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/files.el	Tue Mar 31 18:42:21 2015 +0100
+++ b/lisp/files.el	Wed Apr 01 14:28:20 2015 +0100
@@ -2487,31 +2487,29 @@
 (defun file-name-sans-extension (filename)
   "Return FILENAME sans final \"extension\".
 The extension, in a file name, is the part that follows the last `.'."
-  (save-match-data
-    (let ((file (file-name-sans-versions (file-name-nondirectory filename)))
-	  directory)
-      (if (string-match "\\.[^.]*\\'" file)
-	  (if (setq directory (file-name-directory filename))
-	      (expand-file-name (substring file 0 (match-beginning 0))
-				directory)
-	    (substring file 0 (match-beginning 0)))
-	filename))))
+  (let* ((file (file-name-sans-versions (file-name-nondirectory filename)))
+         (position (position ?. file :from-end t))
+         (directory (and position (file-name-directory filename))))
+    (if position
+        (if directory
+            (expand-file-name (subseq file 0 position) directory)
+          (subseq file 0 position))
+      filename)))
 
 (defun file-name-extension (filename &optional period)
   "Return FILENAME's final \"extension\".
 The extension, in a file name, is the part that follows the last `.'.
 Return nil for extensionless file names such as `foo'.
-Return the empty string for file names such as `foo'.
+Return the empty string for file names such as `foo.'
 
 If PERIOD is non-nil, then the returned value includes the period
 that delimits the extension, and if FILENAME has no extension,
 the value is \"\"."
-  (save-match-data
-    (let ((file (file-name-sans-versions (file-name-nondirectory filename))))
-      (if (string-match "\\.[^.]*\\'" file)
-          (substring file (+ (match-beginning 0) (if period 0 1)))
-        (if period
-            "")))))
+  (let* ((file (file-name-sans-versions (file-name-nondirectory filename)))
+         (position (position ?. file :from-end t)))
+    (if (and position (not (eql position 0)))
+        (subseq file (+ position (if period 0 1)))
+      (if period ""))))
 
 (defcustom make-backup-file-name-function nil
   "A function to use instead of the default `make-backup-file-name'.
@@ -4247,25 +4245,13 @@
 		;; directory if FILE is a symbolic link.
 		(apply 'call-process
 		       insert-directory-program nil t nil
-		       (let (list)
-			 (if (listp switches)
-			     (setq list switches)
-			   (if (not (equal switches ""))
-			       (let ((switches switches))
-				 ;; Split the switches at any spaces
-				 ;; so we can pass separate options as separate args.
-				 (while (string-match " " switches)
-				   (setq list (cons (substring switches 0 (match-beginning 0))
-						    list)
-					 switches (substring switches (match-end 0))))
-				 (setq list (cons switches list)))))
-			 (append list
-				 (list
-				  (if full-directory-p
-				      (concat (file-name-as-directory file)
-					      ;;#### Unix-specific
-					      ".")
-				    file))))))))
+                       (append (if (listp switches)
+                                   switches
+                                 (split-string-by-char switches ?\ ))
+                               (list
+                                (if full-directory-p
+                                    (concat (file-name-as-directory file) ".")
+                                  file)))))))
 
 	  ;; If we got "//DIRED//" in the output, it means we got a real
 	  ;; directory listing, even if `ls' returned nonzero.
@@ -4294,7 +4280,7 @@
 		     (buffer-string))))
 	      (if (string-match "ls (.*utils) \\([0-9.]*\\)$" version-out)
 		  (let* ((version (match-string 1 version-out))
-			 (split (split-string version "[.]"))
+			 (split (split-string-by-char version ?.))
 			 (numbers (mapcar 'string-to-int split))
 			 (min '(5 2 1))
 			 comparison)