emacs / lisp / thingatpt.el

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
;;; thingatpt.el --- get the `thing' at point

;; Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2000,
;;   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
;;   Free Software Foundation, Inc.

;; Author: Mike Williams <mikew@gopher.dosli.govt.nz>
;; Maintainer: FSF
;; Keywords: extensions, matching, mouse
;; Created: Thu Mar 28 13:48:23 1991

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This file provides routines for getting the "thing" at the location of
;; point, whatever that "thing" happens to be.  The "thing" is defined by
;; its beginning and end positions in the buffer.
;;
;; The function bounds-of-thing-at-point finds the beginning and end
;; positions by moving first forward to the end of the "thing", and then
;; backwards to the beginning.  By default, it uses the corresponding
;; forward-"thing" operator (eg. forward-word, forward-line).
;;
;; Special cases are allowed for using properties associated with the named
;; "thing":
;;
;;   forward-op		Function to call to skip forward over a "thing" (or
;;                      with a negative argument, backward).
;;
;;   beginning-op	Function to call to skip to the beginning of a "thing".
;;   end-op		Function to call to skip to the end of a "thing".
;;
;; Reliance on existing operators means that many `things' can be accessed
;; without further code:  eg.
;;     (thing-at-point 'line)
;;     (thing-at-point 'page)

;;; Code:

(provide 'thingatpt)

;; Basic movement

;;;###autoload
(defun forward-thing (thing &optional n)
  "Move forward to the end of the Nth next THING."
  (let ((forward-op (or (get thing 'forward-op)
			(intern-soft (format "forward-%s" thing)))))
    (if (functionp forward-op)
	(funcall forward-op (or n 1))
      (error "Can't determine how to move over a %s" thing))))

;; General routines

;;;###autoload
(defun bounds-of-thing-at-point (thing)
  "Determine the start and end buffer locations for the THING at point.
THING is a symbol which specifies the kind of syntactic entity you want.
Possibilities include `symbol', `list', `sexp', `defun', `filename', `url',
`email', `word', `sentence', `whitespace', `line', `page' and others.

See the file `thingatpt.el' for documentation on how to define
a symbol as a valid THING.

The value is a cons cell (START . END) giving the start and end positions
of the textual entity that was found."
  (if (get thing 'bounds-of-thing-at-point)
      (funcall (get thing 'bounds-of-thing-at-point))
    (let ((orig (point)))
      (condition-case nil
	  (save-excursion
	    ;; Try moving forward, then back.
            (funcall ;; First move to end.
             (or (get thing 'end-op)
                 (lambda () (forward-thing thing 1))))
            (funcall ;; Then move to beg.
             (or (get thing 'beginning-op)
                 (lambda () (forward-thing thing -1))))
	    (let ((beg (point)))
	      (if (not (and beg (> beg orig)))
		  ;; If that brings us all the way back to ORIG,
		  ;; it worked.  But END may not be the real end.
		  ;; So find the real end that corresponds to BEG.
		  (let ((real-end
			 (progn
			   (funcall
			    (or (get thing 'end-op)
                                (lambda () (forward-thing thing 1))))
			   (point))))
		    (if (and beg real-end (<= beg orig) (<= orig real-end))
			(cons beg real-end)))
		(goto-char orig)
		;; Try a second time, moving backward first and then forward,
		;; so that we can find a thing that ends at ORIG.
                (funcall ;; First, move to beg.
                 (or (get thing 'beginning-op)
                     (lambda () (forward-thing thing -1))))
                (funcall ;; Then move to end.
                 (or (get thing 'end-op)
                     (lambda () (forward-thing thing 1))))
		(let ((end (point))
                      (real-beg
		       (progn
			 (funcall
			  (or (get thing 'beginning-op)
                              (lambda () (forward-thing thing -1))))
			 (point))))
		  (if (and real-beg end (<= real-beg orig) (<= orig end))
		      (cons real-beg end))))))
	(error nil)))))

;;;###autoload
(defun thing-at-point (thing)
  "Return the THING at point.
THING is a symbol which specifies the kind of syntactic entity you want.
Possibilities include `symbol', `list', `sexp', `defun', `filename', `url',
`email', `word', `sentence', `whitespace', `line', `page' and others.

See the file `thingatpt.el' for documentation on how to define
a symbol as a valid THING."
  (if (get thing 'thing-at-point)
      (funcall (get thing 'thing-at-point))
    (let ((bounds (bounds-of-thing-at-point thing)))
      (if bounds
	  (buffer-substring (car bounds) (cdr bounds))))))

;; Go to beginning/end

(defun beginning-of-thing (thing)
  (let ((bounds (bounds-of-thing-at-point thing)))
    (or bounds (error "No %s here" thing))
    (goto-char (car bounds))))

(defun end-of-thing (thing)
  (let ((bounds (bounds-of-thing-at-point thing)))
    (or bounds (error "No %s here" thing))
    (goto-char (cdr bounds))))

;;  Special cases

;;  Lines

;; bolp will be false when you click on the last line in the buffer
;; and it has no final newline.

(put 'line 'beginning-op
     (lambda () (if (bolp) (forward-line -1) (beginning-of-line))))

;;  Sexps

(defun in-string-p ()
  (let ((orig (point)))
    (save-excursion
      (beginning-of-defun)
      (nth 3 (parse-partial-sexp (point) orig)))))

(defun end-of-sexp ()
  (let ((char-syntax (char-syntax (char-after))))
    (if (or (eq char-syntax ?\))
	    (and (eq char-syntax ?\") (in-string-p)))
	(forward-char 1)
      (forward-sexp 1))))

(put 'sexp 'end-op 'end-of-sexp)

(defun beginning-of-sexp ()
  (let ((char-syntax (char-syntax (char-before))))
    (if (or (eq char-syntax ?\()
	    (and (eq char-syntax ?\") (in-string-p)))
	(forward-char -1)
      (forward-sexp -1))))

(put 'sexp 'beginning-op 'beginning-of-sexp)

;;  Lists

(put 'list 'bounds-of-thing-at-point 'thing-at-point-bounds-of-list-at-point)

(defun thing-at-point-bounds-of-list-at-point ()
  (save-excursion
    (let ((opoint (point))
	  (beg (condition-case nil
		   (progn (up-list -1)
			  (point))
		 (error nil))))
      (condition-case nil
	  (if beg
	      (progn (forward-sexp)
		     (cons beg (point)))
	    ;; Are we are at the beginning of a top-level sexp?
	    (forward-sexp)
	    (let ((end (point)))
	      (backward-sexp)
	      (if (>= opoint (point))
		  (cons opoint end))))
	(error nil)))))

;;  Filenames and URLs  www.com/foo%32bar

(defvar thing-at-point-file-name-chars "-~/[:alnum:]_.${}#%,:"
  "Characters allowable in filenames.")

(put 'filename 'end-op
     (lambda ()
       (re-search-forward (concat "\\=[" thing-at-point-file-name-chars "]*")
			  nil t)))
(put 'filename 'beginning-op
     (lambda ()
       (if (re-search-backward (concat "[^" thing-at-point-file-name-chars "]")
			       nil t)
	   (forward-char)
	 (goto-char (point-min)))))

(defvar thing-at-point-url-path-regexp
  "[^]\t\n \"'<>[^`{}]*[^]\t\n \"'<>[^`{}.,;]+"
  "A regular expression probably matching the host and filename or e-mail part of a URL.")

(defvar thing-at-point-short-url-regexp
  (concat "[-A-Za-z0-9.]+" thing-at-point-url-path-regexp)
  "A regular expression probably matching a URL without an access scheme.
Hostname matching is stricter in this case than for
``thing-at-point-url-regexp''.")

(defvar thing-at-point-uri-schemes
  ;; Officials from http://www.iana.org/assignments/uri-schemes.html
  '("ftp://" "http://" "gopher://" "mailto:" "news:" "nntp:"
    "telnet://" "wais://" "file:/" "prospero:" "z39.50s:" "z39.50r:"
    "cid:" "mid:" "vemmi:" "service:" "imap:" "nfs:" "acap:" "rtsp:"
    "tip:" "pop:" "data:" "dav:" "opaquelocktoken:" "sip:" "tel:" "fax:"
    "modem:" "ldap:" "https://" "soap.beep:" "soap.beeps:" "urn:" "go:"
    "afs:" "tn3270:" "mailserver:"
    "crid:" "dict:" "dns:" "dtn:" "h323:" "im:" "info:" "ipp:"
    "iris.beep:" "mtqp:" "mupdate:" "pres:" "sips:" "snmp:" "tag:"
    "tftp:" "xmlrpc.beep:" "xmlrpc.beeps:" "xmpp:"
  ;; Compatibility
    "snews:" "irc:" "mms://" "mmsh://")
  "Uniform Resource Identifier (URI) Schemes.")

(defvar thing-at-point-url-regexp
  (concat "\\<\\(" (mapconcat 'identity thing-at-point-uri-schemes "\\|") "\\)"
          thing-at-point-url-path-regexp)
  "A regular expression probably matching a complete URL.")

(defvar thing-at-point-markedup-url-regexp
  "<URL:[^>]+>"
  "A regular expression matching a URL marked up per RFC1738.
This may contain whitespace (including newlines) .")

(put 'url 'bounds-of-thing-at-point 'thing-at-point-bounds-of-url-at-point)
(defun thing-at-point-bounds-of-url-at-point ()
  (let ((strip (thing-at-point-looking-at
			 thing-at-point-markedup-url-regexp))) ;; (url "") short
    (if (or strip
	    (thing-at-point-looking-at thing-at-point-url-regexp)
	    ;; Access scheme omitted?
	    ;; (setq short (thing-at-point-looking-at
	    ;;     	 thing-at-point-short-url-regexp))
            )
	(let ((beginning (match-beginning 0))
	      (end (match-end 0)))
	  (when strip
            (setq beginning (+ beginning 5))
            (setq end (- end 1)))
	  (cons beginning end)))))

(put 'url 'thing-at-point 'thing-at-point-url-at-point)
(defun thing-at-point-url-at-point ()
  "Return the URL around or before point.

Search backwards for the start of a URL ending at or after point.  If
no URL found, return nil.  The access scheme will be prepended if
absent: \"mailto:\" if the string contains \"@\", \"ftp://\" if it
starts with \"ftp\" and not \"ftp:/\", or \"http://\" by default."

  (let ((url "") short strip)
    (if (or (setq strip (thing-at-point-looking-at
			 thing-at-point-markedup-url-regexp))
	    (thing-at-point-looking-at thing-at-point-url-regexp)
	    ;; Access scheme omitted?
	    (setq short (thing-at-point-looking-at
			 thing-at-point-short-url-regexp)))
	(progn
	  (setq url (buffer-substring-no-properties (match-beginning 0)
						    (match-end 0)))
	  (and strip (setq url (substring url 5 -1))) ; Drop "<URL:" & ">"
	  ;; strip whitespace
	  (while (string-match "[ \t\n\r]+" url)
	    (setq url (replace-match "" t t url)))
	  (and short (setq url (concat (cond ((string-match "^[a-zA-Z]+:" url)
					       ;; already has a URL scheme.
					       "")
					     ((string-match "@" url)
                                              "mailto:")
					     ;; e.g. ftp.swiss... or ftp-swiss...
                                             ((string-match "^ftp" url)
                                              "ftp://")
                                             (t "http://"))
                                       url)))
	  (if (string-equal "" url)
	      nil
	    url)))))

;; The normal thingatpt mechanism doesn't work for complex regexps.
;; This should work for almost any regexp wherever we are in the
;; match.  To do a perfect job for any arbitrary regexp would mean
;; testing every position before point.  Regexp searches won't find
;; matches that straddle the start position so we search forwards once
;; and then back repeatedly and then back up a char at a time.

(defun thing-at-point-looking-at (regexp)
  "Return non-nil if point is in or just after a match for REGEXP.
Set the match data from the earliest such match ending at or after
point."
  (save-excursion
    (let ((old-point (point)) match)
      (and (looking-at regexp)
	   (>= (match-end 0) old-point)
	   (setq match (point)))
      ;; Search back repeatedly from end of next match.
      ;; This may fail if next match ends before this match does.
      (re-search-forward regexp nil 'limit)
      (while (and (re-search-backward regexp nil t)
		  (or (> (match-beginning 0) old-point)
		      (and (looking-at regexp)	; Extend match-end past search start
			   (>= (match-end 0) old-point)
			   (setq match (point))))))
      (if (not match) nil
	(goto-char match)
	;; Back up a char at a time in case search skipped
	;; intermediate match straddling search start pos.
	(while (and (not (bobp))
		    (progn (backward-char 1) (looking-at regexp))
		    (>= (match-end 0) old-point)
		    (setq match (point))))
	(goto-char match)
	(looking-at regexp)))))

(put 'url 'end-op
     (lambda ()
       (let ((bounds (thing-at-point-bounds-of-url-at-point)))
         (if bounds
             (goto-char (cdr bounds))
           (error "No URL here")))))
(put 'url 'beginning-op
     (lambda ()
       (let ((bounds (thing-at-point-bounds-of-url-at-point)))
         (if bounds
             (goto-char (car bounds))
           (error "No URL here")))))

;;   Email addresses
(defvar thing-at-point-email-regexp
  "<?[-+_.~a-zA-Z][-+_.~:a-zA-Z0-9]*@[-.a-zA-Z0-9]+>?"
  "A regular expression probably matching an email address.
This does not match the real name portion, only the address, optionally
with angle brackets.")

;; Haven't set 'forward-op on 'email nor defined 'forward-email' because
;; not sure they're actually needed, and URL seems to skip them too.
;; Note that (end-of-thing 'email) and (beginning-of-thing 'email)
;; work automagically, though.

(put 'email 'bounds-of-thing-at-point
     (lambda ()
       (let ((thing (thing-at-point-looking-at thing-at-point-email-regexp)))
         (if thing
             (let ((beginning (match-beginning 0))
                   (end (match-end 0)))
               (cons beginning end))))))

(put 'email 'thing-at-point
     (lambda ()
       (let ((boundary-pair (bounds-of-thing-at-point 'email)))
         (if boundary-pair
             (buffer-substring-no-properties
              (car boundary-pair) (cdr boundary-pair))))))

;;  Whitespace

(defun forward-whitespace (arg)
  (interactive "p")
  (if (natnump arg)
      (re-search-forward "[ \t]+\\|\n" nil 'move arg)
    (while (< arg 0)
      (if (re-search-backward "[ \t]+\\|\n" nil 'move)
	  (or (eq (char-after (match-beginning 0)) 10)
	      (skip-chars-backward " \t")))
      (setq arg (1+ arg)))))

;;  Buffer

(put 'buffer 'end-op (lambda () (goto-char (point-max))))
(put 'buffer 'beginning-op (lambda () (goto-char (point-min))))

;;  Symbols

(defun forward-symbol (arg)
  (interactive "p")
  (if (natnump arg)
      (re-search-forward "\\(\\sw\\|\\s_\\)+" nil 'move arg)
    (while (< arg 0)
      (if (re-search-backward "\\(\\sw\\|\\s_\\)+" nil 'move)
	  (skip-syntax-backward "w_"))
      (setq arg (1+ arg)))))

;;  Syntax blocks

(defun forward-same-syntax (&optional arg)
  (interactive "p")
  (while (< arg 0)
    (skip-syntax-backward
     (char-to-string (char-syntax (char-before))))
    (setq arg (1+ arg)))
  (while (> arg 0)
    (skip-syntax-forward (char-to-string (char-syntax (char-after))))
    (setq arg (1- arg))))

;;  Aliases

(defun word-at-point () (thing-at-point 'word))
(defun sentence-at-point () (thing-at-point 'sentence))

(defun read-from-whole-string (str)
  "Read a Lisp expression from STR.
Signal an error if the entire string was not used."
  (let* ((read-data (read-from-string str))
	 (more-left
	  (condition-case nil
	      ;; The call to `ignore' suppresses a compiler warning.
	      (progn (ignore (read-from-string (substring str (cdr read-data))))
		     t)
	    (end-of-file nil))))
    (if more-left
	(error "Can't read whole string")
      (car read-data))))

(defun form-at-point (&optional thing pred)
  (let ((sexp (condition-case nil
		  (read-from-whole-string (thing-at-point (or thing 'sexp)))
		(error nil))))
    (if (or (not pred) (funcall pred sexp)) sexp)))

;;;###autoload
(defun sexp-at-point ()
  "Return the sexp at point, or nil if none is found."
  (form-at-point 'sexp))
;;;###autoload
(defun symbol-at-point ()
  "Return the symbol at point, or nil if none is found."
  (let ((thing (thing-at-point 'symbol)))
    (if thing (intern thing))))
;;;###autoload
(defun number-at-point ()
  "Return the number at point, or nil if none is found."
  (form-at-point 'sexp 'numberp))
;;;###autoload
(defun list-at-point ()
  "Return the Lisp list at point, or nil if none is found."
  (form-at-point 'list 'listp))

;; arch-tag: bb65a163-dae2-4055-aedc-fe11f497f698
;;; thingatpt.el ends here
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.