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04a19a79 | 1 | ;;; -*- lexical-binding: t -*- |
813f532d | 2 | ;;; ielm.el --- interaction mode for Emacs Lisp |
b578f267 | 3 | |
ba318903 | 4 | ;; Copyright (C) 1994, 2001-2014 Free Software Foundation, Inc. |
813f532d RS |
5 | |
6 | ;; Author: David Smith <maa036@lancaster.ac.uk> | |
34dc21db | 7 | ;; Maintainer: emacs-devel@gnu.org |
813f532d RS |
8 | ;; Created: 25 Feb 1994 |
9 | ;; Keywords: lisp | |
10 | ||
11 | ;; This file is part of GNU Emacs. | |
12 | ||
eb3fa2cf | 13 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
813f532d | 14 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
15 | ;; the Free Software Foundation, either version 3 of the License, or |
16 | ;; (at your option) any later version. | |
813f532d RS |
17 | |
18 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
eb3fa2cf | 24 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
813f532d RS |
25 | |
26 | ;;; Commentary: | |
27 | ||
e848854a | 28 | ;; Provides a nice interface to evaluating Emacs Lisp expressions. |
813f532d RS |
29 | ;; Input is handled by the comint package, and output is passed |
30 | ;; through the pretty-printer. | |
31 | ||
813f532d RS |
32 | ;; To start: M-x ielm. Type C-h m in the *ielm* buffer for more info. |
33 | ||
813f532d RS |
34 | ;;; Code: |
35 | ||
36 | (require 'comint) | |
37 | (require 'pp) | |
38 | ||
39 | ;;; User variables | |
40 | ||
94114394 RS |
41 | (defgroup ielm nil |
42 | "Interaction mode for Emacs Lisp." | |
43 | :group 'lisp) | |
44 | ||
45 | ||
46 | (defcustom ielm-noisy t | |
61c11870 | 47 | "If non-nil, IELM will beep on error." |
94114394 RS |
48 | :type 'boolean |
49 | :group 'ielm) | |
813f532d | 50 | |
759f960a LT |
51 | (defcustom ielm-prompt-read-only t |
52 | "If non-nil, the IELM prompt is read only. | |
7655d378 | 53 | The read only region includes the newline before the prompt. |
759f960a | 54 | Setting this variable does not affect existing IELM runs. |
016b8f71 | 55 | This works by setting the buffer-local value of `comint-prompt-read-only'. |
7655d378 LT |
56 | Setting that value directly affects new prompts in the current buffer. |
57 | ||
58 | If this option is enabled, then the safe way to temporarily | |
61c11870 | 59 | override the read-only-ness of IELM prompts is to call |
7655d378 LT |
60 | `comint-kill-whole-line' or `comint-kill-region' with no |
61 | narrowing in effect. This way you will be certain that none of | |
62 | the remaining prompts will be accidentally messed up. You may | |
865fe16f | 63 | wish to put something like the following in your init file: |
7655d378 LT |
64 | |
65 | \(add-hook 'ielm-mode-hook | |
04a19a79 DC |
66 | (lambda () |
67 | (define-key ielm-map \"\\C-w\" 'comint-kill-region) | |
68 | (define-key ielm-map [C-S-backspace] | |
69 | 'comint-kill-whole-line))) | |
7655d378 LT |
70 | |
71 | If you set `comint-prompt-read-only' to t, you might wish to use | |
72 | `comint-mode-hook' and `comint-mode-map' instead of | |
73 | `ielm-mode-hook' and `ielm-map'. That will affect all comint | |
61c11870 | 74 | buffers, including IELM buffers. If you sometimes use IELM on |
7655d378 LT |
75 | text-only terminals or with `emacs -nw', you might wish to use |
76 | another binding for `comint-kill-whole-line'." | |
759f960a LT |
77 | :type 'boolean |
78 | :group 'ielm | |
bf247b6e | 79 | :version "22.1") |
759f960a | 80 | |
40cf8f25 | 81 | (defcustom ielm-prompt "ELISP> " |
759f960a | 82 | "Prompt used in IELM. |
016b8f71 | 83 | Setting this variable does not affect existing IELM runs. |
ee9cd72d LT |
84 | |
85 | Interrupting the IELM process with \\<ielm-map>\\[comint-interrupt-subjob], | |
86 | and then restarting it using \\[ielm], makes the then current | |
016b8f71 | 87 | default value affect _new_ prompts. Unless the new prompt |
ee9cd72d LT |
88 | differs only in text properties from the old one, IELM will no |
89 | longer recognize the old prompts. However, executing \\[ielm] | |
90 | does not update the prompt of an *ielm* buffer with a running process. | |
9eca7c03 | 91 | For IELM buffers that are not called `*ielm*', you can execute |
ee9cd72d LT |
92 | \\[inferior-emacs-lisp-mode] in that IELM buffer to update the value, |
93 | for new prompts. This works even if the buffer has a running process." | |
40cf8f25 | 94 | :type 'string |
759f960a | 95 | :group 'ielm) |
813f532d | 96 | |
016b8f71 LT |
97 | (defvar ielm-prompt-internal "ELISP> " |
98 | "Stored value of `ielm-prompt' in the current IELM buffer. | |
99 | This is an internal variable used by IELM. Its purpose is to | |
100 | prevent a running IELM process from being messed up when the user | |
101 | customizes `ielm-prompt'.") | |
102 | ||
94114394 | 103 | (defcustom ielm-dynamic-return t |
61c11870 | 104 | "Controls whether \\<ielm-map>\\[ielm-return] has intelligent behavior in IELM. |
e848854a | 105 | If non-nil, \\[ielm-return] evaluates input for complete sexps, or inserts a newline |
94114394 RS |
106 | and indents for incomplete sexps. If nil, always inserts newlines." |
107 | :type 'boolean | |
108 | :group 'ielm) | |
e848854a | 109 | |
94114394 | 110 | (defcustom ielm-dynamic-multiline-inputs t |
61c11870 | 111 | "Force multiline inputs to start from column zero? |
e848854a RS |
112 | If non-nil, after entering the first line of an incomplete sexp, a newline |
113 | will be inserted after the prompt, moving the input to the next line. | |
114 | This gives more frame width for large indented sexps, and allows functions | |
94114394 RS |
115 | such as `edebug-defun' to work with such inputs." |
116 | :type 'boolean | |
117 | :group 'ielm) | |
813f532d | 118 | |
94114394 | 119 | (defcustom ielm-mode-hook nil |
61c11870 | 120 | "Hooks to be run when IELM (`inferior-emacs-lisp-mode') is started." |
ad78f432 | 121 | :options '(eldoc-mode) |
94114394 RS |
122 | :type 'hook |
123 | :group 'ielm) | |
61c11870 | 124 | (defvaralias 'inferior-emacs-lisp-mode-hook 'ielm-mode-hook) |
813f532d | 125 | |
d38e7d5f RS |
126 | (defvar * nil |
127 | "Most recent value evaluated in IELM.") | |
128 | ||
129 | (defvar ** nil | |
130 | "Second-most-recent value evaluated in IELM.") | |
131 | ||
132 | (defvar *** nil | |
133 | "Third-most-recent value evaluated in IELM.") | |
690ec649 | 134 | |
565f89ec SM |
135 | (defvar ielm-match-data nil |
136 | "Match data saved at the end of last command.") | |
137 | ||
1322516b | 138 | (defvar *1 nil |
5d9655bb RS |
139 | "During IELM evaluation, most recent value evaluated in IELM. |
140 | Normally identical to `*'. However, if the working buffer is an IELM | |
141 | buffer, distinct from the process buffer, then `*' gives the value in | |
71296446 | 142 | the working buffer, `*1' the value in the process buffer. |
5d9655bb RS |
143 | The intended value is only accessible during IELM evaluation.") |
144 | ||
145 | (defvar *2 nil | |
146 | "During IELM evaluation, second-most-recent value evaluated in IELM. | |
147 | Normally identical to `**'. However, if the working buffer is an IELM | |
148 | buffer, distinct from the process buffer, then `**' gives the value in | |
149 | the working buffer, `*2' the value in the process buffer. | |
150 | The intended value is only accessible during IELM evaluation.") | |
151 | ||
152 | (defvar *3 nil | |
153 | "During IELM evaluation, third-most-recent value evaluated in IELM. | |
154 | Normally identical to `***'. However, if the working buffer is an IELM | |
155 | buffer, distinct from the process buffer, then `***' gives the value in | |
156 | the working buffer, `*3' the value in the process buffer. | |
157 | The intended value is only accessible during IELM evaluation.") | |
158 | ||
813f532d RS |
159 | ;;; System variables |
160 | ||
161 | (defvar ielm-working-buffer nil | |
e848854a RS |
162 | "Buffer in which IELM sexps will be evaluated. |
163 | This variable is buffer-local.") | |
813f532d | 164 | |
690ec649 | 165 | (defvar ielm-header |
0a13146e | 166 | "*** Welcome to IELM *** Type (describe-mode) for help.\n" |
e848854a | 167 | "Message to display when IELM is started.") |
813f532d | 168 | |
61c11870 JB |
169 | (defvar ielm-map |
170 | (let ((map (make-sparse-keymap))) | |
6ef9aed8 | 171 | (define-key map "\t" 'ielm-tab) |
61c11870 | 172 | (define-key map "\C-m" 'ielm-return) |
04a19a79 | 173 | (define-key map "\e\C-m" 'ielm-return-for-effect) |
61c11870 JB |
174 | (define-key map "\C-j" 'ielm-send-input) |
175 | (define-key map "\e\C-x" 'eval-defun) ; for consistency with | |
51ef56c4 | 176 | (define-key map "\e\t" 'completion-at-point) ; lisp-interaction-mode |
61c11870 JB |
177 | ;; These bindings are from `lisp-mode-shared-map' -- can you inherit |
178 | ;; from more than one keymap?? | |
179 | (define-key map "\e\C-q" 'indent-sexp) | |
180 | (define-key map "\177" 'backward-delete-char-untabify) | |
181 | ;; Some convenience bindings for setting the working buffer | |
182 | (define-key map "\C-c\C-b" 'ielm-change-working-buffer) | |
183 | (define-key map "\C-c\C-f" 'ielm-display-working-buffer) | |
184 | (define-key map "\C-c\C-v" 'ielm-print-working-buffer) | |
185 | map) | |
186 | "Keymap for IELM mode.") | |
187 | (defvaralias 'inferior-emacs-lisp-mode-map 'ielm-map) | |
813f532d | 188 | |
fe1eb856 RS |
189 | (easy-menu-define ielm-menu ielm-map |
190 | "IELM mode menu." | |
191 | '("IELM" | |
192 | ["Change Working Buffer" ielm-change-working-buffer t] | |
193 | ["Display Working Buffer" ielm-display-working-buffer t] | |
194 | ["Print Working Buffer" ielm-print-working-buffer t])) | |
195 | ||
9d42eea3 | 196 | (defvar ielm-font-lock-keywords |
016b8f71 | 197 | '(("\\(^\\*\\*\\*[^*]+\\*\\*\\*\\)\\(.*$\\)" |
883212ce SM |
198 | (1 font-lock-comment-face) |
199 | (2 font-lock-constant-face))) | |
61c11870 | 200 | "Additional expressions to highlight in IELM buffers.") |
690ec649 | 201 | |
813f532d RS |
202 | ;;; Completion stuff |
203 | ||
6ef9aed8 SM |
204 | (defun ielm-tab () |
205 | "Indent or complete." | |
813f532d | 206 | (interactive) |
6ef9aed8 SM |
207 | (if (or (eq (preceding-char) ?\n) |
208 | (eq (char-syntax (preceding-char)) ?\s)) | |
209 | (ielm-indent-line) | |
210 | (completion-at-point))) | |
211 | ||
813f532d RS |
212 | |
213 | (defun ielm-complete-filename nil | |
e848854a | 214 | "Dynamically complete filename before point, if in a string." |
61c11870 | 215 | (when (nth 3 (parse-partial-sexp comint-last-input-start (point))) |
6ef9aed8 | 216 | (comint-filename-completion))) |
690ec649 | 217 | |
813f532d | 218 | (defun ielm-indent-line nil |
e848854a | 219 | "Indent the current line as Lisp code if it is not a prompt line." |
3250010d | 220 | (when (save-excursion (comint-bol) (bolp)) |
813f532d RS |
221 | (lisp-indent-line))) |
222 | ||
e848854a RS |
223 | ;;; Working buffer manipulation |
224 | ||
225 | (defun ielm-print-working-buffer nil | |
226 | "Print the current IELM working buffer's name in the echo area." | |
227 | (interactive) | |
228 | (message "The current working buffer is: %s" (buffer-name ielm-working-buffer))) | |
229 | ||
230 | (defun ielm-display-working-buffer nil | |
231 | "Display the current IELM working buffer. | |
232 | Don't forget that selecting that buffer will change its value of `point' | |
233 | to its value of `window-point'!" | |
234 | (interactive) | |
235 | (display-buffer ielm-working-buffer) | |
236 | (ielm-print-working-buffer)) | |
237 | ||
238 | (defun ielm-change-working-buffer (buf) | |
239 | "Change the current IELM working buffer to BUF. | |
240 | This is the buffer in which all sexps entered at the IELM prompt are | |
241 | evaluated. You can achieve the same effect with a call to | |
242 | `set-buffer' at the IELM prompt." | |
243 | (interactive "bSet working buffer to: ") | |
61c11870 JB |
244 | (let ((buffer (get-buffer buf))) |
245 | (if (and buffer (buffer-live-p buffer)) | |
04a19a79 | 246 | (setq ielm-working-buffer buffer) |
61c11870 | 247 | (error "No such buffer: %S" buf))) |
e848854a RS |
248 | (ielm-print-working-buffer)) |
249 | ||
813f532d RS |
250 | ;;; Other bindings |
251 | ||
04a19a79 | 252 | (defun ielm-return (&optional for-effect) |
e848854a RS |
253 | "Newline and indent, or evaluate the sexp before the prompt. |
254 | Complete sexps are evaluated; for incomplete sexps inserts a newline | |
255 | and indents. If however `ielm-dynamic-return' is nil, this always | |
256 | simply inserts a newline." | |
813f532d | 257 | (interactive) |
690ec649 SS |
258 | (if ielm-dynamic-return |
259 | (let ((state | |
04a19a79 DC |
260 | (save-excursion |
261 | (end-of-line) | |
262 | (parse-partial-sexp (ielm-pm) | |
263 | (point))))) | |
264 | (if (and (< (car state) 1) (not (nth 3 state))) | |
265 | (ielm-send-input for-effect) | |
266 | (when (and ielm-dynamic-multiline-inputs | |
267 | (save-excursion | |
268 | (beginning-of-line) | |
269 | (looking-at-p comint-prompt-regexp))) | |
270 | (save-excursion | |
271 | (goto-char (ielm-pm)) | |
272 | (newline 1))) | |
273 | (newline-and-indent))) | |
813f532d RS |
274 | (newline))) |
275 | ||
04a19a79 DC |
276 | (defun ielm-return-for-effect () |
277 | "Like `ielm-return', but do not print the result." | |
278 | (interactive) | |
279 | (ielm-return t)) | |
280 | ||
94aba130 RS |
281 | (defvar ielm-input) |
282 | ||
06b60517 | 283 | (defun ielm-input-sender (_proc input) |
690ec649 | 284 | ;; Just sets the variable ielm-input, which is in the scope of |
e848854a | 285 | ;; `ielm-send-input's call. |
813f532d RS |
286 | (setq ielm-input input)) |
287 | ||
04a19a79 | 288 | (defun ielm-send-input (&optional for-effect) |
e848854a | 289 | "Evaluate the Emacs Lisp expression after the prompt." |
813f532d | 290 | (interactive) |
04a19a79 DC |
291 | (let (ielm-input) ; set by ielm-input-sender |
292 | (comint-send-input) ; update history, markers etc. | |
293 | (ielm-eval-input ielm-input for-effect))) | |
813f532d RS |
294 | |
295 | ;;; Utility functions | |
296 | ||
6ad18d45 | 297 | (defun ielm-is-whitespace-or-comment (string) |
2ef180f7 | 298 | "Return non-nil if STRING is all whitespace or a comment." |
61c11870 JB |
299 | (or (string= string "") |
300 | (string-match-p "\\`[ \t\n]*\\(?:;.*\\)*\\'" string))) | |
813f532d | 301 | |
813f532d RS |
302 | ;;; Evaluation |
303 | ||
04a19a79 DC |
304 | (defun ielm-standard-output-impl (process) |
305 | "Return a function to use for `standard-output' while in ielm eval. | |
306 | The returned function takes one character as input. Passing nil | |
307 | to this function instead of a character flushes the output | |
308 | buffer. Passing t appends a terminating newline if the buffer is | |
309 | nonempty, then flushes the buffer." | |
310 | ;; Use an intermediate output buffer because doing redisplay for | |
311 | ;; each character we output is too expensive. Set up a flush timer | |
312 | ;; so that users don't have to wait for whole lines to appear before | |
313 | ;; seeing output. | |
314 | (let* ((output-buffer nil) | |
315 | (flush-timer nil) | |
316 | (flush-buffer | |
317 | (lambda () | |
318 | (comint-output-filter | |
319 | process | |
320 | (apply #'string (nreverse output-buffer))) | |
321 | (redisplay) | |
322 | (setf output-buffer nil) | |
323 | (when flush-timer | |
324 | (cancel-timer flush-timer) | |
325 | (setf flush-timer nil))))) | |
326 | (lambda (char) | |
327 | (let (flush-now) | |
328 | (cond ((and (eq char t) output-buffer) | |
329 | (push ?\n output-buffer) | |
330 | (setf flush-now t)) | |
331 | ((characterp char) | |
332 | (push char output-buffer))) | |
333 | (if flush-now | |
334 | (funcall flush-buffer) | |
335 | (unless flush-timer | |
336 | (setf flush-timer (run-with-timer 0.1 nil flush-buffer)))))))) | |
337 | ||
338 | (defun ielm-eval-input (input-string &optional for-effect) | |
06b60517 | 339 | "Evaluate the Lisp expression INPUT-STRING, and pretty-print the result." |
813f532d | 340 | ;; This is the function that actually `sends' the input to the |
e848854a | 341 | ;; `inferior Lisp process'. All comint-send-input does is works out |
813f532d RS |
342 | ;; what that input is. What this function does is evaluates that |
343 | ;; input and produces `output' which gets inserted into the buffer, | |
344 | ;; along with a new prompt. A better way of doing this might have | |
345 | ;; been to actually send the output to the `cat' process, and write | |
346 | ;; this as in output filter that converted sexps in the output | |
347 | ;; stream to their evaluated value. But that would have involved | |
348 | ;; more process coordination than I was happy to deal with. | |
04a19a79 DC |
349 | (let ((string input-string) ; input expression, as a string |
350 | form ; form to evaluate | |
351 | pos ; End posn of parse in string | |
352 | result ; Result, or error message | |
353 | error-type ; string, nil if no error | |
354 | (output "") ; result to display | |
355 | (wbuf ielm-working-buffer) ; current buffer after evaluation | |
356 | (pmark (ielm-pm))) | |
357 | (unless (ielm-is-whitespace-or-comment string) | |
61c11870 | 358 | (condition-case err |
04a19a79 DC |
359 | (let ((rout (read-from-string string))) |
360 | (setq form (car rout) | |
361 | pos (cdr rout))) | |
362 | (error (setq result (error-message-string err)) | |
363 | (setq error-type "Read error"))) | |
364 | (unless error-type | |
365 | ;; Make sure working buffer has not been killed | |
366 | (if (not (buffer-name ielm-working-buffer)) | |
367 | (setq result "Working buffer has been killed" | |
368 | error-type "IELM Error" | |
369 | wbuf (current-buffer)) | |
370 | (if (ielm-is-whitespace-or-comment (substring string pos)) | |
371 | ;; To correctly handle the ielm-local variables *, | |
372 | ;; ** and ***, we need a temporary buffer to be | |
373 | ;; current at entry to the inner of the next two let | |
374 | ;; forms. We need another temporary buffer to exit | |
375 | ;; that same let. To avoid problems, neither of | |
376 | ;; these buffers should be alive during the | |
377 | ;; evaluation of form. | |
378 | (let* ((*1 *) | |
379 | (*2 **) | |
380 | (*3 ***) | |
381 | (active-process (ielm-process)) | |
382 | (old-standard-output standard-output) | |
383 | new-standard-output | |
384 | ielm-temp-buffer) | |
385 | (set-match-data ielm-match-data) | |
386 | (save-excursion | |
387 | (with-temp-buffer | |
388 | (condition-case err | |
389 | (unwind-protect | |
390 | ;; The next let form creates default | |
391 | ;; bindings for *, ** and ***. But | |
392 | ;; these default bindings are | |
393 | ;; identical to the ielm-local | |
394 | ;; bindings. Hence, during the | |
395 | ;; evaluation of form, the | |
396 | ;; ielm-local values are going to be | |
397 | ;; used in all buffers except for | |
398 | ;; other ielm buffers, which override | |
399 | ;; them. Normally, the variables *1, | |
400 | ;; *2 and *3 also have default | |
401 | ;; bindings, which are not overridden. | |
402 | (let ((* *1) | |
403 | (** *2) | |
404 | (*** *3)) | |
405 | (when (eq standard-output t) | |
406 | (setf new-standard-output | |
407 | (ielm-standard-output-impl | |
408 | active-process)) | |
409 | (setf standard-output new-standard-output)) | |
410 | (kill-buffer (current-buffer)) | |
411 | (set-buffer wbuf) | |
412 | (setq result | |
413 | (eval form lexical-binding)) | |
414 | (setq wbuf (current-buffer)) | |
415 | (setq | |
416 | ielm-temp-buffer | |
417 | (generate-new-buffer " *ielm-temp*")) | |
418 | (set-buffer ielm-temp-buffer)) | |
419 | (when ielm-temp-buffer | |
420 | (kill-buffer ielm-temp-buffer)) | |
421 | (when (eq new-standard-output standard-output) | |
422 | (ignore-errors | |
423 | (funcall standard-output t)) | |
424 | (setf standard-output old-standard-output))) | |
425 | (error (setq result (error-message-string err)) | |
426 | (setq error-type "Eval error")) | |
427 | (quit (setq result "Quit during evaluation") | |
428 | (setq error-type "Eval error"))))) | |
429 | (setq ielm-match-data (match-data))) | |
430 | (setq error-type "IELM error") | |
431 | (setq result "More than one sexp in input")))) | |
61c11870 JB |
432 | |
433 | ;; If the eval changed the current buffer, mention it here | |
04a19a79 DC |
434 | (unless (eq wbuf ielm-working-buffer) |
435 | (message "current buffer is now: %s" wbuf) | |
436 | (setq ielm-working-buffer wbuf)) | |
437 | ||
438 | (goto-char pmark) | |
439 | (unless error-type | |
440 | (condition-case nil | |
441 | ;; Self-referential objects cause loops in the printer, so | |
442 | ;; trap quits here. May as well do errors, too | |
443 | (unless for-effect | |
b41594fd JL |
444 | (setq output (concat output (pp-to-string result) |
445 | (let ((str (eval-expression-print-format result))) | |
446 | (if str (propertize str 'font-lock-face 'shadow)))))) | |
04a19a79 DC |
447 | (error (setq error-type "IELM Error") |
448 | (setq result "Error during pretty-printing (bug in pp)")) | |
449 | (quit (setq error-type "IELM Error") | |
450 | (setq result "Quit during pretty-printing")))) | |
451 | (if error-type | |
452 | (progn | |
453 | (when ielm-noisy (ding)) | |
454 | (setq output (concat output "*** " error-type " *** ")) | |
455 | (setq output (concat output result))) | |
456 | ;; There was no error, so shift the *** values | |
457 | (setq *** **) | |
458 | (setq ** *) | |
459 | (setq * result)) | |
460 | (when (or (not for-effect) (not (equal output ""))) | |
461 | (setq output (concat output "\n")))) | |
462 | (setq output (concat output ielm-prompt-internal)) | |
463 | (comint-output-filter (ielm-process) output))) | |
813f532d RS |
464 | |
465 | ;;; Process and marker utilities | |
466 | ||
467 | (defun ielm-process nil | |
e848854a | 468 | ;; Return the current buffer's process. |
813f532d RS |
469 | (get-buffer-process (current-buffer))) |
470 | ||
471 | (defun ielm-pm nil | |
e848854a | 472 | ;; Return the process mark of the current buffer. |
813f532d RS |
473 | (process-mark (get-buffer-process (current-buffer)))) |
474 | ||
475 | (defun ielm-set-pm (pos) | |
e848854a | 476 | ;; Set the process mark in the current buffer to POS. |
813f532d RS |
477 | (set-marker (process-mark (get-buffer-process (current-buffer))) pos)) |
478 | ||
479 | ;;; Major mode | |
480 | ||
61c11870 | 481 | (define-derived-mode inferior-emacs-lisp-mode comint-mode "IELM" |
e848854a RS |
482 | "Major mode for interactively evaluating Emacs Lisp expressions. |
483 | Uses the interface provided by `comint-mode' (which see). | |
484 | ||
66f06793 SM |
485 | * \\<ielm-map>\\[ielm-send-input] evaluates the sexp following the prompt. There must be at most |
486 | one top level sexp per prompt. | |
813f532d | 487 | |
e848854a RS |
488 | * \\[ielm-return] inserts a newline and indents, or evaluates a |
489 | complete expression (but see variable `ielm-dynamic-return'). | |
490 | Inputs longer than one line are moved to the line following the | |
491 | prompt (but see variable `ielm-dynamic-multiline-inputs'). | |
492 | ||
04a19a79 DC |
493 | * \\[ielm-return-for-effect] works like `ielm-return', except |
494 | that it doesn't print the result of evaluating the input. This | |
495 | functionality is useful when forms would generate voluminous | |
496 | output. | |
497 | ||
d209d4a9 | 498 | * \\[completion-at-point] completes Lisp symbols (or filenames, within strings), |
e848854a | 499 | or indents the line if there is nothing to complete. |
813f532d | 500 | |
61c11870 JB |
501 | The current working buffer may be changed (with a call to `set-buffer', |
502 | or with \\[ielm-change-working-buffer]), and its value is preserved between successive | |
503 | evaluations. In this way, expressions may be evaluated in a different | |
504 | buffer than the *ielm* buffer. By default, its name is shown on the | |
505 | mode line; you can always display it with \\[ielm-print-working-buffer], or the buffer itself | |
506 | with \\[ielm-display-working-buffer]. | |
813f532d | 507 | |
5d9655bb RS |
508 | During evaluations, the values of the variables `*', `**', and `***' |
509 | are the results of the previous, second previous and third previous | |
510 | evaluations respectively. If the working buffer is another IELM | |
511 | buffer, then the values in the working buffer are used. The variables | |
512 | `*1', `*2' and `*3', yield the process buffer values. | |
513 | ||
04a19a79 DC |
514 | If, at the start of evaluation, `standard-output' is `t' (the |
515 | default), `standard-output' is set to a special function that | |
516 | causes output to be directed to the ielm buffer. | |
517 | `standard-output' is restored after evaluation unless explicitly | |
518 | set to a different value during evaluation. You can use (princ | |
519 | VALUE) or (pp VALUE) to write to the ielm buffer. | |
520 | ||
e848854a RS |
521 | Expressions evaluated by IELM are not subject to `debug-on-quit' or |
522 | `debug-on-error'. | |
813f532d | 523 | |
291cfc0c | 524 | The behavior of IELM may be customized with the following variables: |
0382cf8f | 525 | * To stop beeping on error, set `ielm-noisy' to nil. |
813f532d | 526 | * If you don't like the prompt, you can change it by setting `ielm-prompt'. |
759f960a LT |
527 | * If you do not like that the prompt is (by default) read-only, set |
528 | `ielm-prompt-read-only' to nil. | |
0382cf8f | 529 | * Set `ielm-dynamic-return' to nil for bindings like `lisp-interaction-mode'. |
813f532d RS |
530 | * Entry to this mode runs `comint-mode-hook' and `ielm-mode-hook' |
531 | (in that order). | |
532 | ||
0382cf8f | 533 | Customized bindings may be defined in `ielm-map', which currently contains: |
813f532d | 534 | \\{ielm-map}" |
61c11870 JB |
535 | :syntax-table emacs-lisp-mode-syntax-table |
536 | ||
813f532d | 537 | (setq comint-prompt-regexp (concat "^" (regexp-quote ielm-prompt))) |
85ab9f4e | 538 | (set (make-local-variable 'paragraph-separate) "\\'") |
61c11870 | 539 | (set (make-local-variable 'paragraph-start) comint-prompt-regexp) |
813f532d RS |
540 | (setq comint-input-sender 'ielm-input-sender) |
541 | (setq comint-process-echoes nil) | |
d209d4a9 | 542 | (set (make-local-variable 'completion-at-point-functions) |
6ef9aed8 SM |
543 | '(comint-replace-by-expanded-history |
544 | ielm-complete-filename lisp-completion-at-point)) | |
016b8f71 LT |
545 | (set (make-local-variable 'ielm-prompt-internal) ielm-prompt) |
546 | (set (make-local-variable 'comint-prompt-read-only) ielm-prompt-read-only) | |
e848854a | 547 | (setq comint-get-old-input 'ielm-get-old-input) |
61c11870 | 548 | (set (make-local-variable 'comint-completion-addsuffix) '("/" . "")) |
76364803 | 549 | (setq mode-line-process '(":%s on " (:eval (buffer-name ielm-working-buffer)))) |
fe1eb856 RS |
550 | ;; Useful for `hs-minor-mode'. |
551 | (setq-local comment-start ";") | |
a11463de | 552 | (setq-local comment-use-syntax t) |
813f532d | 553 | |
61c11870 JB |
554 | (set (make-local-variable 'indent-line-function) 'ielm-indent-line) |
555 | (set (make-local-variable 'ielm-working-buffer) (current-buffer)) | |
556 | (set (make-local-variable 'fill-paragraph-function) 'lisp-fill-paragraph) | |
813f532d | 557 | |
e848854a | 558 | ;; Value holders |
61c11870 JB |
559 | (set (make-local-variable '*) nil) |
560 | (set (make-local-variable '**) nil) | |
561 | (set (make-local-variable '***) nil) | |
565f89ec | 562 | (set (make-local-variable 'ielm-match-data) nil) |
813f532d | 563 | |
9d42eea3 | 564 | ;; font-lock support |
61c11870 JB |
565 | (set (make-local-variable 'font-lock-defaults) |
566 | '(ielm-font-lock-keywords nil nil ((?: . "w") (?- . "w") (?* . "w")))) | |
690ec649 | 567 | |
813f532d | 568 | ;; A dummy process to keep comint happy. It will never get any input |
20b13009 | 569 | (unless (comint-check-proc (current-buffer)) |
33a65176 JR |
570 | ;; Was cat, but on non-Unix platforms that might not exist, so |
571 | ;; use hexl instead, which is part of the Emacs distribution. | |
66f06793 | 572 | (condition-case nil |
04a19a79 | 573 | (start-process "ielm" (current-buffer) "hexl") |
66f06793 | 574 | (file-error (start-process "ielm" (current-buffer) "cat"))) |
e5927b52 | 575 | (set-process-query-on-exit-flag (ielm-process) nil) |
813f532d | 576 | (goto-char (point-max)) |
71296446 | 577 | |
20b13009 MB |
578 | ;; Lisp output can include raw characters that confuse comint's |
579 | ;; carriage control code. | |
580 | (set (make-local-variable 'comint-inhibit-carriage-motion) t) | |
581 | ||
813f532d RS |
582 | ;; Add a silly header |
583 | (insert ielm-header) | |
584 | (ielm-set-pm (point-max)) | |
85ab9f4e | 585 | (unless comint-use-prompt-regexp |
76364803 JB |
586 | (let ((inhibit-read-only t)) |
587 | (add-text-properties | |
588 | (point-min) (point-max) | |
589 | '(rear-nonsticky t field output inhibit-line-move-field-capture t)))) | |
016b8f71 | 590 | (comint-output-filter (ielm-process) ielm-prompt-internal) |
813f532d | 591 | (set-marker comint-last-input-start (ielm-pm)) |
61c11870 | 592 | (set-process-filter (get-buffer-process (current-buffer)) 'comint-output-filter))) |
813f532d | 593 | |
e848854a RS |
594 | (defun ielm-get-old-input nil |
595 | ;; Return the previous input surrounding point | |
596 | (save-excursion | |
597 | (beginning-of-line) | |
61c11870 | 598 | (unless (looking-at-p comint-prompt-regexp) |
e848854a RS |
599 | (re-search-backward comint-prompt-regexp)) |
600 | (comint-skip-prompt) | |
601 | (buffer-substring (point) (progn (forward-sexp 1) (point))))) | |
602 | ||
813f532d RS |
603 | ;;; User command |
604 | ||
e848854a | 605 | ;;;###autoload |
813f532d | 606 | (defun ielm nil |
e848854a | 607 | "Interactively evaluate Emacs Lisp expressions. |
04a19a79 DC |
608 | Switches to the buffer `*ielm*', or creates it if it does not exist. |
609 | See `inferior-emacs-lisp-mode' for details." | |
813f532d | 610 | (interactive) |
ee9cd72d LT |
611 | (let (old-point) |
612 | (unless (comint-check-proc "*ielm*") | |
613 | (with-current-buffer (get-buffer-create "*ielm*") | |
04a19a79 DC |
614 | (unless (zerop (buffer-size)) (setq old-point (point))) |
615 | (inferior-emacs-lisp-mode))) | |
37ac18a3 | 616 | (switch-to-buffer "*ielm*") |
ee9cd72d | 617 | (when old-point (push-mark old-point)))) |
813f532d | 618 | |
896546cd RS |
619 | (provide 'ielm) |
620 | ||
e848854a | 621 | ;;; ielm.el ends here |