* lisp/isearch.el (isearch-word): Add docstring.

(isearch-occur, isearch-search-and-update): If `isearch-word' is
a function, call it to get the regexp.
(isearch-message-prefix): If `isearch-word' holds a symbol, use its
property `isearch-message-prefix' instead of the string "word ".
(isearch-search-fun-default): For the case of `isearch-word',
return a lambda that calls re-search-forward/re-search-backward
with a regexp returned by `word-search-regexp' or by the function
in `isearch-word'.

Fixes: debbugs:11381

2 files changed, 46 insertions, 13 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index c155b0a27c0..ae410d54075 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,17 @@
 2012-05-29  Juri Linkov  <juri@jurta.org>
 
+        * isearch.el (isearch-word): Add docstring.  (Bug#11381)
+        (isearch-occur, isearch-search-and-update): If `isearch-word' is
+        a function, call it to get the regexp.
+        (isearch-message-prefix): If `isearch-word' holds a symbol, use its
+        property `isearch-message-prefix' instead of the string "word ".
+        (isearch-search-fun-default): For the case of `isearch-word',
+        return a lambda that calls re-search-forward/re-search-backward
+        with a regexp returned by `word-search-regexp' or by the function
+        in `isearch-word'.
+
+2012-05-29  Juri Linkov  <juri@jurta.org>
+
         * isearch.el (isearch-search-fun-default): New function.
         (isearch-search-fun): Move default part to the new function
         `isearch-search-fun-default'.
diff --git a/lisp/isearch.el b/lisp/isearch.el
index 2fcd2d53251..8564a390314 100644
--- a/lisp/isearch.el
+++ b/lisp/isearch.el
@@ -530,8 +530,13 @@ This is like `describe-bindings', but displays only Isearch keys."
 
 (defvar isearch-forward nil)    ; Searching in the forward direction.
 (defvar isearch-regexp nil)     ; Searching for a regexp.
-(defvar isearch-word nil)       ; Searching for words.
-(defvar isearch-hidden nil) ; Non-nil if the string exists but is invisible.
+(defvar isearch-word nil
+  "Regexp-based search mode for words.
+If t, do incremental search for a sequence of words, ignoring punctuation.
+If the value is a function, it is called to convert the search string
+to a regexp used by regexp search functions.  The property
+`isearch-message-prefix' put on this function specifies the
+prefix string displyed in the search message.")
 
 (defvar isearch-cmds nil
   "Stack of search status sets.
@@ -592,6 +597,9 @@ Each set is a vector of the form:
 ;; Accumulate here the overlays opened during searching.
 (defvar isearch-opened-overlays nil)
 
+;; Non-nil if the string exists but is invisible.
+(defvar isearch-hidden nil)
+
 ;; The value of input-method-function when isearch is invoked.
 (defvar isearch-input-method-function nil)
 
@@ -747,14 +755,14 @@ as a regexp.  See the command `isearch-forward' for more information."
 ;;  "List of commands for which isearch-mode does not recursive-edit.")
 
 
-(defun isearch-mode (forward &optional regexp op-fun recursive-edit word-p)
+(defun isearch-mode (forward &optional regexp op-fun recursive-edit word)
   "Start Isearch minor mode.
 It is called by the function `isearch-forward' and other related functions."
 
   ;; Initialize global vars.
   (setq isearch-forward forward
         isearch-regexp regexp
-        isearch-word word-p
+        isearch-word word
         isearch-op-fun op-fun
         isearch-last-case-fold-search isearch-case-fold-search
         isearch-case-fold-search case-fold-search
@@ -1534,6 +1542,8 @@ characters in that string."
   (interactive
    (let* ((perform-collect (consp current-prefix-arg))
           (regexp (cond
+                   ((functionp isearch-word)
+                    (funcall isearch-word isearch-string))
                    (isearch-word (word-search-regexp isearch-string))
                    (isearch-regexp isearch-string)
                    (t (regexp-quote isearch-string)))))
@@ -1749,6 +1759,8 @@ Subword is used when `subword-mode' is activated. "
                        (setq case-fold-search
                              (isearch-no-upper-case-p isearch-string isearch-regexp)))
                    (looking-at (cond
+                                ((functionp isearch-word)
+                                 (funcall isearch-word isearch-string t))
                                 (isearch-word (word-search-regexp isearch-string t))
                                 (isearch-regexp isearch-string)
                                 (t (regexp-quote isearch-string)))))
@@ -2329,7 +2341,11 @@ If there is no completion possible, say so and continue searching."
                               (< (point) isearch-opoint)))
                        "over")
                    (if isearch-wrapped "wrapped ")
-                   (if isearch-word "word " "")
+                   (if isearch-word
+                       (or (and (symbolp isearch-word)
+                                (get isearch-word 'isearch-message-prefix))
+                           "word ")
+                     "")
                    (if isearch-regexp "regexp " "")
                    (if multi-isearch-next-buffer-current-function "multi " "")
                    (or isearch-message-prefix-add "")
@@ -2374,14 +2390,19 @@ Can be changed via `isearch-search-fun-function' for special needs."
   "Return default functions to use for the search."
   (cond
    (isearch-word
-    ;; Use lax versions to not fail at the end of the word while
-    ;; the user adds and removes characters in the search string
-    ;; (or when using nonincremental word isearch)
-    (if (or isearch-nonincremental
-            (eq (length isearch-string)
-                (length (isearch-string-state (car isearch-cmds)))))
-        (if isearch-forward 'word-search-forward 'word-search-backward)
-      (if isearch-forward 'word-search-forward-lax 'word-search-backward-lax)))
+    (lambda (string &optional bound noerror count)
+      ;; Use lax versions to not fail at the end of the word while
+      ;; the user adds and removes characters in the search string
+      ;; (or when using nonincremental word isearch)
+      (let ((lax (not (or isearch-nonincremental
+                          (eq (length isearch-string)
+                              (length (isearch-string-state (car isearch-cmds))))))))
+        (funcall
+         (if isearch-forward #'re-search-forward #'re-search-backward)
+         (if (functionp isearch-word)
+             (funcall isearch-word string lax)
+           (word-search-regexp string lax))
+         bound noerror count))))
    (isearch-regexp
     (if isearch-forward 're-search-forward 're-search-backward))
    (t