Subject: bug#14602: closed (Done)

From: [email-masked] (GNU bug Tracking System)
Date: Sun, 23 Mar 2014 06:39:06 +0000

Your bug report

#14602: Yank and delete characters in word and symbol isearch

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
14602: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=14602
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Done
From: Daniel Colascione <[email-masked]>
To: [email-masked]
Date: Sat, 22 Mar 2014 23:37:53 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

Worksforme

Subject: Yank and delete characters in word and symbol isearch
From: Juri Linkov <[email-masked]>
To: [email-masked]
Date: Wed, 12 Jun 2013 23:57:04 +0300
List-Id: <debbugs-submit.debbugs.gnu.org>

As found in http://lists.gnu.org/archive/html/emacs-devel/2013-06/msg00390.html
the currently existing commands `isearch-yank-char' and `isearch-del-char'
fail to yank and delete characters in a word/symbol search.

The test case is typing `M-s w C-M-y C-M-y ... C-M-w C-M-w ...'
in the middle of a word/symbol or at the beginning/end of a word/symbol.

To remove the failure to yank a character in the middle of a word/symbol
it helps to lax the regexp at both ends of the word/symbol.

And to remove the failure to yank a character at the beginning/end
of a word/symbol it helps to match leading/trailing whitespace
at the word/symbol boundaries as well.

Then both `word-search-regexp' and `isearch-symbol-regexp' could share
the same body with the difference where the former uses word-based regexps
with \\<, \\> and \\W, and the latter uses symbol-based regexps with
\\_< and \\_>.

The remaining problem is how to translate \\W to the symbol-based regexp that
will match a non-word non-symbol character.  The only solution that I found is
to list all possible syntaxes except word and symbol syntax.

I tested this and it successfully passes all tests.

=== modified file 'lisp/isearch.el'
--- lisp/isearch.el	2013-06-06 06:23:19 +0000
+++ lisp/isearch.el	2013-06-12 20:48:17 +0000
@@ -1545,12 +1649,15 @@ (defun word-search-regexp (string &optio
 
 Used in `word-search-forward', `word-search-backward',
 `word-search-forward-lax', `word-search-backward-lax'."
-  (if (string-match-p "^\\W*$" string)
-      ""
-    (concat
-     "\\b"
-     (mapconcat 'identity (split-string string "\\W+" t) "\\W+")
-     (if (or (not lax) (string-match-p "\\W$" string)) "\\b"))))
+  (cond
+   ((equal string "") "")
+   ((string-match-p "\\`\\W+\\'" string) "\\W+")
+   (t (concat
+       (if (string-match-p "\\`\\W" string) "\\W+"
+	 (unless lax "\\<"))
+       (mapconcat 'regexp-quote (split-string string "\\W+" t) "\\W+")
+       (if (string-match-p "\\W\\'" string) "\\W+"
+	 (unless lax "\\>"))))))
 
 (defun word-search-backward (string &optional bound noerror count)
   "Search backward from point for STRING, ignoring differences in punctuation.
@@ -1627,7 +1733,17 @@ (defun isearch-symbol-regexp (string &op
   "Return a regexp which matches STRING as a symbol.
 Creates a regexp where STRING is surrounded by symbol delimiters \\_< and \\_>.
 If LAX is non-nil, the end of the string need not match a symbol boundary."
-  (concat "\\_<" (regexp-quote string) (unless lax "\\_>")))
+  (let ((not-word-symbol-re
+	 "\\(?:\\s-\\|\\s.\\|\\s(\\|\\s)\\|\\s\"\\|\\s\\\\|\\s/\\|\\s$\\|\\s'\\|\\s<\\|\\s>\\|\\s@\\|\\s!\\|\\s|\\)+"))
+    (cond
+     ((equal string "") "")
+     ((string-match-p (format "\\`%s\\'" not-word-symbol-re) string) not-word-symbol-re)
+     (t (concat
+	 (if (string-match-p (format "\\`%s" not-word-symbol-re) string) not-word-symbol-re
+	   (unless lax "\\_<"))
+	 (mapconcat 'regexp-quote (split-string string not-word-symbol-re t) not-word-symbol-re)
+	 (if (string-match-p (format "%s\\'" not-word-symbol-re) string) not-word-symbol-re
+	   (unless lax "\\_>")))))))
 
 (put 'isearch-symbol-regexp 'isearch-message-prefix "symbol ")