Re: isearch-forward and Info-search

[Juri Linkov]

Stefan Monnier <address@hidden> writes:
> The implementation looks clean.  I just suggest that we should simply
> replace isearch-invalid-regexp with isearch-error (there can only be one
> error at any given time, either a search failure or an invalid regexp, or
> ...).

OK.

I also removed `isearch-within-brackets' because it is used nowhere
within Emacs.  And added `condition-case' around the call to
`isearch-search-fun' in `isearch-lazy-highlight-search' to return nil
in case of error which allows `isearch-lazy-highlight-update' to try to
highlight matches from the window beginning (needed for Info isearch).

Index: lisp/isearch.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/isearch.el,v
retrieving revision 1.256
diff -u -r1.256 isearch.el
--- lisp/isearch.el     19 Feb 2005 20:52:47 -0000      1.256
+++ lisp/isearch.el     13 Mar 2005 00:55:45 -0000
@@ -437,9 +437,8 @@
 (defvar isearch-string "")  ; The current search string.
 (defvar isearch-message "") ; text-char-description version of isearch-string
 
-(defvar isearch-success t)             ; Searching is currently successful.
-(defvar isearch-invalid-regexp nil)    ; Regexp not well formed.
-(defvar isearch-within-brackets nil)   ; Regexp has unclosed [.
+(defvar isearch-success t)     ; Searching is currently successful.
+(defvar isearch-error nil)     ; Error message for failed search.
 (defvar isearch-other-end nil) ; Start (end) of match if forward (backward).
 (defvar isearch-wrapped nil)   ; Searching restarted from the top (bottom).
 (defvar isearch-barrier 0)
@@ -640,8 +639,7 @@
        isearch-barrier (point)
        isearch-adjusted nil
        isearch-yank-flag nil
-       isearch-invalid-regexp nil
-       isearch-within-brackets nil
+       isearch-error nil
        isearch-slow-terminal-mode (and (<= baud-rate search-slow-speed)
                                        (> (window-height)
                                           (* 4
@@ -867,7 +865,7 @@
 (defsubst isearch-word-state (frame)
   "Return the search-by-word flag in FRAME."
   (aref frame 6))
-(defsubst isearch-invalid-regexp-state (frame)
+(defsubst isearch-error-state (frame)
   "Return the regexp error message in FRAME, or nil if its regexp is valid."
   (aref frame 7))
 (defsubst isearch-wrapped-state (frame)
@@ -876,15 +874,12 @@
 (defsubst isearch-barrier-state (frame)
   "Return the barrier value in FRAME."
   (aref frame 9))
-(defsubst isearch-within-brackets-state (frame)
-  "Return the in-character-class flag in FRAME."
-  (aref frame 10))
 (defsubst isearch-case-fold-search-state (frame)
   "Return the case-folding flag in FRAME."
-  (aref frame 11))
+  (aref frame 10))
 (defsubst isearch-pop-fun-state (frame)
   "Return the function restoring the mode-specific isearch state in FRAME."
-  (aref frame 12))
+  (aref frame 11))
 
 (defun isearch-top-state ()
   (let ((cmd (car isearch-cmds)))
@@ -894,10 +889,9 @@
          isearch-forward (isearch-forward-state cmd)
          isearch-other-end (isearch-other-end-state cmd)
          isearch-word (isearch-word-state cmd)
-         isearch-invalid-regexp (isearch-invalid-regexp-state cmd)
+         isearch-error (isearch-error-state cmd)
          isearch-wrapped (isearch-wrapped-state cmd)
          isearch-barrier (isearch-barrier-state cmd)
-         isearch-within-brackets (isearch-within-brackets-state cmd)
          isearch-case-fold-search (isearch-case-fold-search-state cmd))
     (if (functionp (isearch-pop-fun-state cmd))
        (funcall (isearch-pop-fun-state cmd) cmd))
@@ -912,8 +906,8 @@
        (cons (vector isearch-string isearch-message (point)
                      isearch-success isearch-forward isearch-other-end
                      isearch-word
-                     isearch-invalid-regexp isearch-wrapped isearch-barrier
-                     isearch-within-brackets isearch-case-fold-search
+                     isearch-error isearch-wrapped isearch-barrier
+                     isearch-case-fold-search
                      (if isearch-push-state-function
                          (funcall isearch-push-state-function)))
              isearch-cmds)))
@@ -976,8 +970,7 @@
              (isearch-barrier isearch-barrier)
              (isearch-adjusted isearch-adjusted)
              (isearch-yank-flag isearch-yank-flag)
-             (isearch-invalid-regexp isearch-invalid-regexp)
-             (isearch-within-brackets isearch-within-brackets)
+             (isearch-error isearch-error)
   ;;; Don't bind this.  We want isearch-search, below, to set it.
   ;;; And the old value won't matter after that.
   ;;;      (isearch-other-end isearch-other-end)
@@ -1124,7 +1117,7 @@
         (isearch-cancel))
     ;; If search is failing, or has an incomplete regexp,
     ;; rub out until it is once more successful.
-    (while (or (not isearch-success) isearch-invalid-regexp)
+    (while (or (not isearch-success) isearch-error)
       (isearch-pop-state))
     (isearch-update)))
 
@@ -1146,10 +1139,11 @@
        ;; If already have what to search for, repeat it.
        (or isearch-success
            (progn
+             ;; Set isearch-wrapped before calling isearch-wrap-function
+             (setq isearch-wrapped t)
              (if isearch-wrap-function
                  (funcall isearch-wrap-function)
-               (goto-char (if isearch-forward (point-min) (point-max))))
-             (setq isearch-wrapped t))))
+               (goto-char (if isearch-forward (point-min) (point-max)))))))
     ;; C-s in reverse or C-r in forward, change direction.
     (setq isearch-forward (not isearch-forward)))
 
@@ -1384,8 +1378,7 @@
                     (min isearch-opoint isearch-barrier))))
        (progn
          (setq isearch-success t
-               isearch-invalid-regexp nil
-               isearch-within-brackets nil
+               isearch-error nil
                isearch-other-end (match-end 0))
          (if (and (eq isearch-case-fold-search t) search-upper-case)
              (setq isearch-case-fold-search
@@ -1432,8 +1425,8 @@
                                (not want-backslash))
             ;; We have to check 2 stack frames because the last might be
             ;; invalid just because of a backslash.
-            (or (not isearch-invalid-regexp)
-                (not (isearch-invalid-regexp-state (cadr isearch-cmds)))
+            (or (not isearch-error)
+                (not (isearch-error-state (cadr isearch-cmds)))
                 allow-invalid))
     (if to-barrier
        (progn (goto-char isearch-barrier)
@@ -1448,7 +1441,7 @@
        ;; Also skip over postfix operators -- though horrid,
        ;; 'ab?\{5,6\}+\{1,2\}*' is perfectly legal.
        (while (and previous
-                   (or (isearch-invalid-regexp-state frame)
+                   (or (isearch-error-state frame)
                        (let* ((string (isearch-string-state frame))
                               (lchar (aref string (1- (length string)))))
                          ;; The operators aren't always operators; check
@@ -1981,11 +1974,10 @@
   ;; If about to search, and previous search regexp was invalid,
   ;; check that it still is.  If it is valid now,
   ;; let the message we display while searching say that it is valid.
-  (and isearch-invalid-regexp ellipsis
+  (and isearch-error ellipsis
        (condition-case ()
           (progn (re-search-forward isearch-string (point) t)
-                 (setq isearch-invalid-regexp nil
-                       isearch-within-brackets nil))
+                 (setq isearch-error nil))
         (error nil)))
   ;; If currently failing, display no ellipsis.
   (or isearch-success (setq ellipsis nil))
@@ -2011,8 +2003,8 @@
 
 (defun isearch-message-suffix (&optional c-q-hack ellipsis)
   (concat (if c-q-hack "^Q" "")
-         (if isearch-invalid-regexp
-             (concat " [" isearch-invalid-regexp "]")
+         (if isearch-error
+             (concat " [" isearch-error "]")
            "")))
 
 
@@ -2049,8 +2041,7 @@
            (case-fold-search isearch-case-fold-search)
            (search-spaces-regexp search-whitespace-regexp)
            (retry t))
-       (if isearch-regexp (setq isearch-invalid-regexp nil))
-       (setq isearch-within-brackets nil)
+       (setq isearch-error nil)
        (while retry
          (setq isearch-success
                (funcall
@@ -2074,16 +2065,19 @@
          (setq isearch-success nil))
 
     (invalid-regexp
-     (setq isearch-invalid-regexp (car (cdr lossage)))
-     (setq isearch-within-brackets (string-match "\\`Unmatched \\["
-                                                isearch-invalid-regexp))
+     (setq isearch-error (car (cdr lossage)))
      (if (string-match
          "\\`Premature \\|\\`Unmatched \\|\\`Invalid "
-         isearch-invalid-regexp)
-        (setq isearch-invalid-regexp "incomplete input")))
+         isearch-error)
+        (setq isearch-error "incomplete input")))
+
+    (search-failed
+     (setq isearch-success nil)
+     (setq isearch-error (nth 2 lossage)))
+
     (error
      ;; stack overflow in regexp search.
-     (setq isearch-invalid-regexp (format "%s" lossage))))
+     (setq isearch-error (format "%s" lossage))))
 
   (if isearch-success
       nil
@@ -2315,7 +2309,7 @@
 ;;    `isearch-word' and `isearch-regexp';
 ;;  - the direction of the current search is expected to be given by
 ;;    `isearch-forward';
-;;  - the variable `isearch-invalid-regexp' is expected to be true
+;;  - the variable `isearch-error' is expected to be true
 ;;    iff `isearch-string' is an invalid regexp.
 
 (defvar isearch-lazy-highlight-overlays nil)
@@ -2369,7 +2363,7 @@
                          isearch-lazy-highlight-window-end))))
     ;; something important did indeed change
     (isearch-lazy-highlight-cleanup t) ;kill old loop & remove overlays
-    (when (not isearch-invalid-regexp)
+    (when (not isearch-error)
       (setq isearch-lazy-highlight-start-limit beg
            isearch-lazy-highlight-end-limit end)
       (setq isearch-lazy-highlight-window       (selected-window)
@@ -2391,18 +2385,20 @@
 Attempt to do the search exactly the way the pending isearch would."
   (let ((case-fold-search isearch-case-fold-search)
        (search-spaces-regexp search-whitespace-regexp))
-    (funcall (isearch-search-fun)
-             isearch-string
-             (if isearch-forward
-                 (min (or isearch-lazy-highlight-end-limit (point-max))
-                     (if isearch-lazy-highlight-wrapped
-                         isearch-lazy-highlight-start
-                       (window-end)))
-               (max (or isearch-lazy-highlight-start-limit (point-min))
-                   (if isearch-lazy-highlight-wrapped
-                       isearch-lazy-highlight-end
-                     (window-start))))
-             t)))
+    (condition-case nil
+       (funcall (isearch-search-fun)
+                isearch-string
+                (if isearch-forward
+                    (min (or isearch-lazy-highlight-end-limit (point-max))
+                         (if isearch-lazy-highlight-wrapped
+                             isearch-lazy-highlight-start
+                           (window-end)))
+                  (max (or isearch-lazy-highlight-start-limit (point-min))
+                       (if isearch-lazy-highlight-wrapped
+                           isearch-lazy-highlight-end
+                         (window-start))))
+                t)
+      (error nil))))
 
 (defun isearch-lazy-highlight-update ()
   "Update highlighting of other matches for current search."

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