the class will be |
4945 | indented just like a normal class, with the added indentation given to | |
4946 | @code{inexpr-class}. An @code{inexpr-class} syntactic element doesn't | |
4947 | have an anchor position. | |
4948 | ||
5cee0a9c AM |
4949 | @ssindex annotation-top-cont |
4950 | @ssindex annotation-var-cont | |
4951 | Line 2 is assigned the @code{annotation-top-cont} syntax, due to it being a | |
4952 | continuation of a topmost introduction with an annotation symbol preceding | |
4953 | the current line. Similarly, line 4 is assigned the @code{annotation-var-cont} | |
4954 | syntax due to it being a continuation of a variable declaration where preceding | |
4955 | the declaration is an annotation. | |
4956 | ||
4009494e | 4957 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
5cee0a9c | 4958 | @node Statement Block Symbols, K&R Symbols, Java Symbols, Syntactic Symbols |
4009494e GM |
4959 | @comment node-name, next, previous, up |
4960 | @subsection Statement Block Symbols | |
4961 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
4962 | ||
4963 | There are a few occasions where a statement block might be used inside | |
4964 | an expression. One is in C or C++ code using the gcc extension for | |
4965 | this, e.g: | |
4966 | ||
4967 | @example | |
4968 | 1: int res = (@{ | |
4969 | 2: int y = foo (); int z; | |
4970 | 3: if (y > 0) z = y; else z = - y; | |
4971 | 4: z; | |
4972 | 5: @}); | |
4973 | @end example | |
4974 | ||
4975 | @ssindex inexpr-statement | |
4976 | Lines 2 and 5 get the @code{inexpr-statement} syntax, besides the | |
4977 | symbols they'd get in a normal block. Therefore, the indentation put on | |
4978 | @code{inexpr-statement} is added to the normal statement block | |
4979 | indentation. An @code{inexpr-statement} syntactic element doesn't | |
4980 | contain an anchor position. | |
4981 | ||
4982 | In Pike code, there are a few other situations where blocks occur inside | |
4983 | statements, as illustrated here: | |
4984 | ||
4985 | @example | |
4986 | 1: array itgob() | |
4987 | 2: @{ | |
4988 | 3: string s = map (backtrace()[-2][3..], | |
4989 | 4: lambda | |
4990 | 5: (mixed arg) | |
4991 | 6: @{ | |
4992 | 7: return sprintf ("%t", arg); | |
4993 | 8: @}) * ", " + "\n"; | |
4994 | 9: return catch @{ | |
4995 | 10: write (s + "\n"); | |
4996 | 11: @}; | |
4997 | 12: @} | |
4998 | @end example | |
4999 | ||
5000 | @ssindex inlambda | |
5001 | @ssindex lambda-intro-cont | |
5002 | Lines 4 through 8 contain a lambda function, which @ccmode{} recognizes | |
5003 | by the @code{lambda} keyword. If the function argument list is put | |
5004 | on a line of its own, as in line 5, it gets the @code{lambda-intro-cont} | |
5005 | syntax. The function body is handled as an inline method body, with the | |
5006 | addition of the @code{inlambda} syntactic symbol. This means that line | |
5007 | 6 gets @code{inlambda} and @code{inline-open}, and line 8 gets | |
5008 | @code{inline-close}@footnote{You might wonder why it doesn't get | |
5009 | @code{inlambda} too. It's because the closing brace is relative to the | |
5010 | opening brace, which stands on its own line in this example. If the | |
5011 | opening brace was hanging on the previous line, then the closing brace | |
5012 | would get the @code{inlambda} syntax too to be indented correctly.}. | |
5013 | ||
5014 | @ssindex inexpr-statement | |
5015 | On line 9, @code{catch} is a special function taking a statement block | |
5016 | as its argument. The block is handled as an in-expression statement | |
5017 | with the @code{inexpr-statement} syntax, just like the gcc extended C | |
5018 | example above. The other similar special function, @code{gauge}, is | |
5019 | handled like this too. | |
5020 | ||
5021 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5022 | @node K&R Symbols, , Statement Block Symbols, Syntactic Symbols | |
5023 | @comment node-name, next, previous, up | |
5024 | @subsection K&R Symbols | |
5025 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5026 | ||
5027 | @ssindex knr-argdecl-intro | |
5028 | @ssindex knr-argdecl | |
5029 | Two other syntactic symbols can appear in old style, non-prototyped C | |
5030 | code @footnote{a.k.a. K&R C, or Kernighan & Ritchie C}: | |
5031 | ||
5032 | @example | |
5033 | 1: int add_three_integers(a, b, c) | |
5034 | 2: int a; | |
5035 | 3: int b; | |
5036 | 4: int c; | |
5037 | 5: @{ | |
5038 | 6: return a + b + c; | |
5039 | 7: @} | |
5040 | @end example | |
5041 | ||
5042 | Here, line 2 is the first line in an argument declaration list and so is | |
5043 | given the @code{knr-argdecl-intro} syntactic symbol. Subsequent lines | |
5044 | (i.e. lines 3 and 4 in this example), are given @code{knr-argdecl} | |
5045 | syntax. | |
5046 | ||
5047 | ||
5048 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5049 | @node Indentation Calculation, , Syntactic Symbols, Indentation Engine Basics | |
5050 | @comment node-name, next, previous, up | |
5051 | @section Indentation Calculation | |
5052 | @cindex indentation | |
5053 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5054 | ||
5055 | Indentation for a line is calculated from the syntactic context | |
5056 | (@pxref{Syntactic Analysis}). | |
5057 | ||
5058 | First, a buffer position is found whose column will be the base for the | |
5059 | indentation calculation. It's the anchor position in the first | |
5060 | syntactic element that provides one that is used. If no syntactic | |
5061 | element has an anchor position then column zero is used. | |
5062 | ||
5063 | Second, the syntactic symbols in each syntactic element are looked up | |
5064 | in the @code{c-offsets-alist} style variable | |
5065 | (@pxref{c-offsets-alist}), which is an association list of syntactic | |
5066 | symbols and the offsets to apply for those symbols. These offsets are | |
5067 | added together with the base column to produce the new indentation | |
5068 | column. | |
5069 | ||
5070 | Let's use our two code examples above to see how this works. Here is | |
5071 | our first example again: | |
5072 | ||
5073 | @example | |
5074 | 1: void swap( int& a, int& b ) | |
5075 | 2: @{ | |
5076 | 3: int tmp = a; | |
5077 | 4: a = b; | |
5078 | 5: b = tmp; | |
5079 | 6: @} | |
5080 | @end example | |
5081 | ||
5082 | Let's say point is on line 3 and we hit the @key{TAB} key to reindent | |
5083 | the line. The syntactic context for that line is: | |
5084 | ||
5085 | @example | |
5086 | ((defun-block-intro 29)) | |
5087 | @end example | |
5088 | ||
5089 | @noindent | |
5090 | Since buffer position 29 is the first and only anchor position in the | |
5091 | list, @ccmode{} goes there and asks for the current column. This brace | |
5092 | is in column zero, so @ccmode{} uses @samp{0} as the base column. | |
5093 | ||
5094 | Next, @ccmode{} looks up @code{defun-block-intro} in the | |
5095 | @code{c-offsets-alist} style variable. Let's say it finds the value | |
5096 | @samp{4}; it adds this to the base column @samp{0}, yielding a running | |
5097 | total indentation of 4 spaces. | |
5098 | ||
5099 | Since there is only one syntactic element on the list for this line, | |
5100 | indentation calculation is complete, and the total indentation for the | |
5101 | line is 4 spaces. | |
5102 | ||
5103 | Here's another example: | |
5104 | ||
5105 | @example | |
5106 | 1: int add( int val, int incr, int doit ) | |
5107 | 2: @{ | |
5108 | 3: if( doit ) | |
5109 | 4: @{ | |
5110 | 5: return( val + incr ); | |
5111 | 6: @} | |
5112 | 7: return( val ); | |
5113 | 8: @} | |
5114 | @end example | |
5115 | ||
5116 | If we were to hit @kbd{TAB} on line 4 in the above example, the same | |
5117 | basic process is performed, despite the differences in the syntactic | |
5118 | context. The context for this line is: | |
5119 | ||
5120 | @example | |
5121 | ((substatement-open 46)) | |
5122 | @end example | |
5123 | ||
5124 | Here, @ccmode{} goes to buffer position 46, which is the @samp{i} in | |
5125 | @code{if} on line 3. This character is in the fourth column on that | |
5126 | line so the base column is @samp{4}. Then @ccmode{} looks up the | |
5127 | @code{substatement-open} symbol in @code{c-offsets-alist}. Let's say it | |
5128 | finds the value @samp{4}. It's added with the base column and yields an | |
5129 | indentation for the line of 8 spaces. | |
5130 | ||
5131 | Simple, huh? | |
5132 | ||
5133 | Actually, it's a bit more complicated than that since the entries on | |
5134 | @code{c-offsets-alist} can be much more than plain offsets. | |
5135 | @xref{c-offsets-alist}, for the full story. | |
5136 | ||
5137 | Anyway, the mode usually just does The Right Thing without you having to | |
5138 | think about it in this much detail. But when customizing indentation, | |
5139 | it's helpful to understand the general indentation model being used. | |
5140 | ||
5141 | As you configure @ccmode{}, you might want to set the variable | |
5142 | @code{c-echo-syntactic-information-p} to non-@code{nil} so that the | |
5143 | syntactic context and calculated offset always is echoed in the | |
5144 | minibuffer when you hit @kbd{TAB}. | |
5145 | ||
5146 | ||
5147 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5148 | @node Customizing Indentation, Custom Macros, Indentation Engine Basics, Top | |
5149 | @comment node-name, next, previous, up | |
5150 | @chapter Customizing Indentation | |
5151 | @cindex customization, indentation | |
5152 | @cindex indentation | |
5153 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5154 | ||
5155 | The principal variable for customizing indentation is the style | |
5156 | variable @code{c-offsets-alist}, which gives an @dfn{offset} (an | |
5157 | indentation rule) for each syntactic symbol. Its structure and | |
5158 | semantics are completely described in @ref{c-offsets-alist}. The | |
5159 | various ways you can set the variable, including the use of the | |
5160 | @ccmode{} style system, are described in @ref{Config Basics} and its | |
5161 | sections, in particular @ref{Style Variables}. | |
5162 | ||
5163 | The simplest and most used kind of ``offset'' setting in | |
5164 | @code{c-offsets-alist} is in terms of multiples of | |
5165 | @code{c-basic-offset}: | |
5166 | ||
5167 | @defopt c-basic-offset | |
5168 | @vindex basic-offset (c-) | |
5169 | This style variable holds the basic offset between indentation levels. | |
5170 | It's factory default is 4, but all the built-in styles set it | |
5171 | themselves, to some value between 2 (for @code{gnu} style) and 8 (for | |
5172 | @code{bsd}, @code{linux}, and @code{python} styles). | |
5173 | @end defopt | |
5174 | ||
5175 | The most flexible ``offset'' setting you can make in | |
5176 | @code{c-offsets-alist} is a line-up function (or even a list of them), | |
5177 | either one supplied by @ccmode{} (@pxref{Line-Up Functions}) or one | |
5178 | you write yourself (@pxref{Custom Line-Up}). | |
5179 | ||
5180 | Finally, in @ref{Other Indentation} you'll find the tool of last | |
5181 | resort: a hook which is called after a line has been indented. You | |
5182 | can install functions here to make ad-hoc adjustments to any line's | |
5183 | indentation. | |
5184 | ||
5185 | @menu | |
5186 | * c-offsets-alist:: | |
5187 | * Interactive Customization:: | |
5188 | * Line-Up Functions:: | |
5189 | * Custom Line-Up:: | |
5190 | * Other Indentation:: | |
5191 | @end menu | |
5192 | ||
5193 | ||
5194 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5195 | @node c-offsets-alist, Interactive Customization, Customizing Indentation, Customizing Indentation | |
5196 | @comment node-name, next, previous, up | |
5197 | @section c-offsets-alist | |
5198 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5199 | ||
5200 | This section explains the structure and semantics of the style | |
5201 | variable @code{c-offset-alist}, the principal variable for configuring | |
5202 | indentation. Details of how to set it up, and its relationship to | |
5203 | @ccmode{}'s style system are given in @ref{Style Variables}. | |
5204 | ||
5205 | @defopt c-offsets-alist | |
5206 | @vindex offsets-alist (c-) | |
5207 | This is an alist which associates an offset with each syntactic | |
5208 | symbol. This @dfn{offset} is a rule specifying how to indent a line | |
5209 | whose syntactic context matches the symbol. @xref{Syntactic | |
5210 | Analysis}. | |
5211 | ||
5212 | Note that the buffer-local binding of this alist in a @ccmode{} buffer | |
5213 | contains an entry for @emph{every} syntactic symbol. Its global | |
5214 | binding and its settings within style specifications usually contain | |
5215 | only a few entries. @xref{Style Variables}. | |
5216 | ||
5217 | The offset specification associated with any particular syntactic | |
5218 | symbol can be an integer, a variable name, a vector, a function or | |
5219 | lambda expression, a list, or one of the following special symbols: | |
5220 | @code{+}, @code{-}, @code{++}, @code{--}, @code{*}, or @code{/}. The | |
5221 | meanings of these values are described in detail below. | |
5222 | ||
5223 | Here is an example fragment of a @code{c-offsets-alist}, showing some | |
5224 | of these kinds of offsets: | |
5225 | ||
5226 | @example | |
5227 | ((statement . 0) | |
5228 | (substatement . +) | |
5229 | (cpp-macro . [0]) | |
5230 | (topmost-intro-cont . c-lineup-topmost-intro-cont) | |
5231 | (statement-block-intro . (add c-lineup-whitesmith-in-block | |
5232 | c-indent-multi-line-block)) | |
5233 | @dots{} | |
5234 | @*) | |
5235 | @end example | |
5236 | @end defopt | |
5237 | ||
5238 | @deffn Command c-set-offset (@kbd{C-c C-o}) | |
5239 | @findex set-offset (c-) | |
5240 | @kindex C-c C-o | |
5241 | This command changes the entry for a syntactic symbol in the current | |
5242 | binding of @code{c-offsets-alist}, or it inserts a new entry if there | |
5243 | isn't already one for that syntactic symbol. | |
5244 | ||
5245 | You can use @code{c-set-offsets} interactively within a @ccmode{} | |
5246 | buffer to make experimental changes to your indentation settings. | |
5247 | @kbd{C-c C-o} prompts you for the syntactic symbol to change | |
5248 | (defaulting to that of the current line) and the new offset | |
5249 | (defaulting to the current offset). | |
5250 | ||
5251 | @code{c-set-offsets} takes two arguments when used programmatically: | |
5252 | @var{symbol}, the syntactic element symbol to change and @var{offset}, | |
5253 | the new offset for that syntactic element. You can call the command | |
5254 | in your @file{.emacs} to change the global binding of | |
5255 | @code{c-offsets-alist} (@pxref{Style Variables}); you can use it in a | |
5256 | hook function to make changes from the current style. @ccmode{} | |
5257 | itself uses this function when initializing styles. | |
5258 | @end deffn | |
5259 | ||
5260 | @cindex offset specification | |
5261 | The ``offset specifications'' in @code{c-offsets-alist} can be any of | |
5262 | the following: | |
5263 | ||
5264 | @table @asis | |
5265 | @item An integer | |
5266 | The integer specifies a relative offset. All relative | |
5267 | offsets@footnote{The syntactic context @code{@w{((defun-block-intro | |
5268 | 2724) (comment-intro))}} would likely have two relative offsets.} will | |
5269 | be added together and used to calculate the indentation relative to an | |
5270 | anchor position earlier in the buffer. @xref{Indentation | |
5271 | Calculation}, for details. Most of the time, it's probably better to | |
5272 | use one of the special symbols like @code{+} than an integer (apart | |
5273 | from zero). | |
5274 | ||
5275 | @item One of the symbols @code{+}, @code{-}, @code{++}, @code{--}, @code{*}, or @code{/} | |
5276 | These special symbols describe a relative offset in multiples of | |
5277 | @code{c-basic-offset}: | |
5278 | ||
5279 | By defining a style's indentation in terms of @code{c-basic-offset}, | |
5280 | you can change the amount of whitespace given to an indentation level | |
5281 | while maintaining the same basic shape of your code. Here are the | |
5282 | values that the special symbols correspond to: | |
5283 | ||
5284 | @table @code | |
5285 | @item + | |
5286 | @code{c-basic-offset} times 1 | |
5287 | @item - | |
5288 | @code{c-basic-offset} times -1 | |
5289 | @item ++ | |
5290 | @code{c-basic-offset} times 2 | |
5291 | @item -- | |
5292 | @code{c-basic-offset} times -2 | |
5293 | @item * | |
5294 | @code{c-basic-offset} times 0.5 | |
5295 | @item / | |
5296 | @code{c-basic-offset} times -0.5 | |
5297 | @end table | |
5298 | ||
5299 | @item A vector | |
5300 | The first element of the vector, an integer, sets the absolute | |
5301 | indentation column. This will override any previously calculated | |
5302 | indentation, but won't override relative indentation calculated from | |
5303 | syntactic elements later on in the syntactic context of the line being | |
5304 | indented. @xref{Indentation Calculation}. Any elements in the vector | |
5305 | beyond the first will be ignored. | |
5306 | ||
5307 | @item A function or lambda expression | |
5308 | The function will be called and its return value will in turn be | |
5309 | evaluated as an offset specification. Functions are useful when more | |
5310 | context than just the syntactic symbol is needed to get the desired | |
5311 | indentation. @xref{Line-Up Functions}, and @ref{Custom Line-Up}, for | |
5312 | details about them. | |
5313 | ||
5314 | @item A symbol with a variable binding | |
5315 | If the symbol also has a function binding, the function takes | |
5316 | precedence over the variable. Otherwise the value of the variable is | |
5317 | used. It must be an integer (which is used as relative offset) or a | |
5318 | vector (an absolute offset). | |
5319 | ||
5320 | @item A list | |
5321 | The offset can also be a list containing several offset | |
5322 | specifications; these are evaluated recursively and combined. A list | |
5323 | is typically only useful when some of the offsets are line-up | |
5324 | functions. A common strategy is calling a sequence of functions in | |
5325 | turn until one of them recognizes that it is appropriate for the | |
5326 | source line and returns a non-@code{nil} value. | |
5327 | ||
5328 | @code{nil} values are always ignored when the offsets are combined. | |
5329 | The first element of the list specifies the method of combining the | |
5330 | non-@code{nil} offsets from the remaining elements: | |
5331 | ||
5332 | @table @code | |
5333 | @item first | |
5334 | Use the first offset that doesn't evaluate to @code{nil}. Subsequent | |
5335 | elements of the list don't get evaluated. | |
5336 | @item min | |
5337 | Use the minimum of all the offsets. All must be either relative or | |
5338 | absolute - they can't be mixed. | |
5339 | @item max | |
5340 | Use the maximum of all the offsets. All must be either relative or | |
5341 | absolute - they can't be mixed. | |
5342 | @item add | |
5343 | Add all the evaluated offsets together. Exactly one of them may be | |
5344 | absolute, in which case the result is absolute. Any relative offsets | |
5345 | that preceded the absolute one in the list will be ignored in that case. | |
5346 | @end table | |
5347 | ||
5348 | As a compatibility measure, if the first element is none of the above | |
5349 | then it too will be taken as an offset specification and the whole list | |
5350 | will be combined according to the method @code{first}. | |
5351 | @end table | |
5352 | ||
5353 | @vindex c-strict-syntax-p | |
5354 | @vindex strict-syntax-p (c-) | |
5355 | If an offset specification evaluates to @code{nil}, then a relative | |
5356 | offset of 0 (zero) is used@footnote{There is however a variable | |
5357 | @code{c-strict-syntax-p} that when set to non-@code{nil} will cause an | |
5358 | error to be signaled in that case. It's now considered obsolete since | |
5359 | it doesn't work well with some of the alignment functions that return | |
5360 | @code{nil} instead of zero. You should therefore leave | |
5361 | @code{c-strict-syntax-p} set to @code{nil}.}. | |
5362 | ||
5363 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5364 | @node Interactive Customization, Line-Up Functions, c-offsets-alist, Customizing Indentation | |
5365 | @comment node-name, next, previous, up | |
5366 | @section Interactive Customization | |
5367 | @cindex customization, interactive | |
5368 | @cindex interactive customization | |
5369 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5370 | ||
5371 | As an example of how to customize indentation, let's change the | |
5372 | style of this example@footnote{In this and subsequent examples, the | |
5373 | original code is formatted using the @samp{gnu} style unless otherwise | |
5374 | indicated. @xref{Styles}.}: | |
5375 | ||
5376 | @example | |
5377 | @group | |
5378 | 1: int add( int val, int incr, int doit ) | |
5379 | 2: @{ | |
5380 | 3: if( doit ) | |
5381 | 4: @{ | |
5382 | 5: return( val + incr ); | |
5383 | 6: @} | |
5384 | 7: return( val ); | |
5385 | 8: @} | |
5386 | @end group | |
5387 | @end example | |
5388 | ||
5389 | @noindent | |
5390 | to: | |
5391 | ||
5392 | @example | |
5393 | @group | |
5394 | 1: int add( int val, int incr, int doit ) | |
5395 | 2: @{ | |
5396 | 3: if( doit ) | |
5397 | 4: @{ | |
5398 | 5: return( val + incr ); | |
5399 | 6: @} | |
5400 | 7: return( val ); | |
5401 | 8: @} | |
5402 | @end group | |
5403 | @end example | |
5404 | ||
5405 | In other words, we want to change the indentation of braces that open a | |
5406 | block following a condition so that the braces line up under the | |
5407 | conditional, instead of being indented. Notice that the construct we | |
5408 | want to change starts on line 4. To change the indentation of a line, | |
5409 | we need to see which syntactic symbols affect the offset calculations | |
5410 | for that line. Hitting @kbd{C-c C-s} on line 4 yields: | |
5411 | ||
5412 | @example | |
5413 | ((substatement-open 44)) | |
5414 | @end example | |
5415 | ||
5416 | @noindent | |
5417 | so we know that to change the offset of the open brace, we need to | |
5418 | change the indentation for the @code{substatement-open} syntactic | |
5419 | symbol. | |
5420 | ||
5421 | To do this interactively, just hit @kbd{C-c C-o}. This prompts | |
5422 | you for the syntactic symbol to change, providing a reasonable default. | |
5423 | In this case, the default is @code{substatement-open}, which is just the | |
5424 | syntactic symbol we want to change! | |
5425 | ||
5426 | After you hit return, @ccmode{} will then prompt you for the new | |
5427 | offset value, with the old value as the default. The default in this | |
5428 | case is @samp{+}, but we want no extra indentation so enter | |
5429 | @samp{0} and @kbd{RET}. This will associate the offset 0 with the | |
5430 | syntactic symbol @code{substatement-open}. | |
5431 | ||
5432 | To check your changes quickly, just hit @kbd{C-c C-q} | |
5433 | (@code{c-indent-defun}) to reindent the entire function. The example | |
5434 | should now look like: | |
5435 | ||
5436 | @example | |
5437 | @group | |
5438 | 1: int add( int val, int incr, int doit ) | |
5439 | 2: @{ | |
5440 | 3: if( doit ) | |
5441 | 4: @{ | |
5442 | 5: return( val + incr ); | |
5443 | 6: @} | |
5444 | 7: return( val ); | |
5445 | 8: @} | |
5446 | @end group | |
5447 | @end example | |
5448 | ||
5449 | Notice how just changing the open brace offset on line 4 is all we | |
5450 | needed to do. Since the other affected lines are indented relative to | |
5451 | line 4, they are automatically indented the way you'd expect. For more | |
5452 | complicated examples, this might not always work. The general approach | |
5453 | to take is to always start adjusting offsets for lines higher up in the | |
5454 | file, then reindent and see if any following lines need further | |
5455 | adjustments. | |
5456 | ||
5457 | @c Move this bit to "Styles" (2005/10/7) | |
5458 | @deffn Command c-set-offset symbol offset | |
5459 | @findex set-offset (c-) | |
5460 | @kindex C-c C-o | |
5461 | This is the command bound to @kbd{C-c C-o}. It provides a convenient | |
5462 | way to set offsets on @code{c-offsets-alist} both interactively (see | |
5463 | the example above) and from your mode hook. | |
5464 | ||
5465 | It takes two arguments when used programmatically: @var{symbol} is the | |
5466 | syntactic element symbol to change and @var{offset} is the new offset | |
5467 | for that syntactic element. | |
5468 | @end deffn | |
5469 | @c End of MOVE THIS BIT. | |
5470 | ||
5471 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5472 | @node Line-Up Functions, Custom Line-Up, Interactive Customization, Customizing Indentation | |
5473 | @comment node-name, next, previous, up | |
5474 | @section Line-Up Functions | |
5475 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5476 | ||
5477 | @cindex line-up function | |
5478 | @cindex indentation function | |
5479 | Often there are cases when a simple offset setting on a syntactic | |
5480 | symbol isn't enough to get the desired indentation---for example, you | |
5481 | might want to line up a closing parenthesis with the matching opening | |
5482 | one rather than indenting relative to its ``anchor point''. @ccmode{} | |
5483 | provides this flexibility with @dfn{line-up functions}. | |
5484 | ||
5485 | The way you associate a line-up function with a syntactic symbol is | |
5486 | described in @ref{c-offsets-alist}. @ccmode{} comes with many | |
5487 | predefined line-up functions for common situations. If none of these | |
5488 | does what you want, you can write your own. @xref{Custom Line-Up}. | |
5489 | Sometimes, it is easier to tweak the standard indentation by adding a | |
5490 | function to @code{c-special-indent-hook} (@pxref{Other Indentation}). | |
5491 | ||
5492 | The line-up functions haven't been adapted for AWK buffers or tested | |
5493 | with them. Some of them might work serendipitously. There shouldn't be | |
5494 | any problems writing custom line-up functions for AWK mode. | |
5495 | ||
5496 | The calling convention for line-up functions is described fully in | |
5497 | @ref{Custom Line-Up}. Roughly speaking, the return value is either an | |
5498 | offset itself (such as @code{+} or @code{[0]}) or it's @code{nil}, | |
5499 | meaning ``this function is inappropriate in this case - try a | |
5500 | different one''. @xref{c-offsets-alist}. | |
5501 | ||
5502 | The subsections below describe all the standard line-up functions, | |
5503 | categorized by the sort of token the lining-up centers around. For | |
5504 | each of these functions there is a ``works with'' list that indicates | |
5505 | which syntactic symbols the function is intended to be used with. | |
5506 | ||
5507 | @macro workswith | |
5508 | @emph{Works with:@ } | |
5509 | @end macro | |
5510 | @ifinfo | |
5511 | @unmacro workswith | |
5512 | @macro workswith | |
5513 | Works with: | |
5514 | @end macro | |
5515 | @end ifinfo | |
5516 | ||
5517 | @macro sssTBasicOffset | |
5518 | <--> @i{c-basic-offset}@c | |
5519 | @end macro | |
5520 | ||
5521 | @macro sssTsssTBasicOffset | |
5522 | <--><--> @i{c-basic-offset}@c | |
5523 | @end macro | |
5524 | ||
5525 | @macro hereFn{func} | |
5526 | <- @i{\func\}@c | |
5527 | @end macro | |
5528 | ||
5529 | @c The TeX backend seems to insert extra spaces around the argument. :P | |
5530 | @iftex | |
5531 | @unmacro hereFn | |
5532 | @macro hereFn{func} | |
5533 | <-@i{\func\}@c | |
5534 | @end macro | |
5535 | @end iftex | |
5536 | ||
5537 | @menu | |
5538 | * Brace/Paren Line-Up:: | |
5539 | * List Line-Up:: | |
5540 | * Operator Line-Up:: | |
5541 | * Comment Line-Up:: | |
5542 | * Misc Line-Up:: | |
5543 | @end menu | |
5544 | ||
5545 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5546 | @node Brace/Paren Line-Up, List Line-Up, Line-Up Functions, Line-Up Functions | |
5547 | @comment node-name, next, previous, up | |
5548 | @subsection Brace and Parenthesis Line-Up Functions | |
5549 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5550 | ||
5551 | The line-up functions here calculate the indentation for braces, | |
5552 | parentheses and statements within brace blocks. | |
5553 | ||
5554 | @defun c-lineup-close-paren | |
5555 | @findex lineup-close-paren (c-) | |
5556 | Line up the closing paren under its corresponding open paren if the | |
5557 | open paren is followed by code. If the open paren ends its line, no | |
5558 | indentation is added. E.g: | |
5559 | ||
5560 | @example | |
5561 | @group | |
5562 | main (int, | |
5563 | char ** | |
5564 | ) @hereFn{c-lineup-close-paren} | |
5565 | @end group | |
5566 | @end example | |
5567 | ||
5568 | @noindent | |
5569 | and | |
5570 | ||
5571 | @example | |
5572 | @group | |
5573 | main ( | |
5574 | int, char ** | |
5575 | ) @hereFn{c-lineup-close-paren} | |
5576 | @end group | |
5577 | @end example | |
5578 | ||
5579 | As a special case, if a brace block is opened at the same line as the | |
5580 | open parenthesis of the argument list, the indentation is | |
5581 | @code{c-basic-offset} instead of the open paren column. See | |
5582 | @code{c-lineup-arglist} for further discussion of this ``DWIM'' measure. | |
5583 | ||
5584 | @workswith All @code{*-close} symbols. | |
5585 | @end defun | |
5586 | ||
5587 | @comment ------------------------------------------------------------ | |
5588 | ||
5589 | @anchor{c-lineup-arglist-close-under-paren} | |
5590 | @defun c-lineup-arglist-close-under-paren | |
5591 | @findex lineup-arglist-close-under-paren (c-) | |
5592 | Set your @code{arglist-close} syntactic symbol to this line-up function | |
5593 | so that parentheses that close argument lists will line up under the | |
5594 | parenthesis that opened the argument list. It can also be used with | |
5595 | @code{arglist-cont} and @code{arglist-cont-nonempty} to line up all | |
5596 | lines inside a parenthesis under the open paren. | |
5597 | ||
5598 | As a special case, if a brace block is opened at the same line as the | |
5599 | open parenthesis of the argument list, the indentation is | |
5600 | @code{c-basic-offset} only. See @code{c-lineup-arglist} for further | |
5601 | discussion of this ``DWIM'' measure. | |
5602 | ||
5603 | @workswith Almost all symbols, but are typically most useful on | |
5604 | @code{arglist-close}, @code{brace-list-close}, @code{arglist-cont} and | |
5605 | @code{arglist-cont-nonempty}. | |
5606 | @end defun | |
5607 | ||
5608 | @comment ------------------------------------------------------------ | |
5609 | ||
5610 | @defun c-indent-one-line-block | |
5611 | @findex indent-one-line-block (c-) | |
5612 | Indent a one line block @code{c-basic-offset} extra. E.g: | |
5613 | ||
5614 | @example | |
5615 | @group | |
5616 | if (n > 0) | |
5617 | @{m+=n; n=0;@} @hereFn{c-indent-one-line-block} | |
5618 | @sssTBasicOffset{} | |
5619 | @end group | |
5620 | @end example | |
5621 | ||
5622 | @noindent | |
5623 | and | |
5624 | ||
5625 | @example | |
5626 | @group | |
5627 | if (n > 0) | |
5628 | @{ @hereFn{c-indent-one-line-block} | |
5629 | m+=n; n=0; | |
5630 | @} | |
5631 | @end group | |
5632 | @end example | |
5633 | ||
5634 | The block may be surrounded by any kind of parenthesis characters. | |
5635 | @code{nil} is returned if the line doesn't start with a one line block, | |
5636 | which makes the function usable in list expressions. | |
5637 | ||
5638 | @workswith Almost all syntactic symbols, but most useful on the | |
5639 | @code{-open} symbols. | |
5640 | @end defun | |
5641 | ||
5642 | @comment ------------------------------------------------------------ | |
5643 | ||
5644 | @defun c-indent-multi-line-block | |
5645 | @findex indent-multi-line-block (c-) | |
5646 | Indent a multiline block @code{c-basic-offset} extra. E.g: | |
5647 | ||
5648 | @example | |
5649 | @group | |
5650 | int *foo[] = @{ | |
5651 | NULL, | |
5652 | @{17@}, @hereFn{c-indent-multi-line-block} | |
5653 | @end group | |
5654 | @end example | |
5655 | ||
5656 | @noindent | |
5657 | and | |
5658 | ||
5659 | @example | |
5660 | @group | |
5661 | int *foo[] = @{ | |
5662 | NULL, | |
5663 | @{ @hereFn{c-indent-multi-line-block} | |
5664 | 17 | |
5665 | @}, | |
5666 | @sssTBasicOffset{} | |
5667 | @end group | |
5668 | @end example | |
5669 | ||
5670 | The block may be surrounded by any kind of parenthesis characters. | |
5671 | @code{nil} is returned if the line doesn't start with a multiline | |
5672 | block, which makes the function usable in list expressions. | |
5673 | ||
5674 | @workswith Almost all syntactic symbols, but most useful on the | |
5675 | @code{-open} symbols. | |
5676 | @end defun | |
5677 | ||
5678 | @comment ------------------------------------------------------------ | |
5679 | ||
5680 | @defun c-lineup-runin-statements | |
5681 | @findex lineup-runin-statements (c-) | |
5682 | Line up statements for coding standards which place the first statement | |
5683 | in a block on the same line as the block opening brace@footnote{Run-in | |
5684 | style doesn't really work too well. You might need to write your own | |
5685 | custom line-up functions to better support this style.}. E.g: | |
5686 | ||
5687 | @example | |
5688 | @group | |
5689 | int main() | |
5690 | @{ puts ("Hello!"); | |
5691 | return 0; @hereFn{c-lineup-runin-statements} | |
5692 | @} | |
5693 | @end group | |
5694 | @end example | |
5695 | ||
5696 | If there is no statement after the opening brace to align with, | |
5697 | @code{nil} is returned. This makes the function usable in list | |
5698 | expressions. | |
5699 | ||
5700 | @workswith The @code{statement} syntactic symbol. | |
5701 | @end defun | |
5702 | ||
5703 | @comment ------------------------------------------------------------ | |
5704 | ||
5705 | @defun c-lineup-inexpr-block | |
5706 | @findex lineup-inexpr-block (c-) | |
5707 | This can be used with the in-expression block symbols to indent the | |
5708 | whole block to the column where the construct is started. E.g. for Java | |
5709 | anonymous classes, this lines up the class under the @samp{new} keyword, | |
5710 | and in Pike it lines up the lambda function body under the @samp{lambda} | |
5711 | keyword. Returns @code{nil} if the block isn't part of such a | |
5712 | construct. | |
5713 | ||
5714 | @workswith @code{inlambda}, @code{inexpr-statement}, | |
5715 | @code{inexpr-class}. | |
5716 | @end defun | |
5717 | ||
5718 | @comment ------------------------------------------------------------ | |
5719 | ||
5720 | @defun c-lineup-after-whitesmith-blocks | |
5721 | @findex lineup-after-whitesmith-blocks (c-) | |
5722 | Compensate for Whitesmith style indentation of blocks. Due to the way | |
5723 | @ccmode{} calculates anchor positions for normal lines inside blocks, | |
5724 | this function is necessary for those lines to get correct Whitesmith | |
5725 | style indentation. Consider the following examples: | |
5726 | ||
5727 | @example | |
5728 | @group | |
5729 | int foo() | |
5730 | @{ | |
5731 | a; | |
5732 | x; @hereFn{c-lineup-after-whitesmith-blocks} | |
5733 | @end group | |
5734 | @end example | |
5735 | ||
5736 | @example | |
5737 | @group | |
5738 | int foo() | |
5739 | @{ | |
5740 | @{ | |
5741 | a; | |
5742 | @} | |
5743 | x; @hereFn{c-lineup-after-whitesmith-blocks} | |
5744 | @end group | |
5745 | @end example | |
5746 | ||
5747 | The fact that the line with @code{x} is preceded by a Whitesmith style | |
5748 | indented block in the latter case and not the first should not affect | |
5749 | its indentation. But since CC Mode in cases like this uses the | |
5750 | indentation of the preceding statement as anchor position, the @code{x} | |
5751 | would in the second case be indented too much if the offset for | |
5752 | @code{statement} was set simply to zero. | |
5753 | ||
5754 | This lineup function corrects for this situation by detecting if the | |
5755 | anchor position is at an open paren character. In that case, it instead | |
5756 | indents relative to the surrounding block just like | |
5757 | @code{c-lineup-whitesmith-in-block}. | |
5758 | ||
5759 | @workswith @code{brace-list-entry}, @code{brace-entry-open}, | |
5760 | @code{statement}, @code{arglist-cont}. | |
5761 | @end defun | |
5762 | ||
5763 | @comment ------------------------------------------------------------ | |
5764 | ||
5765 | @defun c-lineup-whitesmith-in-block | |
5766 | @findex lineup-whitesmith-in-block (c-) | |
5767 | Line up lines inside a block in Whitesmith style. It's done in a way | |
5768 | that works both when the opening brace hangs and when it doesn't. E.g: | |
5769 | ||
5770 | @example | |
5771 | @group | |
5772 | something | |
5773 | @{ | |
5774 | foo; @hereFn{c-lineup-whitesmith-in-block} | |
5775 | @} | |
5776 | @end group | |
5777 | @end example | |
5778 | ||
5779 | @noindent | |
5780 | and | |
5781 | ||
5782 | @example | |
5783 | @group | |
5784 | something @{ | |
5785 | foo; @hereFn{c-lineup-whitesmith-in-block} | |
5786 | @} | |
5787 | @sssTBasicOffset{} | |
5788 | @end group | |
5789 | @end example | |
5790 | ||
5791 | In the first case the indentation is kept unchanged, in the second | |
5792 | @code{c-basic-offset} is added. | |
5793 | ||
5794 | @workswith @code{defun-close}, @code{defun-block-intro}, | |
5795 | @code{inline-close}, @code{block-close}, @code{brace-list-close}, | |
5796 | @code{brace-list-intro}, @code{statement-block-intro}, | |
5797 | @code{arglist-intro}, @code{arglist-cont-nonempty}, | |
5798 | @code{arglist-close}, and all @code{in*} symbols, e.g. @code{inclass} | |
5799 | and @code{inextern-lang}. | |
5800 | @end defun | |
5801 | ||
5802 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5803 | @node List Line-Up, Operator Line-Up, Brace/Paren Line-Up, Line-Up Functions | |
5804 | @comment node-name, next, previous, up | |
5805 | @subsection List Line-Up Functions | |
5806 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
5807 | ||
5808 | The line-up functions here calculate the indentation for lines which | |
5809 | form lists of items, usually separated by commas. | |
5810 | ||
5811 | The function @ref{c-lineup-arglist-close-under-paren}, which is mainly | |
5812 | for indenting a close parenthesis, is also useful for the lines | |
5813 | contained within parentheses. | |
5814 | ||
5815 | @defun c-lineup-arglist | |
5816 | @findex lineup-arglist (c-) | |
5817 | Line up the current argument line under the first argument. | |
5818 | ||
5819 | As a special case, if an argument on the same line as the open | |
5820 | parenthesis starts with a brace block opener, the indentation is | |
5821 | @code{c-basic-offset} only. This is intended as a ``DWIM'' measure in | |
5822 | cases like macros that contain statement blocks, e.g: | |
5823 | ||
5824 | @example | |
5825 | @group | |
5826 | A_VERY_LONG_MACRO_NAME (@{ | |
5827 | some (code, with + long, lines * in[it]); | |
5828 | @}); | |
5829 | @sssTBasicOffset{} | |
5830 | @end group | |
5831 | @end example | |
5832 | ||
5833 | This is motivated partly because it's more in line with how code | |
5834 | blocks are handled, and partly since it approximates the behavior of | |
5835 | earlier CC Mode versions, which due to inaccurate analysis tended to | |
5836 | indent such cases this way. | |
5837 | ||
5838 | @workswith @code{arglist-cont-nonempty}, @code{arglist-close}. | |
5839 | @end defun | |
5840 | ||
5841 | @comment ------------------------------------------------------------ | |
5842 | ||
5843 | @defun c-lineup-arglist-intro-after-paren | |
5844 | @findex lineup-arglist-intro-after-paren (c-) | |
5845 | Line up a line to just after the open paren of the surrounding paren or | |
5846 | brace block. | |
5847 | ||
5848 | @workswith @code{defun-block-intro}, @code{brace-list-intro}, | |
5849 | @code{statement-block-intro}, @code{statement-case-intro}, | |
5850 | @code{arglist-intro}. | |
5851 | @end defun | |
5852 | ||
5853 | @comment ------------------------------------------------------------ | |
5854 | ||
5855 | @defun c-lineup-multi-inher | |
5856 | @findex lineup-multi-inher (c-) | |
5857 | Line up the classes in C++ multiple inheritance clauses and member | |
5858 | initializers under each other. E.g: | |
5859 | ||
5860 | @example | |
5861 | @group | |
5862 | Foo::Foo (int a, int b): | |
5863 | Cyphr (a), | |
5864 | Bar (b) @hereFn{c-lineup-multi-inher} | |
5865 | @end group | |
5866 | @end example | |
5867 | ||
5868 | @noindent | |
5869 | and | |
5870 | ||
5871 | @example | |
5872 | @group | |
5873 | class Foo | |
5874 | : public Cyphr, | |
5875 | public Bar @hereFn{c-lineup-multi-inher} | |
5876 | @end group | |
5877 | @end example | |
5878 | ||
5879 | @noindent | |
5880 | and | |
5881 | ||
5882 | @example | |
5883 | @group | |
5884 | Foo::Foo (int a, int b) | |
5885 | : Cyphr (a) | |
5886 | , Bar (b) @hereFn{c-lineup-multi-inher} | |
5887 | @end group | |
5888 | @end example | |
5889 | ||
5890 | @workswith @code{inher-cont}, @code{member-init-cont}. | |
5891 | @end defun | |
5892 | ||
5893 | @comment ------------------------------------------------------------ | |
5894 | ||
5895 | @defun c-lineup-java-inher | |
5896 | @findex lineup-java-inher (c-) | |
5897 | Line up Java implements and extends declarations. If class names | |
5898 | follow on the same line as the @samp{implements}/@samp{extends} | |
5899 | keyword, they are lined up under each other. Otherwise, they are | |
5900 | indented by adding @code{c-basic-offset} to the column of the keyword. | |
5901 | E.g: | |
5902 | ||
5903 | @example | |
5904 | @group | |
5905 | class Foo | |
5906 | extends | |
5907 | Bar @hereFn{c-lineup-java-inher} | |
5908 | @sssTBasicOffset{} | |
5909 | @end group | |
5910 | @end example | |
5911 | ||
5912 | @noindent | |
5913 | and | |
5914 | ||
5915 | @example | |
5916 | @group | |
5917 | class Foo | |
5918 | extends Cyphr, | |
5919 | Bar @hereFn{c-lineup-java-inher} | |
5920 | @end group | |
5921 | @end example | |
5922 | ||
5923 | @workswith @code{inher-cont}. | |
5924 | @end defun | |
5925 | ||
5926 | @comment ------------------------------------------------------------ | |
5927 | ||
5928 | @defun c-lineup-java-throws | |
5929 | @findex lineup-java-throws (c-) | |
5930 | Line up Java throws declarations. If exception names follow on the | |
5931 | same line as the throws keyword, they are lined up under each other. | |
5932 | Otherwise, they are indented by adding @code{c-basic-offset} to the | |
5933 | column of the @samp{throws} keyword. The @samp{throws} keyword itself | |
5934 | is also indented by @code{c-basic-offset} from the function declaration | |
5935 | start if it doesn't hang. E.g: | |
5936 | ||
5937 | @example | |
5938 | @group | |
5939 | int foo() | |
5940 | throws @hereFn{c-lineup-java-throws} | |
5941 | Bar @hereFn{c-lineup-java-throws} | |
5942 | @sssTsssTBasicOffset{} | |
5943 | @end group | |
5944 | @end example | |
5945 | ||
5946 | @noindent | |
5947 | and | |
5948 | ||
5949 | @example | |
5950 | @group | |
5951 | int foo() throws Cyphr, | |
5952 | Bar, @hereFn{c-lineup-java-throws} | |
5953 | Vlod @hereFn{c-lineup-java-throws} | |
5954 | @end group | |
5955 | @end example | |
5956 | ||
5957 | @workswith @code{func-decl-cont}. | |
5958 | @end defun | |
5959 | ||
5960 | @comment ------------------------------------------------------------ | |
5961 | ||
5962 | @defun c-lineup-template-args | |
5963 | @findex lineup-template-args (c-) | |
5964 | Line up the arguments of a template argument list under each other, but | |
5965 | only in the case where the first argument is on the same line as the | |
5966 | opening @samp{<}. | |
5967 | ||
5968 | To allow this function to be used in a list expression, @code{nil} is | |
5969 | returned if there's no template argument on the first line. | |
5970 | ||
5971 | @workswith @code{template-args-cont}. | |
5972 | @end defun | |
5973 | ||
5974 | @comment ------------------------------------------------------------ | |
5975 | ||
5976 | @defun c-lineup-ObjC-method-call | |
5977 | @findex lineup-ObjC-method-call (c-) | |
5978 | For Objective-C code, line up selector args as Emacs Lisp mode does | |
5979 | with function args: go to the position right after the message receiver, | |
5980 | and if you are at the end of the line, indent the current line | |
5981 | c-basic-offset columns from the opening bracket; otherwise you are | |
5982 | looking at the first character of the first method call argument, so | |
5983 | lineup the current line with it. | |
5984 | ||
5985 | @workswith @code{objc-method-call-cont}. | |
5986 | @end defun | |
5987 | ||
5988 | @comment ------------------------------------------------------------ | |
5989 | ||
5990 | @defun c-lineup-ObjC-method-args | |
5991 | @findex lineup-ObjC-method-args (c-) | |
5992 | For Objective-C code, line up the colons that separate args. The colon | |
5993 | on the current line is aligned with the one on the first line. | |
5994 | ||
5995 | @workswith @code{objc-method-args-cont}. | |
5996 | @end defun | |
5997 | ||
5998 | @comment ------------------------------------------------------------ | |
5999 | ||
6000 | @defun c-lineup-ObjC-method-args-2 | |
6001 | @findex lineup-ObjC-method-args-2 (c-) | |
6002 | Similar to @code{c-lineup-ObjC-method-args} but lines up the colon on | |
6003 | the current line with the colon on the previous line. | |
6004 | ||
6005 | @workswith @code{objc-method-args-cont}. | |
6006 | @end defun | |
6007 | ||
6008 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6009 | @node Operator Line-Up, Comment Line-Up, List Line-Up, Line-Up Functions | |
6010 | @comment node-name, next, previous, up | |
6011 | @subsection Operator Line-Up Functions | |
6012 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6013 | ||
6014 | The line-up functions here calculate the indentation for lines which | |
6015 | start with an operator, by lining it up with something on the previous | |
6016 | line. | |
6017 | ||
6018 | @defun c-lineup-argcont | |
6019 | @findex lineup-argcont (c-) | |
6020 | Line up a continued argument. E.g: | |
6021 | ||
6022 | @example | |
6023 | @group | |
6024 | foo (xyz, aaa + bbb + ccc | |
6025 | + ddd + eee + fff); @hereFn{c-lineup-argcont} | |
6026 | @end group | |
6027 | @end example | |
6028 | ||
6029 | Only continuation lines like this are touched, @code{nil} is returned on | |
6030 | lines which are the start of an argument. | |
6031 | ||
2f0c93d1 | 6032 | Within a gcc @code{asm} block, @code{:} is recognized as an argument |
4009494e GM |
6033 | separator, but of course only between operand specifications, not in the |
6034 | expressions for the operands. | |
6035 | ||
6036 | @workswith @code{arglist-cont}, @code{arglist-cont-nonempty}. | |
6037 | @end defun | |
6038 | ||
6039 | @comment ------------------------------------------------------------ | |
6040 | ||
6041 | @defun c-lineup-arglist-operators | |
6042 | @findex lineup-arglist-operators (c-) | |
6043 | Line up lines starting with an infix operator under the open paren. | |
6044 | Return @code{nil} on lines that don't start with an operator, to leave | |
6045 | those cases to other line-up functions. Example: | |
6046 | ||
6047 | @example | |
6048 | @group | |
6049 | if ( x < 10 | |
6050 | || at_limit (x, @hereFn{c-lineup-arglist-operators} | |
6051 | list) @hereFn{c-lineup-arglist-operators@r{ returns nil}} | |
6052 | ) | |
6053 | @end group | |
6054 | @end example | |
6055 | ||
6056 | Since this function doesn't do anything for lines without an infix | |
6057 | operator you typically want to use it together with some other lineup | |
6058 | settings, e.g. as follows (the @code{arglist-close} setting is just a | |
6059 | suggestion to get a consistent style): | |
6060 | ||
6061 | @example | |
6062 | (c-set-offset 'arglist-cont | |
6063 | '(c-lineup-arglist-operators 0)) | |
6064 | (c-set-offset 'arglist-cont-nonempty | |
6065 | '(c-lineup-arglist-operators c-lineup-arglist)) | |
6066 | (c-set-offset 'arglist-close | |
6067 | '(c-lineup-arglist-close-under-paren)) | |
6068 | @end example | |
6069 | ||
6070 | @workswith @code{arglist-cont}, @code{arglist-cont-nonempty}. | |
6071 | @end defun | |
6072 | ||
6073 | @comment ------------------------------------------------------------ | |
6074 | ||
6075 | @defun c-lineup-assignments | |
6076 | @findex lineup-assignments (c-) | |
6077 | Line up the current line after the assignment operator on the first line | |
6078 | in the statement. If there isn't any, return nil to allow stacking with | |
6079 | other line-up functions. If the current line contains an assignment | |
6080 | operator too, try to align it with the first one. | |
6081 | ||
6082 | @workswith @code{topmost-intro-cont}, @code{statement-cont}, | |
6083 | @code{arglist-cont}, @code{arglist-cont-nonempty}. | |
6084 | ||
6085 | @end defun | |
6086 | ||
6087 | @comment ------------------------------------------------------------ | |
6088 | ||
6089 | @defun c-lineup-math | |
6090 | @findex lineup-math (c-) | |
6091 | Like @code{c-lineup-assignments} but indent with @code{c-basic-offset} | |
6092 | if no assignment operator was found on the first line. I.e. this | |
6093 | function is the same as specifying a list @code{(c-lineup-assignments | |
6094 | +)}. It's provided for compatibility with old configurations. | |
6095 | ||
6096 | @workswith @code{topmost-intro-cont}, @code{statement-cont}, | |
6097 | @code{arglist-cont}, @code{arglist-cont-nonempty}. | |
6098 | @end defun | |
6099 | ||
6100 | @comment ------------------------------------------------------------ | |
6101 | ||
6102 | @defun c-lineup-cascaded-calls | |
6103 | @findex lineup-cascaded-calls (c-) | |
6104 | Line up ``cascaded calls'' under each other. If the line begins with | |
6105 | @code{->} or @code{.} and the preceding line ends with one or more | |
6106 | function calls preceded by the same token, then the arrow is lined up | |
6107 | with the first of those tokens. E.g: | |
6108 | ||
6109 | @example | |
6110 | @group | |
6111 | r = proc->add(17)->add(18) | |
6112 | ->add(19) + @hereFn{c-lineup-cascaded-calls} | |
6113 | offset; @hereFn{c-lineup-cascaded-calls@r{ (inactive)}} | |
6114 | @end group | |
6115 | @end example | |
6116 | ||
6117 | In any other situation @code{nil} is returned to allow use in list | |
6118 | expressions. | |
6119 | ||
6120 | @workswith @code{topmost-intro-cont}, @code{statement-cont}, | |
6121 | @code{arglist-cont}, @code{arglist-cont-nonempty}. | |
6122 | @end defun | |
6123 | ||
6124 | @comment ------------------------------------------------------------ | |
6125 | ||
6126 | @defun c-lineup-streamop | |
6127 | @findex lineup-streamop (c-) | |
6128 | Line up C++ stream operators (i.e. @samp{<<} and @samp{>>}). | |
6129 | ||
6130 | @workswith @code{stream-op}. | |
6131 | @end defun | |
6132 | ||
6133 | @comment ------------------------------------------------------------ | |
6134 | ||
6135 | @defun c-lineup-string-cont | |
6136 | @findex lineup-string-cont (c-) | |
6137 | Line up a continued string under the one it continues. A continued | |
6138 | string in this sense is where a string literal follows directly after | |
6139 | another one. E.g: | |
6140 | ||
6141 | @example | |
6142 | @group | |
6143 | result = prefix + "A message " | |
6144 | "string."; @hereFn{c-lineup-string-cont} | |
6145 | @end group | |
6146 | @end example | |
6147 | ||
6148 | @code{nil} is returned in other situations, to allow stacking with other | |
6149 | lineup functions. | |
6150 | ||
6151 | @workswith @code{topmost-intro-cont}, @code{statement-cont}, | |
6152 | @code{arglist-cont}, @code{arglist-cont-nonempty}. | |
6153 | @end defun | |
6154 | ||
6155 | ||
6156 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6157 | @node Comment Line-Up, Misc Line-Up, Operator Line-Up, Line-Up Functions | |
6158 | @comment node-name, next, previous, up | |
6159 | @subsection Comment Line-Up Functions | |
6160 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6161 | ||
6162 | The lineup functions here calculate the indentation for several types | |
6163 | of comment structure. | |
6164 | ||
6165 | @defun c-lineup-C-comments | |
6166 | @findex lineup-C-comments (c-) | |
6167 | Line up C block comment continuation lines. Various heuristics are used | |
6168 | to handle most of the common comment styles. Some examples: | |
6169 | ||
6170 | @example | |
6171 | @group | |
6172 | /* /** /* | |
6173 | * text * text text | |
6174 | */ */ */ | |
6175 | @end group | |
6176 | @end example | |
6177 | ||
6178 | @example | |
6179 | @group | |
6180 | /* text /* /** | |
6181 | text ** text ** text | |
6182 | */ */ */ | |
6183 | @end group | |
6184 | @end example | |
6185 | ||
6186 | @example | |
6187 | @group | |
6188 | /************************************************** | |
6189 | * text | |
6190 | *************************************************/ | |
6191 | @end group | |
6192 | @end example | |
6193 | ||
6194 | @vindex comment-start-skip | |
6195 | @example | |
6196 | @group | |
6197 | /************************************************** | |
6198 | Free form text comments: | |
6199 | In comments with a long delimiter line at the | |
6200 | start, the indentation is kept unchanged for lines | |
6201 | that start with an empty comment line prefix. The | |
6202 | delimiter line is whatever matches the | |
6203 | @code{comment-start-skip} regexp. | |
6204 | **************************************************/ | |
6205 | @end group | |
6206 | @end example | |
6207 | ||
6208 | The style variable @code{c-comment-prefix-regexp} is used to recognize | |
6209 | the comment line prefix, e.g. the @samp{*} that usually starts every | |
6210 | line inside a comment. | |
6211 | ||
6212 | @workswith The @code{c} syntactic symbol. | |
6213 | @end defun | |
6214 | ||
6215 | @comment ------------------------------------------------------------ | |
6216 | ||
6217 | @defun c-lineup-comment | |
6218 | @findex lineup-comment (c-) | |
6219 | Line up a comment-only line according to the style variable | |
6220 | @code{c-comment-only-line-offset}. If the comment is lined up with a | |
6221 | comment starter on the previous line, that alignment is preserved. | |
6222 | ||
6223 | @defopt c-comment-only-line-offset | |
6224 | @vindex comment-only-line-offset (c-) | |
6225 | This style variable specifies the extra offset for the line. It can | |
6226 | contain an integer or a cons cell of the form | |
6227 | ||
6228 | @example | |
6229 | (@r{@var{non-anchored-offset}} . @r{@var{anchored-offset}}) | |
6230 | @end example | |
6231 | ||
6232 | @noindent | |
6233 | where @var{non-anchored-offset} is the amount of offset given to | |
6234 | non-column-zero anchored lines, and @var{anchored-offset} is the amount | |
6235 | of offset to give column-zero anchored lines. Just an integer as value | |
6236 | is equivalent to @code{(@r{@var{value}} . -1000)}. | |
6237 | @end defopt | |
6238 | ||
6239 | @workswith @code{comment-intro}. | |
6240 | @end defun | |
6241 | ||
6242 | @comment ------------------------------------------------------------ | |
6243 | ||
6244 | @defun c-lineup-knr-region-comment | |
6245 | @findex lineup-knr-region-comment (c-) | |
6246 | Line up a comment in the ``K&R region'' with the declaration. That is | |
6247 | the region between the function or class header and the beginning of the | |
6248 | block. E.g: | |
6249 | ||
6250 | @example | |
6251 | @group | |
6252 | int main() | |
6253 | /* Called at startup. */ @hereFn{c-lineup-knr-region-comment} | |
6254 | @{ | |
6255 | return 0; | |
6256 | @} | |
6257 | @end group | |
6258 | @end example | |
6259 | ||
6260 | Return @code{nil} if called in any other situation, to be useful in list | |
6261 | expressions. | |
6262 | ||
6263 | @workswith @code{comment-intro}. | |
6264 | @end defun | |
6265 | ||
6266 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6267 | @node Misc Line-Up, , Comment Line-Up, Line-Up Functions | |
6268 | @comment node-name, next, previous, up | |
6269 | @subsection Miscellaneous Line-Up Functions | |
6270 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6271 | ||
6272 | The line-up functions here are the odds and ends which didn't fit into | |
6273 | any earlier category. | |
6274 | ||
6275 | @defun c-lineup-dont-change | |
6276 | @findex lineup-dont-change (c-) | |
6277 | This lineup function makes the line stay at whatever indentation it | |
6278 | already has; think of it as an identity function for lineups. | |
6279 | ||
6280 | @workswith Any syntactic symbol. | |
6281 | @end defun | |
6282 | ||
6283 | @comment ------------------------------------------------------------ | |
6284 | ||
6285 | @defun c-lineup-cpp-define | |
6286 | @findex lineup-cpp-define (c-) | |
6287 | Line up macro continuation lines according to the indentation of the | |
6288 | construct preceding the macro. E.g: | |
6289 | ||
6290 | @example | |
6291 | @group | |
6292 | const char msg[] = @hereFn{@r{The beginning of the preceding construct.}} | |
6293 | \"Some text.\"; | |
6294 | ||
6295 | #define X(A, B) \ | |
6296 | do @{ \ @hereFn{c-lineup-cpp-define} | |
6297 | printf (A, B); \ | |
6298 | @} while (0) | |
6299 | @end group | |
6300 | @end example | |
6301 | ||
6302 | @noindent | |
6303 | and: | |
6304 | ||
6305 | @example | |
6306 | @group | |
6307 | int dribble() @{ | |
6308 | if (!running) @hereFn{@r{The beginning of the preceding construct.}} | |
6309 | error(\"Not running!\"); | |
6310 | ||
6311 | #define X(A, B) \ | |
6312 | do @{ \ @hereFn{c-lineup-cpp-define} | |
6313 | printf (A, B); \ | |
6314 | @} while (0) | |
6315 | @end group | |
6316 | @end example | |
6317 | ||
6318 | If @code{c-syntactic-indentation-in-macros} is non-@code{nil}, the | |
6319 | function returns the relative indentation to the macro start line to | |
6320 | allow accumulation with other offsets. E.g. in the following cases, | |
6321 | @code{cpp-define-intro} is combined with the | |
6322 | @code{statement-block-intro} that comes from the @samp{do @{} that hangs | |
6323 | on the @samp{#define} line: | |
6324 | ||
6325 | @example | |
6326 | @group | |
6327 | const char msg[] = | |
6328 | \"Some text.\"; | |
6329 | ||
6330 | #define X(A, B) do @{ \ | |
6331 | printf (A, B); \ @hereFn{c-lineup-cpp-define} | |
6332 | this->refs++; \ | |
6333 | @} while (0) @hereFn{c-lineup-cpp-define} | |
6334 | @end group | |
6335 | @end example | |
6336 | ||
6337 | @noindent | |
6338 | and: | |
6339 | ||
6340 | @example | |
6341 | @group | |
6342 | int dribble() @{ | |
6343 | if (!running) | |
6344 | error(\"Not running!\"); | |
6345 | ||
6346 | #define X(A, B) do @{ \ | |
6347 | printf (A, B); \ @hereFn{c-lineup-cpp-define} | |
6348 | this->refs++; \ | |
6349 | @} while (0) @hereFn{c-lineup-cpp-define} | |
6350 | @end group | |
6351 | @end example | |
6352 | ||
6353 | The relative indentation returned by @code{c-lineup-cpp-define} is zero | |
6354 | and two, respectively, on the two lines in each of these examples. They | |
6355 | are then added to the two column indentation that | |
6356 | @code{statement-block-intro} gives in both cases here. | |
6357 | ||
6358 | If the relative indentation is zero, then @code{nil} is returned | |
6359 | instead. That is useful in a list expression to specify the default | |
6360 | indentation on the top level. | |
6361 | ||
6362 | If @code{c-syntactic-indentation-in-macros} is @code{nil} then this | |
6363 | function keeps the current indentation, except for empty lines (ignoring | |
6364 | the ending backslash) where it takes the indentation from the closest | |
6365 | preceding nonempty line in the macro. If there's no such line in the | |
6366 | macro then the indentation is taken from the construct preceding it, as | |
6367 | described above. | |
6368 | ||
6369 | @workswith @code{cpp-define-intro}. | |
6370 | @end defun | |
6371 | ||
6372 | @comment ------------------------------------------------------------ | |
6373 | ||
6374 | @defun c-lineup-gcc-asm-reg | |
6375 | @findex lineup-gcc-asm-reg (c-) | |
6376 | Line up a gcc asm register under one on a previous line. | |
6377 | ||
6378 | @example | |
6379 | @group | |
6380 | asm ("foo %1, %0\n" | |
6381 | "bar %0, %1" | |
6382 | : "=r" (w), | |
6383 | "=r" (x) | |
6384 | : "0" (y), | |
6385 | "1" (z)); | |
6386 | @end group | |
6387 | @end example | |
6388 | ||
6389 | The @samp{x} line is aligned to the text after the @samp{:} on the | |
6390 | @samp{w} line, and similarly @samp{z} under @samp{y}. | |
6391 | ||
6392 | This is done only in an @samp{asm} or @samp{__asm__} block, and only to | |
6393 | those lines mentioned. Anywhere else @code{nil} is returned. The usual | |
6394 | arrangement is to have this routine as an extra feature at the start of | |
6395 | arglist lineups, e.g. | |
6396 | ||
6397 | @example | |
6398 | (c-lineup-gcc-asm-reg c-lineup-arglist) | |
6399 | @end example | |
6400 | ||
6401 | @workswith @code{arglist-cont}, @code{arglist-cont-nonempty}. | |
6402 | @end defun | |
6403 | ||
6404 | @comment ------------------------------------------------------------ | |
6405 | ||
6406 | @defun c-lineup-topmost-intro-cont | |
6407 | @findex lineup-topmost-intro-cont (c-) | |
6408 | Line up declaration continuation lines zero or one indentation | |
6409 | step@footnote{This function is mainly provided to mimic the behavior of | |
6410 | CC Mode 5.28 and earlier where this case wasn't handled consistently so | |
6411 | that those lines could be analyzed as either topmost-intro-cont or | |
6412 | statement-cont. It's used for @code{topmost-intro-cont} by default, but | |
6413 | you might consider using @code{+} instead.}. For lines preceding a | |
6414 | definition, zero is used. For other lines, @code{c-basic-offset} is | |
6415 | added to the indentation. E.g: | |
6416 | ||
6417 | @example | |
6418 | @group | |
6419 | int | |
6420 | neg (int i) @hereFn{c-lineup-topmost-intro-cont} | |
6421 | @{ | |
6422 | return -i; | |
6423 | @} | |
6424 | @end group | |
6425 | @end example | |
6426 | ||
6427 | @noindent | |
6428 | and | |
6429 | ||
6430 | @example | |
6431 | @group | |
6432 | struct | |
6433 | larch @hereFn{c-lineup-topmost-intro-cont} | |
6434 | @{ | |
6435 | double height; | |
6436 | @} | |
6437 | the_larch, @hereFn{c-lineup-topmost-intro-cont} | |
6438 | another_larch; @hereFn{c-lineup-topmost-intro-cont} | |
6439 | @sssTBasicOffset{} | |
6440 | @end group | |
6441 | @end example | |
6442 | ||
6443 | @noindent | |
6444 | and | |
6445 | ||
6446 | @example | |
6447 | @group | |
6448 | struct larch | |
6449 | the_larch, @hereFn{c-lineup-topmost-intro-cont} | |
6450 | another_larch; @hereFn{c-lineup-topmost-intro-cont} | |
6451 | @end group | |
6452 | @end example | |
6453 | ||
6454 | @workswith @code{topmost-intro-cont}. | |
6455 | @end defun | |
6456 | ||
6457 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6458 | @node Custom Line-Up, Other Indentation, Line-Up Functions, Customizing Indentation | |
6459 | @comment node-name, next, previous, up | |
6460 | @section Custom Line-Up Functions | |
6461 | @cindex customization, indentation functions | |
6462 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6463 | ||
6464 | The most flexible way to customize indentation is by writing custom | |
6465 | line-up functions, and associating them with specific syntactic | |
6466 | symbols (@pxref{c-offsets-alist}). Depending on the effect you want, | |
6467 | it might be better to write a @code{c-special-indent-hook} function | |
6468 | rather than a line-up function (@pxref{Other Indentation}). | |
6469 | ||
6470 | @ccmode{} comes with an extensive set of predefined line-up functions, | |
6471 | not all of which are used by the default styles. So there's a good | |
6472 | chance the function you want already exists. @xref{Line-Up | |
6473 | Functions}, for a list of them. If you write your own line-up | |
6474 | function, it's probably a good idea to start working from one of these | |
6475 | predefined functions, which can be found in the file | |
6476 | @file{cc-align.el}. If you have written a line-up function that you | |
6477 | think is generally useful, you're very welcome to contribute it; | |
6478 | please contact @email{bug-cc-mode@@gnu.org}. | |
6479 | ||
6480 | Line-up functions are passed a single argument, the syntactic | |
6481 | element (see below). The return value is a @code{c-offsets-alist} | |
6482 | offset specification: for example, an integer, a symbol such as | |
6483 | @code{+}, a vector, @code{nil}@footnote{Returning @code{nil} is useful | |
6484 | when the offset specification for a syntactic element is a list | |
6485 | containing the line-up function (@pxref{c-offsets-alist}).}, or even | |
6486 | another line-up function. Full details of these are in | |
6487 | @ref{c-offsets-alist}. | |
6488 | ||
6489 | Line-up functions must not move point or change the content of the | |
6490 | buffer (except temporarily). They are however allowed to do | |
6491 | @dfn{hidden buffer changes}, i.e. setting text properties for caching | |
6492 | purposes etc. Buffer undo recording is disabled while they run. | |
6493 | ||
6494 | The syntactic element passed as the parameter to a line-up function is | |
6495 | a cons cell of the form | |
6496 | ||
6497 | @example | |
6498 | (@r{@var{syntactic-symbol}} . @r{@var{anchor-position}}) | |
6499 | @end example | |
6500 | ||
6501 | @noindent | |
6502 | @c FIXME!!! The following sentence might be better omitted, since the | |
6503 | @c information is in the cross reference "Syntactic Analysis". 2005/10/2. | |
6504 | where @var{syntactic-symbol} is the symbol that the function was | |
6505 | called for, and @var{anchor-position} is the anchor position (if any) | |
6506 | for the construct that triggered the syntactic symbol | |
6507 | (@pxref{Syntactic Analysis}). This cons cell is how the syntactic | |
6508 | element of a line used to be represented in @ccmode{} 5.28 and | |
6509 | earlier. Line-up functions are still passed this cons cell, so as to | |
6510 | preserve compatibility with older configurations. In the future, we | |
6511 | may decide to convert to using the full list format---you can prepare | |
6512 | your setup for this by using the access functions | |
6513 | (@code{c-langelem-sym}, etc.) described below. | |
6514 | ||
6515 | @vindex c-syntactic-element | |
6516 | @vindex syntactic-element (c-) | |
6517 | @vindex c-syntactic-context | |
6518 | @vindex syntactic-context (c-) | |
6519 | Some syntactic symbols, e.g. @code{arglist-cont-nonempty}, have more | |
6520 | info in the syntactic element - typically other positions that can be | |
6521 | interesting besides the anchor position. That info can't be accessed | |
6522 | through the passed argument, which is a cons cell. Instead, you can | |
6523 | get this information from the variable @code{c-syntactic-element}, | |
6524 | which is dynamically bound to the complete syntactic element. The | |
6525 | variable @code{c-syntactic-context} might also be useful - it gets | |
6526 | dynamically bound to the complete syntactic context. @xref{Custom | |
6527 | Braces}. | |
6528 | ||
6529 | @ccmode{} provides a few functions to access parts of syntactic | |
6530 | elements in a more abstract way. Besides making the code easier to | |
6531 | read, they also hide the difference between the old cons cell form | |
6532 | used in the line-up function argument and the new list form used in | |
6533 | @code{c-syntactic-element} and everywhere else. The functions are: | |
6534 | ||
6535 | @defun c-langelem-sym langelem | |
6536 | @findex langelem-sym (c-) | |
6537 | Return the syntactic symbol in @var{langelem}. | |
6538 | @end defun | |
6539 | ||
6540 | @defun c-langelem-pos langelem | |
6541 | @findex langelem-pos (c-) | |
6542 | Return the anchor position in @var{langelem}, or nil if there is none. | |
6543 | @end defun | |
6544 | ||
6545 | @defun c-langelem-col langelem &optional preserve-point | |
6546 | @findex langelem-col (c-) | |
6547 | Return the column of the anchor position in @var{langelem}. Also move | |
6548 | the point to that position unless @var{preserve-point} is | |
6549 | non-@code{nil}. | |
6550 | @end defun | |
6551 | ||
6552 | @defun c-langelem-2nd-pos langelem | |
6553 | @findex langelem-2nd-pos (c-) | |
6554 | Return the secondary position in @var{langelem}, or @code{nil} if there | |
6555 | is none. | |
6556 | ||
6557 | Note that the return value of this function is always @code{nil} if | |
6558 | @var{langelem} is in the old cons cell form. Thus this function is | |
6559 | only meaningful when used on syntactic elements taken from | |
6560 | @code{c-syntactic-element} or @code{c-syntactic-context}. | |
6561 | @end defun | |
6562 | ||
6563 | Custom line-up functions can be as simple or as complex as you like, and | |
6564 | any syntactic symbol that appears in @code{c-offsets-alist} can have a | |
6565 | custom line-up function associated with it. | |
6566 | ||
6567 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6568 | @node Other Indentation, , Custom Line-Up, Customizing Indentation | |
6569 | @comment node-name, next, previous, up | |
6570 | @section Other Special Indentations | |
6571 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6572 | ||
536610a4 AM |
6573 | To configure macros which you invoke without a terminating @samp{;}, |
6574 | see @xref{Macros with ;}. | |
6575 | ||
4009494e GM |
6576 | Here are the remaining odds and ends regarding indentation: |
6577 | ||
6578 | @defopt c-label-minimum-indentation | |
6579 | @vindex label-minimum-indentation (c-) | |
6580 | In @samp{gnu} style (@pxref{Built-in Styles}), a minimum indentation is | |
6581 | imposed on lines inside code blocks. This minimum indentation is | |
6582 | controlled by this style variable. The default value is 1. | |
6583 | ||
6584 | @findex c-gnu-impose-minimum | |
6585 | @findex gnu-impose-minimum (c-) | |
6586 | It's the function @code{c-gnu-impose-minimum} that enforces this minimum | |
6587 | indentation. It must be present on @code{c-special-indent-hook} to | |
6588 | work. | |
6589 | @end defopt | |
6590 | ||
6591 | @defopt c-special-indent-hook | |
6592 | @vindex special-indent-hook (c-) | |
6593 | This style variable is a standard hook variable that is called after | |
6594 | every line is indented by @ccmode{}. It is called only if | |
6595 | @code{c-syntactic-indentation} is non-@code{nil} (which it is by | |
6596 | default (@pxref{Indentation Engine Basics})). You can put a function | |
6597 | on this hook to do any special indentation or ad hoc line adjustments | |
6598 | your style dictates, such as adding extra indentation to constructors | |
6599 | or destructor declarations in a class definition, etc. Sometimes it | |
6600 | is better to write a custom Line-up Function instead (@pxref{Custom | |
6601 | Line-Up}). | |
6602 | ||
6603 | When the indentation engine calls this hook, the variable | |
6604 | @code{c-syntactic-context} is bound to the current syntactic context | |
6605 | (i.e. what you would get by typing @kbd{C-c C-s} on the source line. | |
6606 | @xref{Custom Braces}.). Note that you should not change point or mark | |
6607 | inside a @code{c-special-indent-hook} function, i.e. you'll probably | |
6608 | want to wrap your function in a @code{save-excursion}@footnote{The | |
6609 | numerical value returned by @code{point} will change if you change the | |
6610 | indentation of the line within a @code{save-excursion} form, but point | |
6611 | itself will still be over the same piece of text.}. | |
6612 | ||
6613 | Setting @code{c-special-indent-hook} in style definitions is handled | |
6614 | slightly differently from other variables---A style can only add | |
6615 | functions to this hook, not remove them. @xref{Style Variables}. | |
6616 | @end defopt | |
6617 | ||
6618 | ||
6619 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6620 | @node Custom Macros, Odds and Ends, Customizing Indentation, Top | |
6621 | @comment node-name, next, previous, up | |
6622 | @chapter Customizing Macros | |
6623 | @cindex macros | |
6624 | @cindex preprocessor directives | |
6625 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6626 | ||
536610a4 AM |
6627 | Preprocessor macros in C, C++, and Objective C (introduced by |
6628 | @code{#define}) have a syntax different from the main language---for | |
6629 | example, a macro declaration is not terminated by a semicolon, and if | |
6630 | it is more than a line long, line breaks in it must be escaped with | |
6631 | backslashes. @ccmode{} has some commands to manipulate these, see | |
6632 | @ref{Macro Backslashes}. | |
6633 | ||
4009494e | 6634 | Normally, the lines in a multi-line macro are indented relative to |
a1bf7841 | 6635 | each other as though they were code. You can suppress this behavior |
4009494e GM |
6636 | by setting the following user option: |
6637 | ||
6638 | @defopt c-syntactic-indentation-in-macros | |
6639 | @vindex syntactic-indentation-in-macros (c-) | |
6640 | Enable syntactic analysis inside macros, which is the default. If this | |
6641 | is @code{nil}, all lines inside macro definitions are analyzed as | |
6642 | @code{cpp-macro-cont}. | |
6643 | @end defopt | |
6644 | ||
536610a4 AM |
6645 | Because a macro can expand into anything at all, near where one is |
6646 | invoked @ccmode{} can only indent and fontify code heuristically. | |
6647 | Sometimes it gets it wrong. Usually you should try to design your | |
6648 | macros so that they ''look like ordinary code'' when you invoke them. | |
6649 | However, one situation is so common that @ccmode{} handles it | |
6650 | specially: that is when certain macros needn't (or mustn't) be | |
6651 | followed by a @samp{;}. You need to configure @ccmode{} to handle | |
6652 | these macros properly, see @ref{Macros with ;}. | |
6653 | ||
6654 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6655 | @menu | |
91af3942 PE |
6656 | * Macro Backslashes:: |
6657 | * Macros with ;:: | |
536610a4 AM |
6658 | @end menu |
6659 | ||
6660 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6661 | @node Macro Backslashes, Macros with ;, Custom Macros, Custom Macros | |
6662 | @comment node-name, next, previous, up | |
6663 | @section Customizing Macro Backslashes | |
6664 | @cindex #define | |
6665 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6666 | ||
4009494e GM |
6667 | @ccmode{} provides some tools to help keep the line continuation |
6668 | backslashes in macros neat and tidy. Their precise action is | |
6669 | customized with these variables: | |
6670 | ||
6671 | @defopt c-backslash-column | |
6672 | @vindex backslash-column (c-) | |
6673 | @defoptx c-backslash-max-column | |
6674 | @vindex backslash-max-column (c-) | |
6675 | These variables control the alignment columns for line continuation | |
6676 | backslashes in multiline macros. They are used by the functions that | |
6677 | automatically insert or align such backslashes, | |
6678 | e.g. @code{c-backslash-region} and @code{c-context-line-break}. | |
6679 | ||
6680 | @code{c-backslash-column} specifies the minimum column for the | |
6681 | backslashes. If any line in the macro goes past this column, then the | |
6682 | next tab stop (i.e. next multiple of @code{tab-width}) in that line is | |
6683 | used as the alignment column for all the backslashes, so that they | |
6684 | remain in a single column. However, if any lines go past | |
6685 | @code{c-backslash-max-column} then the backslashes in the rest of the | |
6686 | macro will be kept at that column, so that the lines which are too | |
6687 | long ``stick out'' instead. | |
6688 | ||
6689 | Don't ever set these variables to @code{nil}. If you want to disable | |
6690 | the automatic alignment of backslashes, use | |
6691 | @code{c-auto-align-backslashes}. | |
6692 | @end defopt | |
6693 | ||
6694 | @defopt c-auto-align-backslashes | |
6695 | @vindex auto-align-backslashes (c-) | |
6696 | Align automatically inserted line continuation backslashes if | |
6697 | non-@code{nil}. When line continuation backslashes are inserted | |
6698 | automatically for line breaks in multiline macros, e.g. by | |
6699 | @code{c-context-line-break}, they are aligned with the other | |
6700 | backslashes in the same macro if this flag is set. | |
6701 | ||
6702 | If @code{c-auto-align-backslashes} is @code{nil}, automatically | |
6703 | inserted backslashes are preceded by a single space, and backslashes | |
6704 | get aligned only when you explicitly invoke the command | |
6705 | @code{c-backslash-region} (@kbd{C-c C-\}). | |
6706 | @end defopt | |
6707 | ||
536610a4 AM |
6708 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
6709 | @node Macros with ;, , Macro Backslashes, Custom Macros | |
6710 | @comment node-name, next, previous, up | |
6711 | @section Macros with semicolons | |
6712 | @cindex macros with semicolons | |
6713 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6714 | Macros which needn't (or mustn't) be followed by a semicolon when you | |
6715 | invoke them, @dfn{macros with semicolons}, are very common. These can | |
6716 | cause @ccmode{} to parse the next line wrongly as a | |
6717 | @code{statement-cont} (@pxref{Function Symbols}) and thus mis-indent | |
6718 | it. | |
6719 | ||
6720 | You can prevent this by specifying which macros have semicolons. It | |
6721 | doesn't matter whether or not such a macro has a parameter list: | |
6722 | ||
6723 | @defopt c-macro-names-with-semicolon | |
6724 | @vindex macro-names-with-semicolon (c-) | |
6725 | This buffer-local variable specifies which macros have semicolons. | |
6726 | After setting its value, you need to call | |
6727 | @code{c-make-macro-with-semi-re} for it to take effect. It should be | |
6728 | set to one of these values: | |
6729 | ||
6730 | @table @asis | |
6731 | @item nil | |
6732 | There are no macros with semicolons. | |
6733 | @item a list of strings | |
6734 | Each string is the name of a macro with a semicolon. Only valid | |
6735 | @code{#define} names are allowed here. For example, to set the | |
6736 | default value, you could write the following into your @file{.emacs}: | |
6737 | ||
6738 | @example | |
6739 | (setq c-macro-names-with-semicolon | |
6740 | '("Q_OBJECT" "Q_PROPERTY" "Q_DECLARE" "Q_ENUMS")) | |
6741 | @end example | |
6742 | ||
6743 | @item a regular expression | |
6744 | This matches each symbol which is a macro with a semicolon. It must | |
6745 | not match any string which isn't a valid @code{#define} name. For | |
6746 | example: | |
6747 | ||
6748 | @example | |
6749 | (setq c-macro-names-with-semicolon | |
6750 | "\\<\\(CLEAN_UP_AND_RETURN\\|Q_[[:upper:]]+\\)\\>") | |
6751 | @end example | |
6752 | @end table | |
6753 | @end defopt | |
6754 | ||
6755 | @defun c-make-macro-with-semi-re | |
6756 | @findex make-macro-with-semi-re (c-) | |
6757 | Call this (non-interactive) function, which sets internal variables, | |
6758 | each time you change the value of | |
6759 | @code{c-macro-names-with-semicolon}. It takes no arguments, and its | |
6760 | return value has no meaning. This function is called by @ccmode{}'s | |
6761 | initialization code. | |
6762 | @end defun | |
6763 | ||
4009494e GM |
6764 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! |
6765 | @node Odds and Ends, Sample .emacs File, Custom Macros, Top | |
6766 | @comment node-name, next, previous, up | |
6767 | @chapter Odds and Ends | |
6768 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6769 | ||
6770 | The stuff that didn't fit in anywhere else is documented here. | |
6771 | ||
6772 | @defopt c-require-final-newline | |
6773 | @vindex require-final-newline (c-) | |
6774 | Controls whether a final newline is enforced when the file is saved. | |
6775 | The value is an association list that for each language mode specifies | |
6776 | the value to give to @code{require-final-newline} (@pxref{Saving | |
6777 | Buffers,,, @lispref{}, @lispreftitle{}}) at mode initialization. If a | |
6778 | language isn't present on the association list, CC Mode won't touch | |
6779 | @code{require-final-newline} in buffers for that language. | |
6780 | ||
6781 | The default is to set @code{require-final-newline} to @code{t} in the | |
6782 | languages that mandate that source files should end with newlines. | |
6783 | These are C, C++ and Objective-C. | |
6784 | @end defopt | |
6785 | ||
6786 | @defopt c-echo-syntactic-information-p | |
6787 | @vindex echo-syntactic-information-p (c-) | |
6788 | If non-@code{nil}, the syntactic analysis for the current line is shown | |
6789 | in the echo area when it's indented (unless | |
6790 | @code{c-syntactic-indentation} is @code{nil}). That's useful when | |
6791 | finding out which syntactic symbols to modify to get the indentation you | |
6792 | want. | |
6793 | @end defopt | |
6794 | ||
6795 | @defopt c-report-syntactic-errors | |
6796 | @vindex report-syntactic-errors (c-) | |
6797 | If non-@code{nil}, certain syntactic errors are reported with a ding and | |
6798 | a message, for example when an @code{else} is indented for which there | |
6799 | is no corresponding @code{if}. | |
6800 | ||
6801 | Note however that @ccmode{} doesn't make any special effort to check for | |
6802 | syntactic errors; that's the job of the compiler. The reason it can | |
6803 | report cases like the one above is that it can't find the correct | |
6804 | anchoring position to indent the line in that case. | |
6805 | @end defopt | |
6806 | ||
6807 | ||
6808 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6809 | @node Sample .emacs File, Performance Issues, Odds and Ends, Top | |
6810 | @comment node-name, next, previous, up | |
6811 | @appendix Sample .emacs File | |
6812 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6813 | ||
6814 | Here's a sample .emacs file fragment that might help you along the way. | |
6815 | Just copy this region and paste it into your .emacs file. You might want | |
6816 | to change some of the actual values. | |
6817 | ||
6818 | @verbatim | |
6819 | ;; Make a non-standard key binding. We can put this in | |
6820 | ;; c-mode-base-map because c-mode-map, c++-mode-map, and so on, | |
6821 | ;; inherit from it. | |
6822 | (defun my-c-initialization-hook () | |
6823 | (define-key c-mode-base-map "\C-m" 'c-context-line-break)) | |
6824 | (add-hook 'c-initialization-hook 'my-c-initialization-hook) | |
6825 | ||
6826 | ;; offset customizations not in my-c-style | |
6827 | ;; This will take precedence over any setting of the syntactic symbol | |
6828 | ;; made by a style. | |
6829 | (setq c-offsets-alist '((member-init-intro . ++))) | |
6830 | ||
6831 | ;; Create my personal style. | |
6832 | (defconst my-c-style | |
6833 | '((c-tab-always-indent . t) | |
6834 | (c-comment-only-line-offset . 4) | |
6835 | (c-hanging-braces-alist . ((substatement-open after) | |
6836 | (brace-list-open))) | |
6837 | (c-hanging-colons-alist . ((member-init-intro before) | |
6838 | (inher-intro) | |
6839 | (case-label after) | |
6840 | (label after) | |
6841 | (access-label after))) | |
6842 | (c-cleanup-list . (scope-operator | |
6843 | empty-defun-braces | |
6844 | defun-close-semi)) | |
6845 | (c-offsets-alist . ((arglist-close . c-lineup-arglist) | |
6846 | (substatement-open . 0) | |
6847 | (case-label . 4) | |
6848 | (block-open . 0) | |
6849 | (knr-argdecl-intro . -))) | |
6850 | (c-echo-syntactic-information-p . t)) | |
6851 | "My C Programming Style") | |
6852 | (c-add-style "PERSONAL" my-c-style) | |
6853 | ||
6854 | ;; Customizations for all modes in CC Mode. | |
6855 | (defun my-c-mode-common-hook () | |
6856 | ;; set my personal style for the current buffer | |
6857 | (c-set-style "PERSONAL") | |
6858 | ;; other customizations | |
6859 | (setq tab-width 8 | |
6860 | ;; this will make sure spaces are used instead of tabs | |
6861 | indent-tabs-mode nil) | |
6862 | ;; we like auto-newline, but not hungry-delete | |
6863 | (c-toggle-auto-newline 1)) | |
6864 | (add-hook 'c-mode-common-hook 'my-c-mode-common-hook) | |
6865 | @end verbatim | |
6866 | ||
6867 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6868 | @node Performance Issues, Limitations and Known Bugs, Sample .emacs File, Top | |
6869 | @comment node-name, next, previous, up | |
6870 | @chapter Performance Issues | |
6871 | @cindex performance | |
6872 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6873 | ||
6874 | @comment FIXME: (ACM, 2003/5/24). Check whether AWK needs mentioning here. | |
6875 | ||
6876 | C and its derivative languages are highly complex creatures. Often, | |
6877 | ambiguous code situations arise that require @ccmode{} to scan large | |
6878 | portions of the buffer to determine syntactic context. Such | |
6879 | pathological code can cause @ccmode{} to perform fairly badly. This | |
6880 | section gives some insight in how @ccmode{} operates, how that interacts | |
6881 | with some coding styles, and what you can use to improve performance. | |
6882 | ||
6883 | The overall goal is that @ccmode{} shouldn't be overly slow (i.e. take | |
6884 | more than a fraction of a second) in any interactive operation. | |
6885 | I.e. it's tuned to limit the maximum response time in single operations, | |
6886 | which is sometimes at the expense of batch-like operations like | |
6887 | reindenting whole blocks. If you find that @ccmode{} gradually gets | |
6888 | slower and slower in certain situations, perhaps as the file grows in | |
6889 | size or as the macro or comment you're editing gets bigger, then chances | |
6890 | are that something isn't working right. You should consider reporting | |
6891 | it, unless it's something that's mentioned in this section. | |
6892 | ||
6893 | Because @ccmode{} has to scan the buffer backwards from the current | |
6894 | insertion point, and because C's syntax is fairly difficult to parse in | |
6895 | the backwards direction, @ccmode{} often tries to find the nearest | |
6896 | position higher up in the buffer from which to begin a forward scan | |
6897 | (it's typically an opening or closing parenthesis of some kind). The | |
6898 | farther this position is from the current insertion point, the slower it | |
6899 | gets. | |
6900 | ||
6901 | @findex beginning-of-defun | |
6902 | In earlier versions of @ccmode{}, we used to recommend putting the | |
6903 | opening brace of a top-level construct@footnote{E.g. a function in C, | |
6904 | or outermost class definition in C++ or Java.} into the leftmost | |
6905 | column. Earlier still, this used to be a rigid Emacs constraint, as | |
6906 | embodied in the @code{beginning-of-defun} function. @ccmode now | |
6907 | caches syntactic information much better, so that the delay caused by | |
6908 | searching for such a brace when it's not in column 0 is minimal, | |
6909 | except perhaps when you've just moved a long way inside the file. | |
6910 | ||
6911 | @findex defun-prompt-regexp | |
6912 | @vindex c-Java-defun-prompt-regexp | |
6913 | @vindex Java-defun-prompt-regexp (c-) | |
6914 | A special note about @code{defun-prompt-regexp} in Java mode: The common | |
6915 | style is to hang the opening braces of functions and classes on the | |
6916 | right side of the line, and that doesn't work well with the Emacs | |
6917 | approach. @ccmode{} comes with a constant | |
6918 | @code{c-Java-defun-prompt-regexp} which tries to define a regular | |
6919 | expression usable for this style, but there are problems with it. In | |
6920 | some cases it can cause @code{beginning-of-defun} to hang@footnote{This | |
6921 | has been observed in Emacs 19.34 and XEmacs 19.15.}. For this reason, | |
6922 | it is not used by default, but if you feel adventurous, you can set | |
6923 | @code{defun-prompt-regexp} to it in your mode hook. In any event, | |
6924 | setting and relying on @code{defun-prompt-regexp} will definitely slow | |
6925 | things down because (X)Emacs will be doing regular expression searches a | |
6926 | lot, so you'll probably be taking a hit either way! | |
6927 | ||
6928 | @ccmode{} maintains a cache of the opening parentheses of the blocks | |
6929 | surrounding the point, and it adapts that cache as the point is moved | |
6930 | around. That means that in bad cases it can take noticeable time to | |
6931 | indent a line in a new surrounding, but after that it gets fast as long | |
6932 | as the point isn't moved far off. The farther the point is moved, the | |
6933 | less useful is the cache. Since editing typically is done in ``chunks'' | |
6934 | rather than on single lines far apart from each other, the cache | |
6935 | typically gives good performance even when the code doesn't fit the | |
6936 | Emacs approach to finding the defun starts. | |
6937 | ||
6938 | @vindex c-enable-xemacs-performance-kludge-p | |
6939 | @vindex enable-xemacs-performance-kludge-p (c-) | |
6940 | XEmacs users can set the variable | |
6941 | @code{c-enable-xemacs-performance-kludge-p} to non-@code{nil}. This | |
6942 | tells @ccmode{} to use XEmacs-specific built-in functions which, in some | |
6943 | circumstances, can locate the top-most opening brace much more quickly than | |
6944 | @code{beginning-of-defun}. Preliminary testing has shown that for | |
6945 | styles where these braces are hung (e.g. most JDK-derived Java styles), | |
6946 | this hack can improve performance of the core syntax parsing routines | |
6947 | from 3 to 60 times. However, for styles which @emph{do} conform to | |
6948 | Emacs' recommended style of putting top-level braces in column zero, | |
6949 | this hack can degrade performance by about as much. Thus this variable | |
6950 | is set to @code{nil} by default, since the Emacs-friendly styles should | |
6951 | be more common (and encouraged!). Note that this variable has no effect | |
6952 | in Emacs since the necessary built-in functions don't exist (in Emacs | |
6953 | 22.1 as of this writing in February 2007). | |
6954 | ||
6955 | Text properties are used to speed up skipping over syntactic whitespace, | |
6956 | i.e. comments and preprocessor directives. Indenting a line after a | |
6957 | huge macro definition can be slow the first time, but after that the | |
6958 | text properties are in place and it should be fast (even after you've | |
6959 | edited other parts of the file and then moved back). | |
6960 | ||
6961 | Font locking can be a CPU hog, especially the font locking done on | |
6962 | decoration level 3 which tries to be very accurate. Note that that | |
6963 | level is designed to be used with a font lock support mode that only | |
6964 | fontifies the text that's actually shown, i.e. Lazy Lock or Just-in-time | |
6965 | Lock mode, so make sure you use one of them. Fontification of a whole | |
6966 | buffer with some thousand lines can often take over a minute. That is | |
6967 | a known weakness; the idea is that it never should happen. | |
6968 | ||
6969 | The most effective way to speed up font locking is to reduce the | |
6970 | decoration level to 2 by setting @code{font-lock-maximum-decoration} | |
6971 | appropriately. That level is designed to be as pretty as possible | |
6972 | without sacrificing performance. @xref{Font Locking Preliminaries}, for | |
6973 | more info. | |
6974 | ||
6975 | ||
6976 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6977 | @node Limitations and Known Bugs, FAQ, Performance Issues, Top | |
6978 | @comment node-name, next, previous, up | |
6979 | @chapter Limitations and Known Bugs | |
6980 | @cindex limitations | |
6981 | @cindex bugs | |
6982 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
6983 | ||
6984 | @itemize @bullet | |
6985 | @item | |
6986 | @ccmode{} doesn't support trigraphs. (These are character sequences | |
6987 | such as @samp{??(}, which represents @samp{[}. They date from a time | |
6988 | when some character sets didn't have all the characters that C needs, | |
6989 | and are now utterly obsolete.) | |
6990 | ||
6991 | @item | |
6992 | There is no way to apply auto newline settings (@pxref{Auto-newlines}) | |
6993 | on already typed lines. That's only a feature to ease interactive | |
6994 | editing. | |
6995 | ||
6996 | To generalize this issue a bit: @ccmode{} is not intended to be used as | |
6997 | a reformatter for old code in some more or less batch-like way. With | |
6998 | the exception of some functions like @code{c-indent-region}, it's only | |
6999 | geared to be used interactively to edit new code. There's currently no | |
7000 | intention to change this goal. | |
7001 | ||
7002 | If you want to reformat old code, you're probably better off using some | |
7003 | other tool instead, e.g. @ref{Top, , GNU indent, indent, The `indent' | |
7004 | Manual}, which has more powerful reformatting capabilities than | |
7005 | @ccmode{}. | |
7006 | ||
7007 | @item | |
7008 | The support for C++ templates (in angle brackets) is not yet complete. | |
7009 | When a non-nested template is used in a declaration, @ccmode{} indents | |
7010 | it and font-locks it OK. Templates used in expressions, and nested | |
7011 | templates do not fare so well. Sometimes a workaround is to refontify | |
7012 | the expression after typing the closing @samp{>}. | |
7013 | ||
f1bb4ee1 AM |
7014 | @item |
7015 | In a @dfn{k&r region} (the part of an old-fashioned C function | |
7016 | declaration which specifies the types of its parameters, coming | |
7017 | between the parameter list and the opening brace), there should be at | |
7018 | most 20 top-level parenthesis and bracket pairs. This limit has been | |
7019 | imposed for performance reasons. If it is violated, the source file | |
7020 | might be incorrectly indented or fontified. | |
7021 | ||
4009494e GM |
7022 | @item |
7023 | On loading @ccmode{}, sometimes this error message appears: | |
7024 | ||
7025 | @example | |
7026 | File mode specification error: (void-variable c-font-lock-keywords-3) | |
7027 | @end example | |
7028 | ||
7029 | This is due to a bug in the function @code{eval-after-load} in some | |
7030 | versions of (X)Emacs. It can manifest itself when there is a symbolic | |
7031 | link in the path of the directory which contains (X)Emacs. As a | |
7032 | workaround, put the following into your @file{.emacs} file, fairly | |
7033 | early on: | |
7034 | ||
7035 | @example | |
7036 | (defun my-load-cc-fonts () | |
7037 | (require "cc-fonts")) | |
7038 | (add-hook 'c-initialization-hook 'my-load-cc-fonts) | |
7039 | @end example | |
7040 | @end itemize | |
7041 | ||
7042 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7043 | @node FAQ, Updating CC Mode, Limitations and Known Bugs, Top | |
7044 | @comment node-name, next, previous, up | |
7045 | @appendix Frequently Asked Questions | |
7046 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7047 | ||
7048 | @itemize @bullet | |
7049 | @item | |
7050 | @emph{How can I change the indent level from 4 spaces to 2 spaces?} | |
7051 | ||
7052 | Set the variable @code{c-basic-offset}. @xref{Getting Started}. | |
7053 | ||
7054 | @item | |
7055 | @kindex RET | |
7056 | @kindex C-j | |
7057 | @emph{Why doesn't the @kbd{RET} key indent the new line?} | |
7058 | ||
7059 | Emacs' convention is that @kbd{RET} just adds a newline, and that | |
7060 | @kbd{C-j} adds a newline and indents it. You can make @kbd{RET} do this | |
7061 | too by adding this to your @code{c-initialization-hook}: | |
7062 | ||
7063 | @example | |
7064 | (define-key c-mode-base-map "\C-m" 'c-context-line-break) | |
7065 | @end example | |
7066 | ||
7067 | @xref{Getting Started}. This is a very common question. If you want | |
7068 | this to be the default behavior, don't lobby us, lobby RMS! @t{:-)} | |
7069 | ||
7070 | @item | |
7071 | @emph{How do I stop my code jumping all over the place when I type?} | |
7072 | ||
7073 | Deactivate ``electric minor mode'' with @kbd{C-c C-l}. @xref{Getting | |
7074 | Started}. | |
7075 | ||
7076 | @item | |
7077 | @kindex C-x h | |
7078 | @kindex C-M-\ | |
7079 | @emph{How do I reindent the whole file?} | |
7080 | ||
7081 | Visit the file and hit @kbd{C-x h} to mark the whole buffer. Then hit | |
7082 | @kbd{C-M-\}. @xref{Indentation Commands}. | |
7083 | ||
7084 | @item | |
7085 | @kindex C-M-q | |
7086 | @kindex C-M-u | |
7087 | @emph{How do I reindent the current block?} | |
7088 | ||
7089 | First move to the brace which opens the block with @kbd{C-M-u}, then | |
7090 | reindent that expression with @kbd{C-M-q}. @xref{Indentation | |
7091 | Commands}. | |
7092 | ||
7093 | @item | |
7094 | @emph{I put @code{(c-set-offset 'substatement-open 0)} in my | |
7095 | @file{.emacs} file but I get an error saying that @code{c-set-offset}'s | |
7096 | function definition is void. What's wrong?} | |
7097 | ||
7098 | This means that @ccmode{} hasn't yet been loaded into your Emacs | |
7099 | session by the time the @code{c-set-offset} call is reached, most | |
7100 | likely because @ccmode{} is being autoloaded. Instead of putting the | |
7101 | @code{c-set-offset} line in your top-level @file{.emacs} file, put it | |
7102 | in your @code{c-initialization-hook} (@pxref{CC Hooks}), or simply | |
7103 | modify @code{c-offsets-alist} directly: | |
7104 | ||
7105 | @example | |
7106 | (setq c-offsets-alist '((substatement-open . 0))) | |
7107 | @end example | |
7108 | ||
7109 | @item | |
7110 | @cindex open paren in column zero | |
7111 | @emph{I have an open paren character at column zero inside a comment or | |
7112 | multiline string literal, and it causes the fontification and/or | |
7113 | indentation to go haywire. What gives?} | |
7114 | ||
7115 | It's due to the ad-hoc rule in (X)Emacs that such open parens always | |
7116 | start defuns (which translates to functions, classes, namespaces or any | |
7117 | other top-level block constructs in the @ccmode{} languages). | |
7118 | @ifset XEMACS | |
7119 | @xref{Defuns,,, xemacs, XEmacs User's Manual}, for details. | |
7120 | @end ifset | |
7121 | @ifclear XEMACS | |
7122 | @xref{Left Margin Paren,,, emacs, GNU Emacs Manual}, for details | |
7123 | (@xref{Defuns,,, emacs, GNU Emacs Manual}, in the Emacs 20 manual). | |
7124 | @end ifclear | |
7125 | ||
7126 | This heuristic is built into the core syntax analysis routines in | |
7127 | (X)Emacs, so it's not really a @ccmode{} issue. However, in Emacs | |
7128 | 21.1 it became possible to turn it off@footnote{Using the variable | |
7129 | @code{open-paren-in-column-0-is-defun-start}.} and @ccmode{} does so | |
7130 | there since it's got its own system to keep track of blocks. | |
7131 | ||
7132 | @end itemize | |
7133 | ||
7134 | ||
7135 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7136 | @node Updating CC Mode, Mailing Lists and Bug Reports, FAQ, Top | |
7137 | @comment node-name, next, previous, up | |
7138 | @appendix Getting the Latest CC Mode Release | |
7139 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7140 | ||
7141 | @ccmode{} has been standard with all versions of Emacs since 19.34 and | |
7142 | of XEmacs since 19.16. | |
7143 | ||
7144 | @cindex web site | |
7145 | Due to release schedule skew, it is likely that all of these Emacsen | |
7146 | have old versions of @ccmode{} and so should be upgraded. Access to the | |
7147 | @ccmode{} source code, as well as more detailed information on Emacsen | |
7148 | compatibility, etc. are all available on the web site: | |
7149 | ||
7150 | @quotation | |
7151 | @uref{http://cc-mode.sourceforge.net/} | |
7152 | @end quotation | |
7153 | ||
7154 | ||
7155 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7156 | @node Mailing Lists and Bug Reports, GNU Free Documentation License, Updating CC Mode, Top | |
7157 | @comment node-name, next, previous, up | |
7158 | @appendix Mailing Lists and Submitting Bug Reports | |
7159 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7160 | ||
7161 | @kindex C-c C-b | |
7162 | @findex c-submit-bug-report | |
7163 | @findex submit-bug-report (c-) | |
7164 | To report bugs, use the @kbd{C-c C-b} (bound to | |
7165 | @code{c-submit-bug-report}) command. This provides vital information | |
7166 | we need to reproduce your problem. Make sure you include a concise, | |
7167 | but complete code example. Please try to boil your example down to | |
7168 | just the essential code needed to reproduce the problem, and include | |
7169 | an exact recipe of steps needed to expose the bug. Be especially sure | |
7170 | to include any code that appears @emph{before} your bug example, if | |
7171 | you think it might affect our ability to reproduce it. | |
7172 | ||
7173 | Please try to produce the problem in an Emacs instance without any | |
7174 | customizations loaded (i.e. start it with the @samp{-q --no-site-file} | |
7175 | arguments). If it works correctly there, the problem might be caused | |
7176 | by faulty customizations in either your own or your site | |
7177 | configuration. In that case, we'd appreciate it if you isolate the | |
7178 | Emacs Lisp code that triggers the bug and include it in your report. | |
7179 | ||
7180 | @cindex bug report mailing list | |
7181 | Bug reports should be sent to @email{bug-cc-mode@@gnu.org}. You can | |
7182 | also send other questions and suggestions (kudos? @t{;-)} to that | |
7183 | address. It's a mailing list which you can join or browse an archive | |
7184 | of; see the web site at @uref{http://cc-mode.sourceforge.net/} for | |
7185 | further details. | |
7186 | ||
7187 | @cindex announcement mailing list | |
7188 | If you want to get announcements of new @ccmode{} releases, send the | |
7189 | word @emph{subscribe} in the body of a message to | |
7190 | @email{cc-mode-announce-request@@lists.sourceforge.net}. It's possible | |
7191 | to subscribe from the web site too. Announcements will also be posted | |
7192 | to the Usenet newsgroups @code{gnu.emacs.sources}, @code{comp.emacs}, | |
7193 | @code{comp.emacs.xemacs}, @code{comp.lang.c}, @code{comp.lang.c++}, | |
7194 | @code{comp.lang.objective-c}, @code{comp.lang.java.softwaretools}, | |
7195 | @code{comp.lang.idl}, and @code{comp.lang.awk}. | |
7196 | @c There is no newsgroup for Pike. :-( | |
7197 | ||
7198 | ||
7199 | @node GNU Free Documentation License, Command and Function Index, Mailing Lists and Bug Reports, Top | |
7200 | @appendix GNU Free Documentation License | |
7201 | @include doclicense.texi | |
7202 | ||
7203 | ||
7204 | @c Removed the tentative node "Mode Initialization" from here, 2005/8/27. | |
7205 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7206 | @node Command and Function Index, Variable Index, GNU Free Documentation License, Top | |
7207 | @comment node-name, next, previous, up | |
7208 | @unnumbered Command and Function Index | |
7209 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7210 | ||
7211 | Since most @ccmode{} commands are prepended with the string | |
7212 | @samp{c-}, each appears under its @code{c-@var{thing}} name and its | |
7213 | @code{@var{thing} (c-)} name. | |
7214 | @iftex | |
7215 | @sp 2 | |
7216 | @end iftex | |
7217 | @printindex fn | |
7218 | ||
7219 | ||
7220 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7221 | @node Variable Index, Concept and Key Index, Command and Function Index, Top | |
7222 | @comment node-name, next, previous, up | |
7223 | @unnumbered Variable Index | |
7224 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7225 | ||
7226 | Since most @ccmode{} variables are prepended with the string | |
7227 | @samp{c-}, each appears under its @code{c-@var{thing}} name and its | |
7228 | @code{@var{thing} (c-)} name. | |
7229 | @iftex | |
7230 | @sp 2 | |
7231 | @end iftex | |
7232 | @printindex vr | |
7233 | ||
7234 | ||
7235 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7236 | @node Concept and Key Index, , Variable Index, Top | |
7237 | @comment node-name, next, previous, up | |
7238 | @unnumbered Concept and Key Index | |
7239 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7240 | ||
7241 | @printindex cp | |
7242 | ||
7243 | ||
7244 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7245 | @comment Epilogue. | |
7246 | @comment !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! | |
7247 | ||
4009494e | 7248 | @bye |