Reduce regexp usage, now CL-oriented non-regexp code available, core Lisp lisp/ChangeLog addition: 2015-04-01 Aidan Kehoe <kehoea@parhasard.net> When calling #'string-match with a REGEXP without regular expression special characters, call #'search, #'mismatch, #'find, etc. instead, making our code less likely to side-effect other functions' match data and a little faster. * apropos.el (apropos-command): * apropos.el (apropos): Call (position ?\n ...) rather than (string-match "\n" ...) here. * buff-menu.el: * buff-menu.el (buffers-menu-omit-invisible-buffers): Don't fire up the regexp engine just to check if a string starts with a space. * buff-menu.el (select-buffers-tab-buffers-by-mode): Don't fire up the regexp engine just to compare mode basenames. * buff-menu.el (format-buffers-tab-line): * buff-menu.el (build-buffers-tab-internal): Moved to being a label within the following. * buff-menu.el (buffers-tab-items): Use the label. * bytecomp.el (byte-compile-log-1): Don't fire up the regexp engine just to look for a newline. * cus-edit.el (get): Ditto. * cus-edit.el (custom-variable-value-create): Ditto, but for a colon. * descr-text.el (describe-text-sexp): Ditto. * descr-text.el (describe-char-unicode-data): Use #'split-string-by-char given that we're just looking for a semicolon. * descr-text.el (describe-char): Don't fire up the regexp engine just to look for a newline. * disass.el (disassemble-internal): Ditto. * files.el (file-name-sans-extension): Implement this using #'position. * files.el (file-name-extension): Correct this function's docstring, implement it in terms of #'position. * files.el (insert-directory): Don't fire up the regexp engine to split a string by space; don't reverse the list of switches, this is actually a longstand bug as far as I can see. * gnuserv.el (gnuserv-process-filter): Use #'position here, instead of consing inside #'split-string needlessly. * gtk-file-dialog.el (gtk-file-dialog-update-dropdown): Use #'split-string-by-char here, don't fire up #'split-string for directory-sep-char. * gtk-font-menu.el (hack-font-truename): Implement this more cheaply in terms of #'find, #'split-string-by-char, #'equal, rather than #'string-match, #'split-string, #'string-equal. * hyper-apropos.el (hyper-apropos-grok-functions): * hyper-apropos.el (hyper-apropos-grok-variables): Look for a newline using #'position rather than #'string-match in these functions. * info.el (Info-insert-dir): * info.el (Info-insert-file-contents): * info.el (Info-follow-reference): * info.el (Info-extract-menu-node-name): * info.el (Info-menu): Look for fixed strings using #'position or #'search as appropriate in this file. * ldap.el (ldap-decode-string): * ldap.el (ldap-encode-string): #'encode-coding-string, #'decode-coding-string are always available, don't check if they're fboundp. * ldap.el (ldap-decode-address): * ldap.el (ldap-encode-address): Use #'split-string-by-char in these functions. * lisp-mnt.el (lm-creation-date): * lisp-mnt.el (lm-last-modified-date): Don't fire up the regexp engine just to look for spaces in this file. * menubar-items.el (default-menubar): Use (not (mismatch ...)) rather than #'string-match here, for simple regexp. Use (search "beta" ...) rather than (string-match "beta" ...) * menubar-items.el (sort-buffers-menu-alphabetically): * menubar-items.el (sort-buffers-menu-by-mode-then-alphabetically): * menubar-items.el (group-buffers-menu-by-mode-then-alphabetically): Don't fire up the regexp engine to check if a string starts with a space or an asterisk. Use the more fine-grained results of #'compare-strings; compare case-insensitively for the buffer menu. * menubar-items.el (list-all-buffers): * menubar-items.el (tutorials-menu-filter): Use #'equal rather than #'string-equal, which, in this context, has the drawback of not having a bytecode, and no redeeming features. * minibuf.el: * minibuf.el (un-substitute-in-file-name): Use #'count, rather than counting the occurences of $ using the regexp engine. * minibuf.el (read-file-name-internal-1): Don't fire up the regexp engine to search for ?=. * mouse.el (mouse-eval-sexp): Check for newline with #'find. * msw-font-menu.el (mswindows-reset-device-font-menus): Split a string by newline with #'split-string-by-char. * mule/japanese.el: * mule/japanese.el ("Japanese"): Use #'search rather than #'string-match; canoncase before comparing; fix a bug I had introduced where I had been making case insensitive comparisons where the case mattered. * mule/korea-util.el (default-korean-keyboard): Look for ?3 using #'find, not #'string-march. * mule/korea-util.el (quail-hangul-switch-hanja): Search for a fixed string using #'search. * mule/mule-cmds.el (set-locale-for-language-environment): #'position, #'substitute rather than #'string-match, #'replace-in-string. * newcomment.el (comment-make-extra-lines): Use #'search rather than #'string-match for a simple string. * package-get.el (package-get-remote-filename): Use #'position when looking for ?@ * process.el (setenv): * process.el (read-envvar-name): Use #'position when looking for ?=. * replace.el (map-query-replace-regexp): Use #'split-string-by-char instead of using an inline implementation of it. * select.el (select-convert-from-cf-text): * select.el (select-convert-from-cf-unicodetext): Use #'position rather than #'string-match in these functions. * setup-paths.el (paths-emacs-data-root-p): Use #'search when looking for simple string. * sound.el (load-sound-file): Use #'split-string-by-char rather than an inline reimplementation of same. * startup.el (splash-screen-window-body): * startup.el (splash-screen-tty-body): Search for simple strings using #'search. * version.el (emacs-version): Ditto. * x-font-menu.el (hack-font-truename): Implement this more cheaply in terms of #'find, #'split-string-by-char, #'equal, rather than #'string-match, #'split-string, #'string-equal. * x-font-menu.el (x-reset-device-font-menus-core): Use #'split-string-by-char here. * x-init.el (x-initialize-keyboard): Search for a simple string using #'search.

--- a/lisp/buff-menu.el	Tue Mar 31 18:42:21 2015 +0100
+++ b/lisp/buff-menu.el	Wed Apr 01 14:28:20 2015 +0100
@@ -649,10 +649,10 @@
 			     files-only))
     buffer))
 
-(defun buffers-menu-omit-invisible-buffers (buf)
+(defun buffers-menu-omit-invisible-buffers (buffer)
   "For use as a value of `buffers-menu-omit-function'.
 Omits normally invisible buffers (those whose name begins with a space)."
-  (not (null (string-match "\\` " (buffer-name buf)))))
+  (eql ?\  (elt (buffer-name buffer) 0)))
 
 ;;; The Buffers tab
 
@@ -788,14 +788,14 @@
 	(mode2 (symbol-name (symbol-value-in-buffer 'major-mode 
 						    buffer-to-select)))
 	(modenm1 (symbol-value-in-buffer 'mode-name buf1))
-	(modenm2 (symbol-value-in-buffer 'mode-name buffer-to-select)))
+	(modenm2 (symbol-value-in-buffer 'mode-name buffer-to-select))
+        position mismatch)
     (cond ((or (eq mode1 mode2)
 	       (eq modenm1 modenm2)
-	       (and (string-match "^[^-]+-" mode1)
-		    (string-match
-		     (concat "^" (regexp-quote 
-				  (substring mode1 0 (match-end 0))))
-		     mode2))
+	       (and (setq position (position ?- mode1)) (> position 0)
+                    (prog2
+                        (setq mismatch (mismatch mode1 mode2 :end1 position))
+                        (not (or (null mismatch) (eql mismatch position)))))
 	       (and buffers-tab-grouping-regexp
 		    (find-if #'(lambda (x)
 				 (or
@@ -810,30 +810,16 @@
 (defun format-buffers-tab-line (buffer)
   "For use as a value of `buffers-tab-format-buffer-line-function'.
 This just returns the buffer's name, optionally truncated."
-  (let ((len (specifier-instance buffers-tab-default-buffer-line-length)))
-    (if (and (> len 0)
-	     (> (length (buffer-name buffer)) len))
-	(if (string-match ".*<.>$" (buffer-name buffer))
-	    (concat (substring (buffer-name buffer) 
-			       0 (- len 6)) "..."
-			       (substring (buffer-name buffer) -3))
-	  (concat (substring (buffer-name buffer)
-			     0 (- len 3)) "..."))
-      (buffer-name buffer))))
-
-(defsubst build-buffers-tab-internal (buffers)
-  (let ((selected t))
-    (mapcar
-     #'(lambda (buffer)
-	 (prog1
-	     (vector 
-	      (funcall buffers-tab-format-buffer-line-function
-		       buffer)
-	      (list buffers-tab-switch-to-buffer-function
-		    (buffer-name buffer))
-	      :selected selected)
-	   (when selected (setq selected nil))))
-     buffers)))
+  (let* ((len (specifier-instance buffers-tab-default-buffer-line-length))
+         (buffer-name (buffer-name buffer))
+         (len1 (length buffer-name)))
+    (if (and (> len 0) (> len1 len))
+	(if (and (> len1 3) (eql ?< (aref buffer-name (- len1 3)))
+                 (eql ?> (aref buffer-name (1- len1))))
+	    (concat (subseq buffer-name 0 (- len 6))
+                    "..." (subseq buffer-name -3))
+          (concat (subseq buffer-name 0 (- len 3)) "..."))
+      buffer-name)))
 
 ;;; #### SJT would like this function to have a sort function list. I
 ;;; don't see how this could work given that sorting is not
@@ -868,16 +854,14 @@
       ;; filter buffers
       (when buffers-tab-filter-functions
 	(setq buffers
-	      (delete-if 
-	       #'null 
-	       (mapcar #'(lambda (buf)
-			   (let ((tmp-buf buf))
-			     (mapc #'(lambda (fun)
-				       (unless (funcall fun buf first-buf)
-					 (setq tmp-buf nil)))
-				   buffers-tab-filter-functions)
-			     tmp-buf))
-		       buffers))))
+              (mapcan #'(lambda (buf)
+                          (let ((tmp-buf buf))
+                            (mapc #'(lambda (fun)
+                                      (unless (funcall fun buf first-buf)
+                                        (setq tmp-buf nil)))
+                                  buffers-tab-filter-functions)
+                            (and tmp-buf (list tmp-buf))))
+                      buffers)))
       ;; maybe shorten list of buffers
       (and (integerp buffers-tab-max-size)
 	   (> buffers-tab-max-size 1)
@@ -886,9 +870,23 @@
       ;; sort buffers in group (default is most-recently-selected)
       (when buffers-tab-sort-function
 	(setq buffers (funcall buffers-tab-sort-function buffers)))
-      ;; convert list of buffers to list of structures used by tab widget
-      (setq buffers (build-buffers-tab-internal buffers))
-      buffers)))
+      (labels
+          ((build-buffers-tab-internal (buffers)
+             (let ((selected t))
+               (mapcar
+                #'(lambda (buffer)
+                    (prog1
+                        (vector 
+                         (funcall buffers-tab-format-buffer-line-function
+                                  buffer)
+                         (list buffers-tab-switch-to-buffer-function
+                               (buffer-name buffer))
+                         :selected selected)
+                      (when selected (setq selected nil))))
+                buffers))))
+        ;; convert list of buffers to list of structures used by tab widget
+        (setq buffers (build-buffers-tab-internal buffers))
+        buffers))))
 
 (provide 'buff-menu)