1;;; thingatpt.el --- get the `thing' at point 2 3;; Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2000, 4;; 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Mike Williams <mikew@gopher.dosli.govt.nz> 7;; Maintainer: FSF 8;; Keywords: extensions, matching, mouse 9;; Created: Thu Mar 28 13:48:23 1991 10 11;; This file is part of GNU Emacs. 12 13;; GNU Emacs is free software; you can redistribute it and/or modify 14;; it under the terms of the GNU General Public License as published by 15;; the Free Software Foundation; either version 2, or (at your option) 16;; any later version. 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;;; Commentary: 24 25;; This file provides routines for getting the "thing" at the location of 26;; point, whatever that "thing" happens to be. The "thing" is defined by 27;; its beginning and end positions in the buffer. 28;; 29;; The function bounds-of-thing-at-point finds the beginning and end 30;; positions by moving first forward to the end of the "thing", and then 31;; backwards to the beginning. By default, it uses the corresponding 32;; forward-"thing" operator (eg. forward-word, forward-line). 33;; 34;; Special cases are allowed for using properties associated with the named 35;; "thing": 36;; 37;; forward-op Function to call to skip forward over a "thing" (or 38;; with a negative argument, backward). 39;; 40;; beginning-op Function to call to skip to the beginning of a "thing". 41;; end-op Function to call to skip to the end of a "thing". 42;; 43;; Reliance on existing operators means that many `things' can be accessed 44;; without further code: eg. 45;; (thing-at-point 'line) 46;; (thing-at-point 'page) 47 48;;; Code: 49 50(provide 'thingatpt) 51 52;; Basic movement 53 54;;;###autoload 55(defun forward-thing (thing &optional n) 56 "Move forward to the end of the Nth next THING." 57 (let ((forward-op (or (get thing 'forward-op) 58 (intern-soft (format "forward-%s" thing))))) 59 (if (functionp forward-op) 60 (funcall forward-op (or n 1)) 61 (error "Can't determine how to move over a %s" thing)))) 62 63;; General routines 64 65;;;###autoload 66(defun bounds-of-thing-at-point (thing) 67 "Determine the start and end buffer locations for the THING at point. 68THING is a symbol which specifies the kind of syntactic entity you want. 69Possibilities include `symbol', `list', `sexp', `defun', `filename', `url', 70`word', `sentence', `whitespace', `line', `page' and others. 71 72See the file `thingatpt.el' for documentation on how to define 73a symbol as a valid THING. 74 75The value is a cons cell (START . END) giving the start and end positions 76of the textual entity that was found." 77 (if (get thing 'bounds-of-thing-at-point) 78 (funcall (get thing 'bounds-of-thing-at-point)) 79 (let ((orig (point))) 80 (condition-case nil 81 (save-excursion 82 ;; Try moving forward, then back. 83 (funcall ;; First move to end. 84 (or (get thing 'end-op) 85 (lambda () (forward-thing thing 1)))) 86 (funcall ;; Then move to beg. 87 (or (get thing 'beginning-op) 88 (lambda () (forward-thing thing -1)))) 89 (let ((beg (point))) 90 (if (not (and beg (> beg orig))) 91 ;; If that brings us all the way back to ORIG, 92 ;; it worked. But END may not be the real end. 93 ;; So find the real end that corresponds to BEG. 94 (let ((real-end 95 (progn 96 (funcall 97 (or (get thing 'end-op) 98 (lambda () (forward-thing thing 1)))) 99 (point)))) 100 (if (and beg real-end (<= beg orig) (<= orig real-end)) 101 (cons beg real-end))) 102 (goto-char orig) 103 ;; Try a second time, moving backward first and then forward, 104 ;; so that we can find a thing that ends at ORIG. 105 (funcall ;; First, move to beg. 106 (or (get thing 'beginning-op) 107 (lambda () (forward-thing thing -1)))) 108 (funcall ;; Then move to end. 109 (or (get thing 'end-op) 110 (lambda () (forward-thing thing 1)))) 111 (let ((end (point)) 112 (real-beg 113 (progn 114 (funcall 115 (or (get thing 'beginning-op) 116 (lambda () (forward-thing thing -1)))) 117 (point)))) 118 (if (and real-beg end (<= real-beg orig) (<= orig end)) 119 (cons real-beg end)))))) 120 (error nil))))) 121 122;;;###autoload 123(defun thing-at-point (thing) 124 "Return the THING at point. 125THING is a symbol which specifies the kind of syntactic entity you want. 126Possibilities include `symbol', `list', `sexp', `defun', `filename', `url', 127`word', `sentence', `whitespace', `line', `page' and others. 128 129See the file `thingatpt.el' for documentation on how to define 130a symbol as a valid THING." 131 (if (get thing 'thing-at-point) 132 (funcall (get thing 'thing-at-point)) 133 (let ((bounds (bounds-of-thing-at-point thing))) 134 (if bounds 135 (buffer-substring (car bounds) (cdr bounds)))))) 136 137;; Go to beginning/end 138 139(defun beginning-of-thing (thing) 140 (let ((bounds (bounds-of-thing-at-point thing))) 141 (or bounds (error "No %s here" thing)) 142 (goto-char (car bounds)))) 143 144(defun end-of-thing (thing) 145 (let ((bounds (bounds-of-thing-at-point thing))) 146 (or bounds (error "No %s here" thing)) 147 (goto-char (cdr bounds)))) 148 149;; Special cases 150 151;; Lines 152 153;; bolp will be false when you click on the last line in the buffer 154;; and it has no final newline. 155 156(put 'line 'beginning-op 157 (lambda () (if (bolp) (forward-line -1) (beginning-of-line)))) 158 159;; Sexps 160 161(defun in-string-p () 162 (let ((orig (point))) 163 (save-excursion 164 (beginning-of-defun) 165 (nth 3 (parse-partial-sexp (point) orig))))) 166 167(defun end-of-sexp () 168 (let ((char-syntax (char-syntax (char-after (point))))) 169 (if (or (eq char-syntax ?\)) 170 (and (eq char-syntax ?\") (in-string-p))) 171 (forward-char 1) 172 (forward-sexp 1)))) 173 174(put 'sexp 'end-op 'end-of-sexp) 175 176(defun beginning-of-sexp () 177 (let ((char-syntax (char-syntax (char-before (point))))) 178 (if (or (eq char-syntax ?\() 179 (and (eq char-syntax ?\") (in-string-p))) 180 (forward-char -1) 181 (forward-sexp -1)))) 182 183(put 'sexp 'beginning-op 'beginning-of-sexp) 184 185;; Lists 186 187(put 'list 'end-op (lambda () (up-list 1))) 188(put 'list 'beginning-op 'backward-sexp) 189 190;; Filenames and URLs www.com/foo%32bar 191 192(defvar thing-at-point-file-name-chars "-~/[:alnum:]_.${}#%,:" 193 "Characters allowable in filenames.") 194 195(put 'filename 'end-op 196 (lambda () 197 (re-search-forward (concat "\\=[" thing-at-point-file-name-chars "]*") 198 nil t))) 199(put 'filename 'beginning-op 200 (lambda () 201 (if (re-search-backward (concat "[^" thing-at-point-file-name-chars "]") 202 nil t) 203 (forward-char) 204 (goto-char (point-min))))) 205 206(defvar thing-at-point-url-path-regexp 207 "[^]\t\n \"'()<>[^`{}]*[^]\t\n \"'()<>[^`{}.,;]+" 208 "A regular expression probably matching the host and filename or e-mail part of a URL.") 209 210(defvar thing-at-point-short-url-regexp 211 (concat "[-A-Za-z0-9.]+" thing-at-point-url-path-regexp) 212 "A regular expression probably matching a URL without an access scheme. 213Hostname matching is stricter in this case than for 214``thing-at-point-url-regexp''.") 215 216(defvar thing-at-point-uri-schemes 217 ;; Officials from http://www.iana.org/assignments/uri-schemes.html 218 '("ftp://" "http://" "gopher://" "mailto:" "news:" "nntp:" 219 "telnet://" "wais://" "file:/" "prospero:" "z39.50s:" "z39.50r:" 220 "cid:" "mid:" "vemmi:" "service:" "imap:" "nfs:" "acap:" "rtsp:" 221 "tip:" "pop:" "data:" "dav:" "opaquelocktoken:" "sip:" "tel:" "fax:" 222 "modem:" "ldap:" "https://" "soap.beep:" "soap.beeps:" "urn:" "go:" 223 "afs:" "tn3270:" "mailserver:" 224 "crid:" "dict:" "dns:" "dtn:" "h323:" "im:" "info:" "ipp:" 225 "iris.beep:" "mtqp:" "mupdate:" "pres:" "sips:" "snmp:" "tag:" 226 "tftp:" "xmlrpc.beep:" "xmlrpc.beeps:" "xmpp:" 227 ;; Compatibility 228 "snews:" "irc:" "mms://" "mmsh://") 229 "Uniform Resource Identifier (URI) Schemes.") 230 231(defvar thing-at-point-url-regexp 232 (concat "\\<\\(" (mapconcat 'identity thing-at-point-uri-schemes "\\|") "\\)" 233 thing-at-point-url-path-regexp) 234 "A regular expression probably matching a complete URL.") 235 236(defvar thing-at-point-markedup-url-regexp 237 "<URL:[^>]+>" 238 "A regular expression matching a URL marked up per RFC1738. 239This may contain whitespace (including newlines) .") 240 241(put 'url 'bounds-of-thing-at-point 'thing-at-point-bounds-of-url-at-point) 242(defun thing-at-point-bounds-of-url-at-point () 243 (let ((strip (thing-at-point-looking-at 244 thing-at-point-markedup-url-regexp))) ;; (url "") short 245 (if (or strip 246 (thing-at-point-looking-at thing-at-point-url-regexp) 247 ;; Access scheme omitted? 248 ;; (setq short (thing-at-point-looking-at 249 ;; thing-at-point-short-url-regexp)) 250 ) 251 (let ((beginning (match-beginning 0)) 252 (end (match-end 0))) 253 (when strip 254 (setq beginning (+ beginning 5)) 255 (setq end (- end 1))) 256 (cons beginning end))))) 257 258(put 'url 'thing-at-point 'thing-at-point-url-at-point) 259(defun thing-at-point-url-at-point () 260 "Return the URL around or before point. 261 262Search backwards for the start of a URL ending at or after point. If 263no URL found, return nil. The access scheme will be prepended if 264absent: \"mailto:\" if the string contains \"@\", \"ftp://\" if it 265starts with \"ftp\" and not \"ftp:/\", or \"http://\" by default." 266 267 (let ((url "") short strip) 268 (if (or (setq strip (thing-at-point-looking-at 269 thing-at-point-markedup-url-regexp)) 270 (thing-at-point-looking-at thing-at-point-url-regexp) 271 ;; Access scheme omitted? 272 (setq short (thing-at-point-looking-at 273 thing-at-point-short-url-regexp))) 274 (progn 275 (setq url (buffer-substring-no-properties (match-beginning 0) 276 (match-end 0))) 277 (and strip (setq url (substring url 5 -1))) ; Drop "<URL:" & ">" 278 ;; strip whitespace 279 (while (string-match "[ \t\n\r]+" url) 280 (setq url (replace-match "" t t url))) 281 (and short (setq url (concat (cond ((string-match "^[a-zA-Z]+:" url) 282 ;; already has a URL scheme. 283 "") 284 ((string-match "@" url) 285 "mailto:") 286 ;; e.g. ftp.swiss... or ftp-swiss... 287 ((string-match "^ftp" url) 288 "ftp://") 289 (t "http://")) 290 url))) 291 (if (string-equal "" url) 292 nil 293 url))))) 294 295;; The normal thingatpt mechanism doesn't work for complex regexps. 296;; This should work for almost any regexp wherever we are in the 297;; match. To do a perfect job for any arbitrary regexp would mean 298;; testing every position before point. Regexp searches won't find 299;; matches that straddle the start position so we search forwards once 300;; and then back repeatedly and then back up a char at a time. 301 302(defun thing-at-point-looking-at (regexp) 303 "Return non-nil if point is in or just after a match for REGEXP. 304Set the match data from the earliest such match ending at or after 305point." 306 (save-excursion 307 (let ((old-point (point)) match) 308 (and (looking-at regexp) 309 (>= (match-end 0) old-point) 310 (setq match (point))) 311 ;; Search back repeatedly from end of next match. 312 ;; This may fail if next match ends before this match does. 313 (re-search-forward regexp nil 'limit) 314 (while (and (re-search-backward regexp nil t) 315 (or (> (match-beginning 0) old-point) 316 (and (looking-at regexp) ; Extend match-end past search start 317 (>= (match-end 0) old-point) 318 (setq match (point)))))) 319 (if (not match) nil 320 (goto-char match) 321 ;; Back up a char at a time in case search skipped 322 ;; intermediate match straddling search start pos. 323 (while (and (not (bobp)) 324 (progn (backward-char 1) (looking-at regexp)) 325 (>= (match-end 0) old-point) 326 (setq match (point)))) 327 (goto-char match) 328 (looking-at regexp))))) 329 330(put 'url 'end-op 331 (lambda () 332 (let ((bounds (thing-at-point-bounds-of-url-at-point))) 333 (if bounds 334 (goto-char (cdr bounds)) 335 (error "No URL here"))))) 336(put 'url 'beginning-op 337 (lambda () 338 (let ((bounds (thing-at-point-bounds-of-url-at-point))) 339 (if bounds 340 (goto-char (car bounds)) 341 (error "No URL here"))))) 342 343;; Whitespace 344 345(defun forward-whitespace (arg) 346 (interactive "p") 347 (if (natnump arg) 348 (re-search-forward "[ \t]+\\|\n" nil 'move arg) 349 (while (< arg 0) 350 (if (re-search-backward "[ \t]+\\|\n" nil 'move) 351 (or (eq (char-after (match-beginning 0)) 10) 352 (skip-chars-backward " \t"))) 353 (setq arg (1+ arg))))) 354 355;; Buffer 356 357(put 'buffer 'end-op (lambda () (goto-char (point-max)))) 358(put 'buffer 'beginning-op (lambda () (goto-char (point-min)))) 359 360;; Symbols 361 362(defun forward-symbol (arg) 363 (interactive "p") 364 (if (natnump arg) 365 (re-search-forward "\\(\\sw\\|\\s_\\)+" nil 'move arg) 366 (while (< arg 0) 367 (if (re-search-backward "\\(\\sw\\|\\s_\\)+" nil 'move) 368 (skip-syntax-backward "w_")) 369 (setq arg (1+ arg))))) 370 371;; Syntax blocks 372 373(defun forward-same-syntax (&optional arg) 374 (interactive "p") 375 (while (< arg 0) 376 (skip-syntax-backward 377 (char-to-string (char-syntax (char-after (1- (point)))))) 378 (setq arg (1+ arg))) 379 (while (> arg 0) 380 (skip-syntax-forward (char-to-string (char-syntax (char-after (point))))) 381 (setq arg (1- arg)))) 382 383;; Aliases 384 385(defun word-at-point () (thing-at-point 'word)) 386(defun sentence-at-point () (thing-at-point 'sentence)) 387 388(defun read-from-whole-string (str) 389 "Read a Lisp expression from STR. 390Signal an error if the entire string was not used." 391 (let* ((read-data (read-from-string str)) 392 (more-left 393 (condition-case nil 394 ;; The call to `ignore' suppresses a compiler warning. 395 (progn (ignore (read-from-string (substring str (cdr read-data)))) 396 t) 397 (end-of-file nil)))) 398 (if more-left 399 (error "Can't read whole string") 400 (car read-data)))) 401 402(defun form-at-point (&optional thing pred) 403 (let ((sexp (condition-case nil 404 (read-from-whole-string (thing-at-point (or thing 'sexp))) 405 (error nil)))) 406 (if (or (not pred) (funcall pred sexp)) sexp))) 407 408;;;###autoload 409(defun sexp-at-point () (form-at-point 'sexp)) 410;;;###autoload 411(defun symbol-at-point () 412 (let ((thing (thing-at-point 'symbol))) 413 (if thing (intern thing)))) 414;;;###autoload 415(defun number-at-point () (form-at-point 'sexp 'numberp)) 416;;;###autoload 417(defun list-at-point () (form-at-point 'list 'listp)) 418 419;; arch-tag: bb65a163-dae2-4055-aedc-fe11f497f698 420;;; thingatpt.el ends here 421