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6f585e44 | 1 | @c This is part of the Emacs manual. |
4e6835db | 2 | @c Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc. |
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3 | @c See file emacs.texi for copying conditions. |
4 | @c | |
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5 | @c This file is included either in emacs-xtra.texi (when producing the |
6 | @c printed version) or in the main Emacs manual (for the on-line version). | |
7 | @node Fortran | |
8 | @section Fortran Mode | |
9 | @cindex Fortran mode | |
10 | @cindex mode, Fortran | |
11 | ||
12 | Fortran mode provides special motion commands for Fortran statements | |
13 | and subprograms, and indentation commands that understand Fortran | |
14 | conventions of nesting, line numbers and continuation statements. | |
15 | Fortran mode has support for Auto Fill mode that breaks long lines into | |
16 | proper Fortran continuation lines. | |
17 | ||
18 | Special commands for comments are provided because Fortran comments | |
19 | are unlike those of other languages. Built-in abbrevs optionally save | |
20 | typing when you insert Fortran keywords. | |
21 | ||
22 | Use @kbd{M-x fortran-mode} to switch to this major mode. This | |
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23 | command runs the hook @code{fortran-mode-hook}. |
24 | @iftex | |
25 | @xref{Hooks,,, emacs, the Emacs Manual}. | |
26 | @end iftex | |
27 | @ifnottex | |
28 | @xref{Hooks}. | |
29 | @end ifnottex | |
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30 | |
31 | @cindex Fortran77 and Fortran90 | |
32 | @findex f90-mode | |
33 | @findex fortran-mode | |
34 | Fortran mode is meant for editing Fortran77 ``fixed format'' (and also | |
35 | ``tab format'') source code. For editing the modern Fortran90 or | |
36 | Fortran95 ``free format'' source code, use F90 mode (@code{f90-mode}). | |
37 | Emacs normally uses Fortran mode for files with extension @samp{.f}, | |
38 | @samp{.F} or @samp{.for}, and F90 mode for the extension @samp{.f90} and | |
39 | @samp{.f95}. GNU Fortran supports both kinds of format. | |
40 | ||
41 | @menu | |
42 | * Motion: Fortran Motion. Moving point by statements or subprograms. | |
43 | * Indent: Fortran Indent. Indentation commands for Fortran. | |
44 | * Comments: Fortran Comments. Inserting and aligning comments. | |
45 | * Autofill: Fortran Autofill. Auto fill support for Fortran. | |
46 | * Columns: Fortran Columns. Measuring columns for valid Fortran. | |
47 | * Abbrev: Fortran Abbrev. Built-in abbrevs for Fortran keywords. | |
48 | @end menu | |
49 | ||
50 | @node Fortran Motion | |
51 | @subsection Motion Commands | |
52 | ||
53 | In addition to the normal commands for moving by and operating on | |
54 | ``defuns'' (Fortran subprograms---functions and subroutines, as well as | |
55 | modules for F90 mode), Fortran mode provides special commands to move by | |
56 | statements and other program units. | |
57 | ||
58 | @table @kbd | |
59 | @kindex C-c C-n @r{(Fortran mode)} | |
60 | @findex fortran-next-statement | |
61 | @findex f90-next-statement | |
62 | @item C-c C-n | |
63 | Move to the beginning of the next statement | |
64 | (@code{fortran-next-statement}/@code{f90-next-statement}). | |
65 | ||
66 | @kindex C-c C-p @r{(Fortran mode)} | |
67 | @findex fortran-previous-statement | |
68 | @findex f90-previous-statement | |
69 | @item C-c C-p | |
70 | Move to the beginning of the previous statement | |
71 | (@code{fortran-previous-statement}/@code{f90-previous-statement}). | |
72 | If there is no previous statement (i.e. if called from the first | |
73 | statement in the buffer), move to the start of the buffer. | |
74 | ||
75 | @kindex C-c C-e @r{(F90 mode)} | |
76 | @findex f90-next-block | |
77 | @item C-c C-e | |
78 | Move point forward to the start of the next code block | |
79 | (@code{f90-next-block}). A code block is a subroutine, | |
80 | @code{if}--@code{endif} statement, and so forth. This command exists | |
81 | for F90 mode only, not Fortran mode. With a numeric argument, this | |
82 | moves forward that many blocks. | |
83 | ||
84 | @kindex C-c C-a @r{(F90 mode)} | |
85 | @findex f90-previous-block | |
86 | @item C-c C-a | |
87 | Move point backward to the previous code block | |
88 | (@code{f90-previous-block}). This is like @code{f90-next-block}, but | |
89 | moves backwards. | |
90 | ||
91 | @kindex C-M-n @r{(Fortran mode)} | |
92 | @findex fortran-end-of-block | |
93 | @findex f90-end-of-block | |
94 | @item C-M-n | |
95 | Move to the end of the current code block | |
96 | (@code{fortran-end-of-block}/@code{f90-end-of-block}). With a numeric | |
8a75579f | 97 | argument, move forward that number of blocks. The mark is set before |
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98 | moving point. The F90 mode version of this command checks for |
99 | consistency of block types and labels (if present), but it does not | |
100 | check the outermost block since that may be incomplete. | |
101 | ||
102 | @kindex C-M-p @r{(Fortran mode)} | |
103 | @findex fortran-beginning-of-block | |
104 | @findex f90-beginning-of-block | |
105 | @item C-M-p | |
106 | Move to the start of the current code block | |
107 | (@code{fortran-beginning-of-block}/@code{f90-beginning-of-block}). This | |
108 | is like @code{fortran-end-of-block}, but moves backwards. | |
109 | @end table | |
110 | ||
111 | @node Fortran Indent | |
112 | @subsection Fortran Indentation | |
113 | ||
114 | Special commands and features are needed for indenting Fortran code in | |
115 | order to make sure various syntactic entities (line numbers, comment line | |
116 | indicators and continuation line flags) appear in the columns that are | |
117 | required for standard, fixed (or tab) format Fortran. | |
118 | ||
119 | @menu | |
120 | * Commands: ForIndent Commands. Commands for indenting and filling Fortran. | |
121 | * Contline: ForIndent Cont. How continuation lines indent. | |
122 | * Numbers: ForIndent Num. How line numbers auto-indent. | |
123 | * Conv: ForIndent Conv. Conventions you must obey to avoid trouble. | |
124 | * Vars: ForIndent Vars. Variables controlling Fortran indent style. | |
125 | @end menu | |
126 | ||
127 | @node ForIndent Commands | |
128 | @subsubsection Fortran Indentation and Filling Commands | |
129 | ||
130 | @table @kbd | |
131 | @item C-M-j | |
132 | Break the current line at point and set up a continuation line | |
133 | (@code{fortran-split-line}). | |
134 | @item M-^ | |
135 | Join this line to the previous line (@code{fortran-join-line}). | |
136 | @item C-M-q | |
137 | Indent all the lines of the subprogram point is in | |
138 | (@code{fortran-indent-subprogram}). | |
139 | @item M-q | |
140 | Fill a comment block or statement. | |
141 | @end table | |
142 | ||
143 | @kindex C-M-q @r{(Fortran mode)} | |
144 | @findex fortran-indent-subprogram | |
145 | The key @kbd{C-M-q} runs @code{fortran-indent-subprogram}, a command | |
146 | to reindent all the lines of the Fortran subprogram (function or | |
147 | subroutine) containing point. | |
148 | ||
149 | @kindex C-M-j @r{(Fortran mode)} | |
150 | @findex fortran-split-line | |
151 | The key @kbd{C-M-j} runs @code{fortran-split-line}, which splits | |
152 | a line in the appropriate fashion for Fortran. In a non-comment line, | |
153 | the second half becomes a continuation line and is indented | |
154 | accordingly. In a comment line, both halves become separate comment | |
155 | lines. | |
156 | ||
157 | @kindex M-^ @r{(Fortran mode)} | |
158 | @kindex C-c C-d @r{(Fortran mode)} | |
159 | @findex fortran-join-line | |
160 | @kbd{M-^} or @kbd{C-c C-d} runs the command @code{fortran-join-line}, | |
161 | which joins a continuation line back to the previous line, roughly as | |
162 | the inverse of @code{fortran-split-line}. The point must be on a | |
163 | continuation line when this command is invoked. | |
164 | ||
165 | @kindex M-q @r{(Fortran mode)} | |
166 | @kbd{M-q} in Fortran mode fills the comment block or statement that | |
167 | point is in. This removes any excess statement continuations. | |
168 | ||
169 | @node ForIndent Cont | |
170 | @subsubsection Continuation Lines | |
171 | @cindex Fortran continuation lines | |
172 | ||
173 | @vindex fortran-continuation-string | |
174 | Most Fortran77 compilers allow two ways of writing continuation lines. | |
175 | If the first non-space character on a line is in column 5, then that | |
176 | line is a continuation of the previous line. We call this @dfn{fixed | |
177 | format}. (In GNU Emacs we always count columns from 0; but note that | |
178 | the Fortran standard counts from 1.) The variable | |
179 | @code{fortran-continuation-string} specifies what character to put in | |
180 | column 5. A line that starts with a tab character followed by any digit | |
181 | except @samp{0} is also a continuation line. We call this style of | |
5a7f4c1b | 182 | continuation @dfn{tab format}. (Fortran90 introduced ``free format,'' |
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183 | with another style of continuation lines). |
184 | ||
185 | @vindex indent-tabs-mode @r{(Fortran mode)} | |
186 | @vindex fortran-analyze-depth | |
187 | @vindex fortran-tab-mode-default | |
188 | Fortran mode can use either style of continuation line. When you | |
189 | enter Fortran mode, it tries to deduce the proper continuation style | |
190 | automatically from the buffer contents. It does this by scanning up to | |
191 | @code{fortran-analyze-depth} (default 100) lines from the start of the | |
192 | buffer. The first line that begins with either a tab character or six | |
193 | spaces determines the choice. If the scan fails (for example, if the | |
194 | buffer is new and therefore empty), the value of | |
195 | @code{fortran-tab-mode-default} (@code{nil} for fixed format, and | |
196 | non-@code{nil} for tab format) is used. @samp{/t} in the mode line | |
197 | indicates tab format is selected. Fortran mode sets the value of | |
198 | @code{indent-tabs-mode} accordingly. | |
199 | ||
200 | If the text on a line starts with the Fortran continuation marker | |
201 | @samp{$}, or if it begins with any non-whitespace character in column | |
202 | 5, Fortran mode treats it as a continuation line. When you indent a | |
203 | continuation line with @key{TAB}, it converts the line to the current | |
204 | continuation style. When you split a Fortran statement with | |
205 | @kbd{C-M-j}, the continuation marker on the newline is created according | |
206 | to the continuation style. | |
207 | ||
208 | The setting of continuation style affects several other aspects of | |
209 | editing in Fortran mode. In fixed format mode, the minimum column | |
210 | number for the body of a statement is 6. Lines inside of Fortran | |
211 | blocks that are indented to larger column numbers always use only the | |
212 | space character for whitespace. In tab format mode, the minimum | |
213 | column number for the statement body is 8, and the whitespace before | |
214 | column 8 must always consist of one tab character. | |
215 | ||
216 | @node ForIndent Num | |
217 | @subsubsection Line Numbers | |
218 | ||
219 | If a number is the first non-whitespace in the line, Fortran | |
220 | indentation assumes it is a line number and moves it to columns 0 | |
221 | through 4. (Columns always count from 0 in GNU Emacs.) | |
222 | ||
223 | @vindex fortran-line-number-indent | |
224 | Line numbers of four digits or less are normally indented one space. | |
225 | The variable @code{fortran-line-number-indent} controls this; it | |
226 | specifies the maximum indentation a line number can have. The default | |
227 | value of the variable is 1. Fortran mode tries to prevent line number | |
228 | digits passing column 4, reducing the indentation below the specified | |
229 | maximum if necessary. If @code{fortran-line-number-indent} has the | |
230 | value 5, line numbers are right-justified to end in column 4. | |
231 | ||
232 | @vindex fortran-electric-line-number | |
233 | Simply inserting a line number is enough to indent it according to | |
234 | these rules. As each digit is inserted, the indentation is recomputed. | |
235 | To turn off this feature, set the variable | |
236 | @code{fortran-electric-line-number} to @code{nil}. | |
237 | ||
238 | ||
239 | @node ForIndent Conv | |
240 | @subsubsection Syntactic Conventions | |
241 | ||
242 | Fortran mode assumes that you follow certain conventions that simplify | |
243 | the task of understanding a Fortran program well enough to indent it | |
244 | properly: | |
245 | ||
246 | @itemize @bullet | |
247 | @item | |
248 | Two nested @samp{do} loops never share a @samp{continue} statement. | |
249 | ||
250 | @item | |
251 | Fortran keywords such as @samp{if}, @samp{else}, @samp{then}, @samp{do} | |
252 | and others are written without embedded whitespace or line breaks. | |
253 | ||
254 | Fortran compilers generally ignore whitespace outside of string | |
255 | constants, but Fortran mode does not recognize these keywords if they | |
256 | are not contiguous. Constructs such as @samp{else if} or @samp{end do} | |
257 | are acceptable, but the second word should be on the same line as the | |
258 | first and not on a continuation line. | |
259 | @end itemize | |
260 | ||
261 | @noindent | |
262 | If you fail to follow these conventions, the indentation commands may | |
263 | indent some lines unaesthetically. However, a correct Fortran program | |
264 | retains its meaning when reindented even if the conventions are not | |
265 | followed. | |
266 | ||
267 | @node ForIndent Vars | |
268 | @subsubsection Variables for Fortran Indentation | |
269 | ||
270 | @vindex fortran-do-indent | |
271 | @vindex fortran-if-indent | |
272 | @vindex fortran-structure-indent | |
273 | @vindex fortran-continuation-indent | |
274 | @vindex fortran-check-all-num@dots{} | |
275 | @vindex fortran-minimum-statement-indent@dots{} | |
276 | Several additional variables control how Fortran indentation works: | |
277 | ||
278 | @table @code | |
279 | @item fortran-do-indent | |
280 | Extra indentation within each level of @samp{do} statement (default 3). | |
281 | ||
282 | @item fortran-if-indent | |
283 | Extra indentation within each level of @samp{if}, @samp{select case}, or | |
284 | @samp{where} statements (default 3). | |
285 | ||
286 | @item fortran-structure-indent | |
287 | Extra indentation within each level of @samp{structure}, @samp{union}, | |
288 | @samp{map}, or @samp{interface} statements (default 3). | |
289 | ||
290 | @item fortran-continuation-indent | |
291 | Extra indentation for bodies of continuation lines (default 5). | |
292 | ||
293 | @item fortran-check-all-num-for-matching-do | |
294 | In Fortran77, a numbered @samp{do} statement is ended by any statement | |
295 | with a matching line number. It is common (but not compulsory) to use a | |
296 | @samp{continue} statement for this purpose. If this variable has a | |
297 | non-@code{nil} value, indenting any numbered statement must check for a | |
298 | @samp{do} that ends there. If you always end @samp{do} statements with | |
299 | a @samp{continue} line (or if you use the more modern @samp{enddo}), | |
300 | then you can speed up indentation by setting this variable to | |
301 | @code{nil}. The default is @code{nil}. | |
302 | ||
303 | @item fortran-blink-matching-if | |
304 | If this is @code{t}, indenting an @samp{endif} (or @samp{enddo} | |
305 | statement moves the cursor momentarily to the matching @samp{if} (or | |
306 | @samp{do}) statement to show where it is. The default is @code{nil}. | |
307 | ||
308 | @item fortran-minimum-statement-indent-fixed | |
309 | Minimum indentation for Fortran statements when using fixed format | |
310 | continuation line style. Statement bodies are never indented less than | |
311 | this much. The default is 6. | |
312 | ||
313 | @item fortran-minimum-statement-indent-tab | |
314 | Minimum indentation for Fortran statements for tab format continuation line | |
315 | style. Statement bodies are never indented less than this much. The | |
316 | default is 8. | |
317 | @end table | |
318 | ||
319 | The variables controlling the indentation of comments are described in | |
320 | the following section. | |
321 | ||
322 | @node Fortran Comments | |
323 | @subsection Fortran Comments | |
324 | ||
325 | The usual Emacs comment commands assume that a comment can follow a | |
326 | line of code. In Fortran77, the standard comment syntax requires an | |
327 | entire line to be just a comment. Therefore, Fortran mode replaces the | |
328 | standard Emacs comment commands and defines some new variables. | |
329 | ||
330 | @vindex fortran-comment-line-start | |
331 | Fortran mode can also handle the Fortran90 comment syntax where comments | |
332 | start with @samp{!} and can follow other text. Because only some Fortran77 | |
333 | compilers accept this syntax, Fortran mode will not insert such comments | |
334 | unless you have said in advance to do so. To do this, set the variable | |
335 | @code{fortran-comment-line-start} to @samp{"!"}. | |
336 | ||
337 | @table @kbd | |
338 | @item M-; | |
339 | Align comment or insert new comment (@code{fortran-indent-comment}). | |
340 | ||
341 | @item C-x ; | |
342 | Applies to nonstandard @samp{!} comments only. | |
343 | ||
344 | @item C-c ; | |
345 | Turn all lines of the region into comments, or (with argument) turn them back | |
346 | into real code (@code{fortran-comment-region}). | |
347 | @end table | |
348 | ||
349 | @findex fortran-indent-comment | |
350 | @kbd{M-;} in Fortran mode is redefined as the command | |
351 | @code{fortran-indent-comment}. Like the usual @kbd{M-;} command, this | |
352 | recognizes any kind of existing comment and aligns its text appropriately; | |
353 | if there is no existing comment, a comment is inserted and aligned. But | |
354 | inserting and aligning comments are not the same in Fortran mode as in | |
355 | other modes. | |
356 | ||
357 | When a new comment must be inserted, if the current line is blank, a | |
358 | full-line comment is inserted. On a non-blank line, a nonstandard @samp{!} | |
359 | comment is inserted if you have said you want to use them. Otherwise a | |
360 | full-line comment is inserted on a new line before the current line. | |
361 | ||
362 | Nonstandard @samp{!} comments are aligned like comments in other | |
363 | languages, but full-line comments are different. In a standard full-line | |
364 | comment, the comment delimiter itself must always appear in column zero. | |
365 | What can be aligned is the text within the comment. You can choose from | |
366 | three styles of alignment by setting the variable | |
367 | @code{fortran-comment-indent-style} to one of these values: | |
368 | ||
369 | @vindex fortran-comment-indent-style | |
370 | @vindex fortran-comment-line-extra-indent | |
371 | @table @code | |
372 | @item fixed | |
373 | Align the text at a fixed column, which is the sum of | |
374 | @code{fortran-comment-line-extra-indent} and the minimum statement | |
375 | indentation. This is the default. | |
376 | ||
377 | The minimum statement indentation is | |
378 | @code{fortran-minimum-statement-indent-fixed} for fixed format | |
379 | continuation line style and @code{fortran-minimum-statement-indent-tab} | |
380 | for tab format style. | |
381 | ||
382 | @item relative | |
383 | Align the text as if it were a line of code, but with an additional | |
384 | @code{fortran-comment-line-extra-indent} columns of indentation. | |
385 | ||
386 | @item nil | |
387 | Don't move text in full-line comments automatically. | |
388 | @end table | |
389 | ||
390 | @vindex fortran-comment-indent-char | |
391 | In addition, you can specify the character to be used to indent within | |
392 | full-line comments by setting the variable | |
393 | @code{fortran-comment-indent-char} to the single-character string you want | |
394 | to use. | |
395 | ||
396 | @vindex fortran-directive-re | |
397 | Compiler directive lines, or preprocessor lines, have much the same | |
398 | appearance as comment lines. It is important, though, that such lines | |
399 | never be indented at all, no matter what the value of | |
400 | @code{fortran-comment-indent-style}. The variable | |
401 | @code{fortran-directive-re} is a regular expression that specifies which | |
402 | lines are directives. Matching lines are never indented, and receive | |
403 | distinctive font-locking. | |
404 | ||
405 | The normal Emacs comment command @kbd{C-x ;} has not been redefined. If | |
406 | you use @samp{!} comments, this command can be used with them. Otherwise | |
407 | it is useless in Fortran mode. | |
408 | ||
409 | @kindex C-c ; @r{(Fortran mode)} | |
410 | @findex fortran-comment-region | |
411 | @vindex fortran-comment-region | |
412 | The command @kbd{C-c ;} (@code{fortran-comment-region}) turns all the | |
413 | lines of the region into comments by inserting the string @samp{C$$$} at | |
414 | the front of each one. With a numeric argument, it turns the region | |
415 | back into live code by deleting @samp{C$$$} from the front of each line | |
416 | in it. The string used for these comments can be controlled by setting | |
417 | the variable @code{fortran-comment-region}. Note that here we have an | |
418 | example of a command and a variable with the same name; these two uses | |
419 | of the name never conflict because in Lisp and in Emacs it is always | |
420 | clear from the context which one is meant. | |
421 | ||
422 | @node Fortran Autofill | |
423 | @subsection Auto Fill in Fortran Mode | |
424 | ||
425 | Fortran mode has specialized support for Auto Fill mode, which is a | |
426 | minor mode that automatically splits statements as you insert them | |
427 | when they become too wide. Splitting a statement involves making | |
428 | continuation lines using @code{fortran-continuation-string} | |
429 | (@pxref{ForIndent Cont}). This splitting happens when you type | |
430 | @key{SPC}, @key{RET}, or @key{TAB}, and also in the Fortran | |
431 | indentation commands. You activate Auto Fill in Fortran mode in the | |
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432 | normal way. |
433 | @iftex | |
434 | @xref{Auto Fill,,, emacs, the Emacs Manual}. | |
435 | @end iftex | |
436 | @ifnottex | |
437 | @xref{Auto Fill}. | |
438 | @end ifnottex | |
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439 | |
440 | @vindex fortran-break-before-delimiters | |
441 | Auto Fill breaks lines at spaces or delimiters when the lines get | |
442 | longer than the desired width (the value of @code{fill-column}). The | |
443 | delimiters (besides whitespace) that Auto Fill can break at are | |
444 | @samp{+}, @samp{-}, @samp{/}, @samp{*}, @samp{=}, @samp{<}, @samp{>}, | |
445 | and @samp{,}. The line break comes after the delimiter if the | |
446 | variable @code{fortran-break-before-delimiters} is @code{nil}. | |
447 | Otherwise (and by default), the break comes before the delimiter. | |
448 | ||
449 | To enable Auto Fill in all Fortran buffers, add | |
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450 | @code{turn-on-auto-fill} to @code{fortran-mode-hook}. |
451 | @iftex | |
452 | @xref{Hooks,,, emacs, the Emacs Manual}. | |
453 | @end iftex | |
454 | @ifnottex | |
455 | @xref{Hooks}. | |
456 | @end ifnottex | |
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457 | |
458 | @node Fortran Columns | |
459 | @subsection Checking Columns in Fortran | |
460 | ||
461 | @table @kbd | |
462 | @item C-c C-r | |
463 | Display a ``column ruler'' momentarily above the current line | |
464 | (@code{fortran-column-ruler}). | |
465 | @item C-c C-w | |
466 | Split the current window horizontally temporarily so that it is 72 | |
467 | columns wide (@code{fortran-window-create-momentarily}). This may | |
468 | help you avoid making lines longer than the 72-character limit that | |
469 | some Fortran compilers impose. | |
470 | @item C-u C-c C-w | |
471 | Split the current window horizontally so that it is 72 columns wide | |
472 | (@code{fortran-window-create}). You can then continue editing. | |
473 | @item M-x fortran-strip-sequence-nos | |
474 | Delete all text in column 72 and beyond. | |
475 | @end table | |
476 | ||
477 | @kindex C-c C-r @r{(Fortran mode)} | |
478 | @findex fortran-column-ruler | |
479 | The command @kbd{C-c C-r} (@code{fortran-column-ruler}) shows a column | |
480 | ruler momentarily above the current line. The comment ruler is two lines | |
481 | of text that show you the locations of columns with special significance in | |
482 | Fortran programs. Square brackets show the limits of the columns for line | |
483 | numbers, and curly brackets show the limits of the columns for the | |
484 | statement body. Column numbers appear above them. | |
485 | ||
486 | Note that the column numbers count from zero, as always in GNU Emacs. | |
487 | As a result, the numbers may be one less than those you are familiar | |
488 | with; but the positions they indicate in the line are standard for | |
489 | Fortran. | |
490 | ||
491 | @vindex fortran-column-ruler-fixed | |
492 | @vindex fortran-column-ruler-tabs | |
493 | The text used to display the column ruler depends on the value of the | |
494 | variable @code{indent-tabs-mode}. If @code{indent-tabs-mode} is | |
495 | @code{nil}, then the value of the variable | |
496 | @code{fortran-column-ruler-fixed} is used as the column ruler. | |
497 | Otherwise, the value of the variable @code{fortran-column-ruler-tab} is | |
498 | displayed. By changing these variables, you can change the column ruler | |
499 | display. | |
500 | ||
501 | @kindex C-c C-w @r{(Fortran mode)} | |
502 | @findex fortran-window-create-momentarily | |
503 | @kbd{C-c C-w} (@code{fortran-window-create-momentarily}) temporarily | |
504 | splits the current window horizontally, making a window 72 columns | |
505 | wide, so you can see any lines that are too long. Type a space to | |
506 | restore the normal width. | |
507 | ||
508 | @kindex C-u C-c C-w @r{(Fortran mode)} | |
509 | @findex fortran-window-create | |
510 | You can also split the window horizontally and continue editing with | |
511 | the split in place. To do this, use @kbd{C-u C-c C-w} (@code{M-x | |
512 | fortran-window-create}). By editing in this window you can | |
513 | immediately see when you make a line too wide to be correct Fortran. | |
514 | ||
515 | @findex fortran-strip-sequence-nos | |
516 | The command @kbd{M-x fortran-strip-sequence-nos} deletes all text in | |
517 | column 72 and beyond, on all lines in the current buffer. This is the | |
518 | easiest way to get rid of old sequence numbers. | |
519 | ||
520 | @node Fortran Abbrev | |
521 | @subsection Fortran Keyword Abbrevs | |
522 | ||
523 | Fortran mode provides many built-in abbrevs for common keywords and | |
524 | declarations. These are the same sort of abbrev that you can define | |
525 | yourself. To use them, you must turn on Abbrev mode. | |
1bbe7139 | 526 | @iftex |
c5184807 | 527 | @xref{Abbrevs,,, emacs, the Emacs Manual}. |
1bbe7139 EZ |
528 | @end iftex |
529 | @ifnottex | |
530 | @xref{Abbrevs}. | |
531 | @end ifnottex | |
c5184807 EZ |
532 | |
533 | The built-in abbrevs are unusual in one way: they all start with a | |
534 | semicolon. You cannot normally use semicolon in an abbrev, but Fortran | |
535 | mode makes this possible by changing the syntax of semicolon to ``word | |
536 | constituent.'' | |
537 | ||
538 | For example, one built-in Fortran abbrev is @samp{;c} for | |
539 | @samp{continue}. If you insert @samp{;c} and then insert a punctuation | |
540 | character such as a space or a newline, the @samp{;c} expands automatically | |
541 | to @samp{continue}, provided Abbrev mode is enabled.@refill | |
542 | ||
543 | Type @samp{;?} or @samp{;C-h} to display a list of all the built-in | |
544 | Fortran abbrevs and what they stand for. | |
14831d20 MB |
545 | |
546 | @ignore | |
547 | arch-tag: 23ed7c36-1517-4646-9235-2d5ade5f06f6 | |
548 | @end ignore |