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;;; thingatpt.el --- get the `thing' at point
;; Copyright (C) 1991-1998, 2000-2015 Free Software Foundation, Inc.
;; Author: Mike Williams <mikew@gopher.dosli.govt.nz>
;; Maintainer: emacs-devel@gnu.org
;; 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.
THING should be a symbol specifying a type of syntactic entity.
Possibilities include `symbol', `list', `sexp', `defun',
`filename', `url', `email', `word', `sentence', `whitespace',
`line', and `page'."
(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 should be a symbol specifying a type of syntactic entity.
Possibilities include `symbol', `list', `sexp', `defun',
`filename', `url', `email', `word', `sentence', `whitespace',
`line', and `page'.
See the file `thingatpt.el' for documentation on how to define a
valid THING.
Return a cons cell (START . END) giving the start and end
positions of the thing found."
(if (get thing 'bounds-of-thing-at-point)
(funcall (get thing 'bounds-of-thing-at-point))
(let ((orig (point)))
(ignore-errors
(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 (<= 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.
;; FIXME: in which cases can `real-end' differ from `end'?
(let ((real-end
(progn
(funcall
(or (get thing 'end-op)
(lambda () (forward-thing thing 1))))
(point))))
(when (and (<= orig real-end) (< beg 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 orig) (<= orig end) (< real-beg end))
(cons real-beg end))))))))))
;;;###autoload
(defun thing-at-point (thing &optional no-properties)
"Return the THING at point.
THING should be a symbol specifying a type of syntactic entity.
Possibilities include `symbol', `list', `sexp', `defun',
`filename', `url', `email', `word', `sentence', `whitespace',
`line', `number', and `page'.
When the optional argument NO-PROPERTIES is non-nil,
strip text properties from the return value.
See the file `thingatpt.el' for documentation on how to define
a symbol as a valid THING."
(let ((text
(if (get thing 'thing-at-point)
(funcall (get thing 'thing-at-point))
(let ((bounds (bounds-of-thing-at-point thing)))
(when bounds
(buffer-substring (car bounds) (cdr bounds)))))))
(when (and text no-properties)
(set-text-properties 0 (length text) nil text))
text))
;; Go to beginning/end
(defun beginning-of-thing (thing)
"Move point to the beginning of THING.
The bounds of THING are determined by `bounds-of-thing-at-point'."
(let ((bounds (bounds-of-thing-at-point thing)))
(or bounds (error "No %s here" thing))
(goto-char (car bounds))))
(defun end-of-thing (thing)
"Move point to the end of THING.
The bounds of THING are determined by `bounds-of-thing-at-point'."
(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 ()
"Return non-nil if point is in a string.
\[This is an internal function.]"
(let ((orig (point)))
(save-excursion
(beginning-of-defun)
(nth 3 (parse-partial-sexp (point) orig)))))
(defun end-of-sexp ()
"Move point to the end of the current sexp.
\[This is an internal function.]"
(let ((char-syntax (syntax-after (point))))
(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 ()
"Move point to the beginning of the current sexp.
\[This is an internal function.]"
(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 ()
"Return the bounds of the list at point.
\[Internal function used by `bounds-of-thing-at-point'.]"
(save-excursion
(let ((opoint (point))
(beg (ignore-errors
(up-list -1)
(point))))
(ignore-errors
(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))))))))
;; Defuns
(put 'defun 'beginning-op 'beginning-of-defun)
(put 'defun 'end-op 'end-of-defun)
(put 'defun 'forward-op 'end-of-defun)
;; Filenames
(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)))))
;; URIs
(defvar thing-at-point-beginning-of-url-regexp nil
"Regexp matching the beginning of a well-formed URI.
If nil, construct the regexp from `thing-at-point-uri-schemes'.")
(defvar thing-at-point-url-path-regexp
"[^]\t\n \"'<>[^`{}]*[^]\t\n \"'<>[^`{}.,;]+"
"Regexp matching the host and filename or e-mail part of a URL.")
(defvar thing-at-point-short-url-regexp
(concat "[-A-Za-z0-9]+\\.[-A-Za-z0-9.]+" thing-at-point-url-path-regexp)
"Regexp matching a URI without a scheme component.")
(defvar thing-at-point-uri-schemes
;; Officials from http://www.iana.org/assignments/uri-schemes.html
'("aaa://" "about:" "acap://" "apt:" "bzr://" "bzr+ssh://"
"attachment:/" "chrome://" "cid:" "content://" "crid://" "cvs://"
"data:" "dav:" "dict://" "doi:" "dns:" "dtn:" "feed:" "file:/"
"finger://" "fish://" "ftp://" "geo:" "git://" "go:" "gopher://"
"h323:" "http://" "https://" "im:" "imap://" "info:" "ipp:"
"irc://" "irc6://" "ircs://" "iris.beep:" "jar:" "ldap://"
"ldaps://" "mailto:" "mid:" "mtqp://" "mupdate://" "news:"
"nfs://" "nntp://" "opaquelocktoken:" "pop://" "pres:"
"resource://" "rmi://" "rsync://" "rtsp://" "rtspu://" "service:"
"sftp://" "sip:" "sips:" "smb://" "sms:" "snmp://" "soap.beep://"
"soap.beeps://" "ssh://" "svn://" "svn+ssh://" "tag:" "tel:"
"telnet://" "tftp://" "tip://" "tn3270://" "udp://" "urn:"
"uuid:" "vemmi://" "webcal://" "xri://" "xmlrpc.beep://"
"xmlrpc.beeps://" "z39.50r://" "z39.50s://" "xmpp:"
;; Compatibility
"fax:" "mms://" "mmsh://" "modem:" "prospero:" "snews:"
"wais://")
"List of URI schemes recognized by `thing-at-point-url-at-point'.
Each string in this list should correspond to the start of a
URI's scheme component, up to and including the trailing // if
the scheme calls for that to be present.")
(defvar thing-at-point-markedup-url-regexp "<URL:\\([^<>\n]+\\)>"
"Regexp matching a URL marked up per RFC1738.
This kind of markup was formerly recommended as a way to indicate
URIs, but as of RFC 3986 it is no longer recommended.
Subexpression 1 should contain the delimited URL.")
(defvar thing-at-point-newsgroup-regexp
"\\`[[:lower:]]+\\.[-+[:lower:]_0-9.]+\\'"
"Regexp matching a newsgroup name.")
(defvar thing-at-point-newsgroup-heads
'("alt" "comp" "gnu" "misc" "news" "sci" "soc" "talk")
"Used by `thing-at-point-newsgroup-p' if gnus is not running.")
(defvar thing-at-point-default-mail-uri-scheme "mailto"
"Default scheme for ill-formed URIs that look like <foo@example.com>.
If nil, do not give such URIs a scheme.")
(put 'url 'bounds-of-thing-at-point 'thing-at-point-bounds-of-url-at-point)
(defun thing-at-point-bounds-of-url-at-point (&optional lax)
"Return a cons cell containing the start and end of the URI at point.
Try to find a URI using `thing-at-point-markedup-url-regexp'.
If that fails, try with `thing-at-point-beginning-of-url-regexp'.
If that also fails, and optional argument LAX is non-nil, return
the bounds of a possible ill-formed URI (one lacking a scheme)."
;; Look for the old <URL:foo> markup. If found, use it.
(or (thing-at-point--bounds-of-markedup-url)
;; Otherwise, find the bounds within which a URI may exist. The
;; method is similar to `ffap-string-at-point'. Note that URIs
;; may contain parentheses but may not contain spaces (RFC3986).
(let* ((allowed-chars "--:=&?$+@-Z_[:alpha:]~#,%;*()!'")
(skip-before "^[0-9a-zA-Z]")
(skip-after ":;.,!?")
(pt (point))
(beg (save-excursion
(skip-chars-backward allowed-chars)
(skip-chars-forward skip-before pt)
(point)))
(end (save-excursion
(skip-chars-forward allowed-chars)
(skip-chars-backward skip-after pt)
(point))))
(or (thing-at-point--bounds-of-well-formed-url beg end pt)
(if lax (cons beg end))))))
(defun thing-at-point--bounds-of-markedup-url ()
(when thing-at-point-markedup-url-regexp
(let ((case-fold-search t)
(pt (point))
(beg (line-beginning-position))
(end (line-end-position))
found)
(save-excursion
(goto-char beg)
(while (and (not found)
(<= (point) pt)
(< (point) end))
(and (re-search-forward thing-at-point-markedup-url-regexp
end 1)
(> (point) pt)
(setq found t))))
(if found
(cons (match-beginning 1) (match-end 1))))))
(defun thing-at-point--bounds-of-well-formed-url (beg end _pt)
(save-excursion
(goto-char beg)
(let (url-beg paren-end regexp)
(save-restriction
(narrow-to-region beg end)
;; The scheme component must either match at BEG, or have no
;; other alphanumerical ASCII characters before it.
(setq regexp (concat "\\(?:\\`\\|[^a-zA-Z0-9]\\)\\("
(or thing-at-point-beginning-of-url-regexp
(regexp-opt thing-at-point-uri-schemes))
"\\)"))
(and (re-search-forward regexp end t)
;; URI must have non-empty contents.
(< (point) end)
(setq url-beg (match-beginning 1))))
(when url-beg
;; If there is an open paren before the URI, truncate to the
;; matching close paren.
(and (> url-beg (point-min))
(eq (car-safe (syntax-after (1- url-beg))) 4)
(save-restriction
(narrow-to-region (1- url-beg) (min end (point-max)))
(setq paren-end (ignore-errors
(scan-lists (1- url-beg) 1 0))))
(not (blink-matching-check-mismatch (1- url-beg) paren-end))
(setq end (1- paren-end)))
(cons url-beg end)))))
(put 'url 'thing-at-point 'thing-at-point-url-at-point)
(defun thing-at-point-url-at-point (&optional lax bounds)
"Return the URL around or before point.
If no URL is found, return nil.
If optional argument LAX is non-nil, look for URLs that are not
well-formed, such as foo@bar or <nobody>.
If optional arguments BOUNDS are non-nil, it should be a cons
cell of the form (START . END), containing the beginning and end
positions of the URI. Otherwise, these positions are detected
automatically from the text around point.
If the scheme component is absent, either because a URI delimited
with <url:...> lacks one, or because an ill-formed URI was found
with LAX or BEG and END, try to add a scheme in the returned URI.
The scheme is chosen heuristically: \"mailto:\" if the address
looks like an email address, \"ftp://\" if it starts with
\"ftp\", etc."
(unless bounds
(setq bounds (thing-at-point-bounds-of-url-at-point lax)))
(when (and bounds (< (car bounds) (cdr bounds)))
(let ((str (buffer-substring-no-properties (car bounds) (cdr bounds))))
;; If there is no scheme component, try to add one.
(unless (string-match "\\`[a-zA-Z][-a-zA-Z0-9+.]*:" str)
(or
;; If the URI has the form <foo@bar>, treat it according to
;; `thing-at-point-default-mail-uri-scheme'. If there are
;; no angle brackets, it must be mailto.
(when (string-match "\\`[^:</>@]+@[-.0-9=&?$+A-Z_a-z~#,%;*]" str)
(let ((scheme (if (and (eq (char-before (car bounds)) ?<)
(eq (char-after (cdr bounds)) ?>))
thing-at-point-default-mail-uri-scheme
"mailto")))
(if scheme
(setq str (concat scheme ":" str)))))
;; If the string is like <FOO>, where FOO is an existing user
;; name on the system, treat that as an email address.
(and (string-match "\\`[[:alnum:]]+\\'" str)
(eq (char-before (car bounds)) ?<)
(eq (char-after (cdr bounds)) ?>)
(not (string-match "~" (expand-file-name (concat "~" str))))
(setq str (concat "mailto:" str)))
;; If it looks like news.example.com, treat it as news.
(if (thing-at-point-newsgroup-p str)
(setq str (concat "news:" str)))
;; If it looks like ftp.example.com. treat it as ftp.
(if (string-match "\\`ftp\\." str)
(setq str (concat "ftp://" str)))
;; If it looks like www.example.com. treat it as http.
(if (string-match "\\`www\\." str)
(setq str (concat "http://" str)))
;; Otherwise, it just isn't a URI.
(setq str nil)))
str)))
(defun thing-at-point-newsgroup-p (string)
"Return STRING if it looks like a newsgroup name, else nil."
(and
(string-match thing-at-point-newsgroup-regexp string)
(let ((htbs '(gnus-active-hashtb gnus-newsrc-hashtb gnus-killed-hashtb))
(heads thing-at-point-newsgroup-heads)
htb ret)
(while htbs
(setq htb (car htbs) htbs (cdr htbs))
(ignore-errors
;; errs: htb symbol may be unbound, or not a hash-table.
;; gnus-gethash is just a macro for intern-soft.
(and (symbol-value htb)
(intern-soft string (symbol-value htb))
(setq ret string htbs nil))
;; If we made it this far, gnus is running, so ignore "heads":
(setq heads nil)))
(or ret (not heads)
(let ((head (string-match "\\`\\([[:lower:]]+\\)\\." string)))
(and head (setq head (substring string 0 (match-end 1)))
(member head heads)
(setq ret string))))
ret)))
(put 'url 'end-op (lambda () (end-of-thing 'url)))
(put 'url 'beginning-op (lambda () (end-of-thing '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 &optional distance)
"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))
(forward-bound (and distance (+ (point) distance)))
(backward-bound (and distance (- (point) distance)))
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 forward-bound 'limit)
(while (and (re-search-backward regexp backward-bound 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)))))
;; 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 500)))
(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))))))
;; Buffer
(put 'buffer 'end-op (lambda () (goto-char (point-max))))
(put 'buffer 'beginning-op (lambda () (goto-char (point-min))))
;; Aliases
(defun word-at-point ()
"Return the word at point. See `thing-at-point'."
(thing-at-point 'word))
(defun sentence-at-point ()
"Return the sentence at point. See `thing-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 (ignore-errors
(read-from-whole-string (thing-at-point (or thing 'sexp))))))
(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))
(put 'number 'thing-at-point 'number-at-point)
;;;###autoload
(defun list-at-point ()
"Return the Lisp list at point, or nil if none is found."
(form-at-point 'list 'listp))
;;; thingatpt.el ends here
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