Re: word search (Re: isearch in Dired)

[Juri Linkov <juri@jurta.org>]

>> As for 3-state regexp/word toggles, I currently have no idea for a
>> good key: "r" means "regexp" and "w" means "word", but I don't see
>> what a key would be common for them.
>
> r - regular expression search
> w - word search
> s - search

When you want to switch to the regexp search then the most natural key
is "r".  When you want to switch to the word search then the most natural
key is "w".  Currently I see no alternative common key whose mnemonics
would be obvious.  So to toggle to the regexp or word search and back
to the non-regexp non-word search could be done using either of two keys
`M-s r' or `M-s w'.  It seems there is no problem with this.  In this
case, the following patch looks like a satisfactory solution.  It also
binds `M-s w' globally to start word isearch.

Index: lisp/isearch.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/isearch.el,v
retrieving revision 1.324
diff -c -r1.324 isearch.el
*** lisp/isearch.el	27 Jul 2008 18:24:30 -0000	1.324
--- lisp/isearch.el	29 Jul 2008 15:43:27 -0000
***************
*** 491,496 ****
--- 491,499 ----
      (define-key map "\M-r" 'isearch-toggle-regexp)
      (define-key map "\M-e" 'isearch-edit-string)
  
+     (define-key map "\M-sr" 'isearch-toggle-regexp)
+     (define-key map "\M-sw" 'isearch-toggle-word)
+ 
      (define-key map [?\M-%] 'isearch-query-replace)
      (define-key map [?\C-\M-%] 'isearch-query-replace-regexp)
      (define-key map "\M-so" 'isearch-occur)
***************
*** 596,601 ****
--- 599,605 ----
  (define-key esc-map "\C-s" 'isearch-forward-regexp)
  (define-key global-map "\C-r" 'isearch-backward)
  (define-key esc-map "\C-r" 'isearch-backward-regexp)
+ (define-key search-map "w" 'isearch-forward-word)
  
  ;; Entry points to isearch-mode.
  
***************
*** 684,689 ****
--- 693,708 ----
    (interactive "P\np")
    (isearch-mode t (null not-regexp) nil (not no-recursive-edit)))
  
+ (defun isearch-forward-word (&optional not-word no-recursive-edit)
+   "\
+ Do incremental search forward for a sequence of words.
+ With a prefix argument, do a regular string search instead.
+ Like ordinary incremental search except that your input
+ is treated as a sequence of words without regard to how the
+ words are separated.  See \\[isearch-forward] for more info."
+   (interactive "P\np")
+   (isearch-mode t nil nil (not no-recursive-edit) (null not-word)))
+ 
  (defun isearch-backward (&optional regexp-p no-recursive-edit)
    "\
  Do incremental search backward.
***************
*** 1303,1308 ****
--- 1322,1334 ----
    (setq isearch-success t isearch-adjusted t)
    (isearch-update))
  
+ (defun isearch-toggle-word ()
+   "Toggle word searching on or off."
+   (interactive)
+   (setq isearch-word (not isearch-word))
+   (setq isearch-success t isearch-adjusted t)
+   (isearch-update))
+ 
  (defun isearch-toggle-case-fold ()
    "Toggle case folding in searching on or off."
    (interactive)

-- 
Juri Linkov
http://www.jurta.org/emacs/