Examining the result of #'length: `eql', not `=', it's better style & cheaper 2011-03-08 Aidan Kehoe <kehoea@parhasard.net> * buff-menu.el (list-buffers-noselect): * byte-optimize.el (byte-optimize-identity): * byte-optimize.el (byte-optimize-if): * byte-optimize.el (byte-optimize-nth): * byte-optimize.el (byte-optimize-nthcdr): * bytecomp.el (byte-compile-warn-wrong-args): * bytecomp.el (byte-compile-two-args-19->20): * bytecomp.el (byte-compile-list): * bytecomp.el (byte-compile-beginning-of-line): * bytecomp.el (byte-compile-set): * bytecomp.el (byte-compile-set-default): * bytecomp.el (byte-compile-values): * bytecomp.el (byte-compile-values-list): * bytecomp.el (byte-compile-integerp): * bytecomp.el (byte-compile-multiple-value-list-internal): * bytecomp.el (byte-compile-throw): * cl-macs.el (cl-do-arglist): * cl-macs.el (cl-parse-loop-clause): * cl-macs.el (multiple-value-bind): * cl-macs.el (multiple-value-setq): * cl-macs.el (get-setf-method): * cmdloop.el (command-error): * cmdloop.el (y-or-n-p-minibuf): * cmdloop.el (yes-or-no-p-minibuf): * coding.el (unencodable-char-position): * cus-edit.el (custom-face-prompt): * cus-edit.el (custom-buffer-create-internal): * cus-edit.el (widget-face-action): * cus-edit.el (custom-group-value-create): * descr-text.el (describe-char-unicode-data): * dialog-gtk.el (popup-builtin-question-dialog): * dragdrop.el (experimental-dragdrop-drop-log-function): * dragdrop.el (experimental-dragdrop-drop-mime-default): * easymenu.el (easy-menu-add): * easymenu.el (easy-menu-remove): * faces.el (read-face-name): * faces.el (set-face-stipple): * files.el (file-name-non-special): * font.el (font-combine-fonts): * font.el (font-set-face-font): * font.el (font-parse-rgb-components): * font.el (font-rgb-color-p): * font.el (font-color-rgb-components): * gnuserv.el (gnuserv-edit-files): * help.el (key-or-menu-binding): * help.el (function-documentation-1): * help.el (function-documentation): * info.el (info): * isearch-mode.el (isearch-exit): * isearch-mode.el (isearch-edit-string): * isearch-mode.el (isearch-*-char): * isearch-mode.el (isearch-complete1): * ldap.el (ldap-encode-country-string): * ldap.el (ldap-decode-string): * minibuf.el (read-file-name-internal-1): * minibuf.el (read-non-nil-coding-system): * minibuf.el (get-user-response): * mouse.el (drag-window-divider): * mule/ccl.el: * mule/ccl.el (ccl-compile-if): * mule/ccl.el (ccl-compile-break): * mule/ccl.el (ccl-compile-repeat): * mule/ccl.el (ccl-compile-write-repeat): * mule/ccl.el (ccl-compile-call): * mule/ccl.el (ccl-compile-end): * mule/ccl.el (ccl-compile-read-multibyte-character): * mule/ccl.el (ccl-compile-write-multibyte-character): * mule/ccl.el (ccl-compile-translate-character): * mule/ccl.el (ccl-compile-mule-to-unicode): * mule/ccl.el (ccl-compile-unicode-to-mule): * mule/ccl.el (ccl-compile-lookup-integer): * mule/ccl.el (ccl-compile-lookup-character): * mule/ccl.el (ccl-compile-map-multiple): * mule/ccl.el (ccl-compile-map-single): * mule/devan-util.el (devanagari-compose-to-one-glyph): * mule/devan-util.el (devanagari-composition-component): * mule/mule-cmds.el (finish-set-language-environment): * mule/viet-util.el: * mule/viet-util.el (viet-encode-viscii-char): * multicast.el (open-multicast-group): * newcomment.el (comment-quote-nested): * newcomment.el (comment-region): * newcomment.el (comment-dwim): * regexp-opt.el (regexp-opt-group): * replace.el (map-query-replace-regexp): * specifier.el (derive-device-type-from-tag-set): * subr.el (skip-chars-quote): * test-harness.el (test-harness-from-buffer): * test-harness.el (batch-test-emacs): * wid-edit.el (widget-choice-action): * wid-edit.el (widget-symbol-prompt-internal): * wid-edit.el (widget-color-action): * window-xemacs.el (push-window-configuration): * window-xemacs.el (pop-window-configuration): * window.el (quit-window): * x-compose.el (electric-diacritic): It's better style, and cheaper (often one assembler instruction vs. a C funcall in the byte code), to use `eql' instead of `=' when it's clear what numerical type a given result will be. Change much of our code to do this, with the help of a byte-compiler change (not comitted) that looked for calls to #'length (which always returns an integer) in its args.

--- a/lisp/font.el	Tue Mar 08 22:32:49 2011 +0000
+++ b/lisp/font.el	Tue Mar 08 23:41:52 2011 +0000
@@ -428,7 +428,7 @@
   (cond
    ((null args)
     (error "Wrong number of arguments to font-combine-fonts"))
-   ((= (length args) 1)
+   ((eql (length args) 1)
     (car args))
    (t
     (let ((retval (font-combine-fonts-internal (nth 0 args) (nth 1 args))))
@@ -990,7 +990,7 @@
 ;;; ###autoload
 (defun font-set-face-font (&optional face font &rest args)
   (cond
-   ((and (vectorp font) (= (length font) 12))
+   ((and (vectorp font) (eql (length font) 12))
     (let ((font-name (font-create-name font)))
       (set-face-property face 'font-specification font)
       (cond
@@ -1177,28 +1177,28 @@
 	r g b str)
   (cond ((string-match "^#[0-9a-f]+$" color)
 	 (cond
-	  ((= (length color) 4)
+	  ((eql (length color) 4)
 	   (setq r (font-hex-string-to-number (substring color 1 2))
 		 g (font-hex-string-to-number (substring color 2 3))
 		 b (font-hex-string-to-number (substring color 3 4))
 		 r (* r 4096)
 		 g (* g 4096)
 		 b (* b 4096)))
-	  ((= (length color) 7)
+	  ((eql (length color) 7)
 	   (setq r (font-hex-string-to-number (substring color 1 3))
 		 g (font-hex-string-to-number (substring color 3 5))
 		 b (font-hex-string-to-number (substring color 5 7))
 		 r (* r 256)
 		 g (* g 256)
 		 b (* b 256)))
-	  ((= (length color) 10)
+	  ((eql (length color) 10)
 	   (setq r (font-hex-string-to-number (substring color 1 4))
 		 g (font-hex-string-to-number (substring color 4 7))
 		 b (font-hex-string-to-number (substring color 7 10))
 		 r (* r 16)
 		 g (* g 16)
 		 b (* b 16)))
-	  ((= (length color) 13)
+	  ((eql (length color) 13)
 	   (setq r (font-hex-string-to-number (substring color 1 5))
 		 g (font-hex-string-to-number (substring color 5 9))
 		 b (font-hex-string-to-number (substring color 9 13))))
@@ -1233,7 +1233,7 @@
 
 (defun font-rgb-color-p (obj)
   (or (and (vectorp obj)
-	   (= (length obj) 4)
+	   (eql (length obj) 4)
 	   (eq (aref obj 0) 'rgb))))
 
 (defun font-rgb-color-red (obj) (aref obj 1))
@@ -1257,11 +1257,11 @@
       (list (font-rgb-color-red color)
 	    (font-rgb-color-green color)
 	    (font-rgb-color-blue color)))
-     ((and (vectorp color) (= 3 (length color)))
+     ((and (vectorp color) (eql 3 (length color)))
       (list (aref color 0) (aref color 1) (aref color 2)))
-     ((and (listp color) (= 3 (length color)) (floatp (car color)))
+     ((and (listp color) (eql 3 (length color)) (floatp (car color)))
       (mapcar #'(lambda (x) (* x 65535)) color))
-     ((and (listp color) (= 3 (length color)))
+     ((and (listp color) (eql 3 (length color)))
       color)
      ((or (string-match "^#" color)
 	  (string-match "^rgb:" color))