(thing-at-point): Use `thing-at-point' property, if any.

(bounds-of-thing-at-point): Use `bounds-of-thing-at-point' property.
(thing-at-point-bounds-of-url-at-point): New function.
(thing-at-point-looking-at): New function, adapted from old
browse-url-looking-at.
(thing-at-point-url-at-point): New function, adapted from
browse-url-url-at-point.
(thing-at-point-url-chars): Variable deleted.
(thing-at-point-url-path-regexp, thing-at-point-short-url-regexp,
thing-at-point-url-regexp, thing-at-point-markedup-url-regexp):
New variables.
(url): `beginning-op' property function changed to use
`thing-at-point-bounds-of-url-at-point'.  `end-op' property no
longer set -- functionality no longer supported for the more
sophisticated treatment of URLs so `forward-thing' no longer works
in this case.

1 files changed, 155 insertions, 56 deletions

diff --git a/lisp/thingatpt.el b/lisp/thingatpt.el
index 436f2ff3589..4ea50c5dd23 100644
--- a/lisp/thingatpt.el
+++ b/lisp/thingatpt.el
@@ -1,6 +1,6 @@
 ;;; thingatpt.el --- Get the `thing' at point
 
-;; Copyright (C) 1991,92,93,94,95,1996 Free Software Foundation, Inc.
+;; Copyright (C) 1991,92,93,94,95,96,1997 Free Software Foundation, Inc.
 
 ;; Author: Mike Williams <mikew@gopher.dosli.govt.nz>
 ;; Keywords: extensions, matching, mouse
@@ -72,54 +72,56 @@ 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."
-  (let ((orig (point)))
-    (condition-case nil
-        (save-excursion
-          ;; Try moving forward, then back.
-          (let ((end (progn 
-                       (funcall 
-                        (or (get thing 'end-op) 
-                            (function (lambda () (forward-thing thing 1)))))
-                       (point)))
-                (beg (progn 
-                       (funcall 
-                        (or (get thing 'beginning-op) 
-                            (function (lambda () (forward-thing thing -1)))))
-                       (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 
+  (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.
+            (let ((end (progn 
                          (funcall 
                           (or (get thing 'end-op) 
                               (function (lambda () (forward-thing thing 1)))))
+                         (point)))
+                  (beg (progn 
+                         (funcall 
+                          (or (get thing 'beginning-op) 
+                              (function (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.
-              (let ((beg (progn 
-                           (funcall 
-                            (or (get thing 'beginning-op) 
-                                (function (lambda () (forward-thing thing -1)))))
-                           (point)))
-                    (end (progn 
+              (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) 
                                 (function (lambda () (forward-thing thing 1)))))
-                           (point)))
-                    (real-beg
-                     (progn 
-                       (funcall 
-                        (or (get thing 'beginning-op) 
-                            (function (lambda () (forward-thing thing -1)))))
-                       (point))))
-                (if (and real-beg end (<= real-beg orig) (<= orig end))
-                    (cons real-beg end))))))
-      (error nil))))
+                           (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.
+                (let ((beg (progn 
+                             (funcall 
+                              (or (get thing 'beginning-op) 
+                                  (function (lambda () (forward-thing thing -1)))))
+                             (point)))
+                      (end (progn 
+                             (funcall 
+                              (or (get thing 'end-op) 
+                                  (function (lambda () (forward-thing thing 1)))))
+                             (point)))
+                      (real-beg
+                       (progn 
+                         (funcall 
+                          (or (get thing 'beginning-op) 
+                              (function (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)
@@ -130,9 +132,11 @@ Possibilities include `symbol', `list', `sexp', `defun', `filename', `url',
 
 See the file `thingatpt.el' for documentation on how to define
 a symbol as a valid THING."
-  (let ((bounds (bounds-of-thing-at-point thing)))
-    (if bounds 
-        (buffer-substring (car bounds) (cdr bounds)))))
+  (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
 
@@ -197,19 +201,114 @@ a symbol as a valid THING."
 (put 'filename 'beginning-op
      '(lambda () (skip-chars-backward thing-at-point-file-name-chars)))
 
-(defvar thing-at-point-url-chars "~/A-Za-z0-9---_@$%&=.,"
-  "Characters allowable in a URL.")
-
-(put 'url 'end-op    
-     '(lambda () (skip-chars-forward (concat ":" thing-at-point-url-chars))
-        (skip-chars-backward ".,:")))
+(defvar thing-at-point-url-path-regexp
+  "[^]\t\n \"'()<>[^`{}]*[^]\t\n \"'()<>[^`{}.,;]+"
+  "A regular expression probably matching the host, path 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-url-regexp
+  (concat
+   "\\(https?://\\|ftp://\\|gopher://\\|telnet://\\|wais://\\|file:/\\|s?news:\\|mailto:\\)"
+   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 ((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)))
+        (let ((beginning (match-beginning 0))
+              (end (match-end 0)))
+          (cond (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, `http://'
+will be prepended if absent."
+  (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 "\\s +\\|\n+" url)
+            (setq url (replace-match "" t t url)))
+          (and short (setq url (concat (if (string-match "@" url)
+                                           "mailto:" "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)))))
+
+;; Can't do it sensibly?
+;(put 'url 'end-op    
+;     '(lambda () (skip-chars-forward (concat ":" thing-at-point-url-chars))
+;       (skip-chars-backward ".,:")))
 (put 'url 'beginning-op
      '(lambda ()
-        (skip-chars-backward thing-at-point-url-chars)
-        (or (= (preceding-char) ?:)
-            (error "No URL here"))
-        (forward-char -1)
-        (skip-chars-backward "a-zA-Z")))
+        (let ((bounds (thing-at-point-bounds-of-url-at-point)))
+          (if bounds
+              (goto-char (car bounds))
+            (error "No URL here")))))
 
 ;;  Whitespace