Add isearch-yank-symbol-or-char

* doc/emacs/search.texi (Isearch Yank): Document new
function, keybindings.

* etc/NEWS: Mention isearch changes.

* lisp/isearch.el (isearch--yank-char-or-syntax): New function.
(isearch-yank-word-or-char): Call it.
(isearch-yank-symbol-or-char): New function.
(isearch-mode-map): Change 'C-M-w' binding from
'isearch-del-char' to isearch-yank-symbol-or-char; add 'C-M-d'
binding for 'isearch-del-char'.

3 files changed, 31 insertions, 9 deletions

diff --git a/doc/emacs/search.texi b/doc/emacs/search.texi
index 319f64fbae1..37446ca1c46 100644
--- a/doc/emacs/search.texi
+++ b/doc/emacs/search.texi
@@ -229,6 +229,13 @@ character or word at point to the search string.  This is an easy way
 to search for another occurrence of the text at point.  (The decision
 of whether to copy a character or a word is heuristic.)
 
+@kindex C-M-w @r{(Incremental search)}
+@findex isearch-yank-symbol-or-char
+  @kbd{C-M-w} (@code{isearch-yank-symbol-or-char}) appends the next
+character or symbol at point to the search string.  This is an easy way
+to search for another occurrence of the symbol at point.  (The decision
+of whether to copy a character or a word is heuristic.)
+
 @kindex M-s C-e @r{(Incremental search)}
 @findex isearch-yank-line
   Similarly, @kbd{M-s C-e} (@code{isearch-yank-line}) appends the rest
@@ -250,11 +257,11 @@ appended text with an earlier kill, similar to the usual @kbd{M-y}
 in the echo area appends the current X selection (@pxref{Primary
 Selection}) to the search string (@code{isearch-yank-x-selection}).
 
-@kindex C-M-w @r{(Incremental search)}
+@kindex C-M-d @r{(Incremental search)}
 @kindex C-M-y @r{(Incremental search)}
 @findex isearch-del-char
 @findex isearch-yank-char
-  @kbd{C-M-w} (@code{isearch-del-char}) deletes the last character
+  @kbd{C-M-d} (@code{isearch-del-char}) deletes the last character
 from the search string, and @kbd{C-M-y} (@code{isearch-yank-char})
 appends the character after point to the search string.  An
 alternative method to add the character after point is to enter the
diff --git a/etc/NEWS b/etc/NEWS
index 70bafcd01b4..dacaf023bb1 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -109,6 +109,11 @@ regular expression was previously invalid, but is now accepted:
 
 * Editing Changes in Emacs 27.1
 
++++
+** New isearch bindings.
+'C-M-w' in isearch changed from isearch-del-char to the new function
+isearch-yank-symbol-or-char. isearch-del-char is now bound to 'C-M-d'.
+
 ---
 ** New variable 'x-wait-for-event-timeout'.
 This controls how long Emacs will wait for updates to the graphical
diff --git a/lisp/isearch.el b/lisp/isearch.el
index 1835469bb2c..b6422401a88 100644
--- a/lisp/isearch.el
+++ b/lisp/isearch.el
@@ -480,7 +480,8 @@ This is like `describe-bindings', but displays only Isearch keys."
     (define-key map [?\S-\ ] 'isearch-printing-char)
 
     (define-key map    "\C-w" 'isearch-yank-word-or-char)
-    (define-key map "\M-\C-w" 'isearch-del-char)
+    (define-key map "\M-\C-w" 'isearch-yank-symbol-or-char)
+    (define-key map "\M-\C-d" 'isearch-del-char)
     (define-key map "\M-\C-y" 'isearch-yank-char)
     (define-key map    "\C-y" 'isearch-yank-kill)
     (define-key map "\M-s\C-e" 'isearch-yank-line)
@@ -2089,17 +2090,26 @@ If optional ARG is non-nil, pull in the next ARG characters."
   (interactive "p")
   (isearch-yank-internal (lambda () (forward-char arg) (point))))
 
-(defun isearch-yank-word-or-char ()
-  "Pull next character or word from buffer into search string."
-  (interactive)
+(defun isearch--yank-char-or-syntax (syntax-list fn)
   (isearch-yank-internal
    (lambda ()
-     (if (or (= (char-syntax (or (char-after) 0)) ?w)
-             (= (char-syntax (or (char-after (1+ (point))) 0)) ?w))
-         (forward-word 1)
+     (if (or (memq (char-syntax (or (char-after) 0)) syntax-list)
+             (memq (char-syntax (or (char-after (1+ (point))) 0))
+                   syntax-list))
+         (funcall fn 1)
        (forward-char 1))
      (point))))
 
+(defun isearch-yank-word-or-char ()
+  "Pull next character or word from buffer into search string."
+  (interactive)
+  (isearch--yank-char-or-syntax '(?w) 'forward-word))
+
+(defun isearch-yank-symbol-or-char ()
+  "Pull next character or word from buffer into search string."
+  (interactive)
+  (isearch--yank-char-or-syntax '(?w ?_) 'forward-symbol))
+
 (defun isearch-yank-word (&optional arg)
   "Pull next word from buffer into search string.
 If optional ARG is non-nil, pull in the next ARG words."