From: Stefan Monnier <monnier@iro.umontreal.ca>
Date: Sun, 16 Nov 2014 04:59:50 +0000 (-0500)
Subject: * lisp/emacs-lisp/backquote.el (backquote-process): Optimize away the ,' case.
X-Git-Tag: emacs-25.0.90~2635^2~461
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=86009dd5d886f1101358990e4f8f69a5d1467eb8;p=emacs.git

* lisp/emacs-lisp/backquote.el (backquote-process): Optimize away the ,' case.
---

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 5eb4e3a8a7a..634412ec989 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2014-11-16  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* emacs-lisp/backquote.el (backquote-process): Optimize away the ,' case.
+
 2014-11-15  Lars Magne Ingebrigtsen  <larsi@gnus.org>
 
 	* net/eww.el (eww-search-words): Mention `eww-search-prefix'.
@@ -11,8 +15,8 @@
 
 	* progmodes/python.el (python-shell-font-lock-kill-buffer):
 	(python-shell-font-lock-with-font-lock-buffer)
-	(python-shell-get-buffer, python-ffap-module-path): Use
-	`derived-mode-p' instead of equality test on `major-mode'.
+	(python-shell-get-buffer, python-ffap-module-path):
+	Use `derived-mode-p' instead of equality test on `major-mode'.
 
 2014-11-14  Fabián Ezequiel Gallina  <fgallina@gnu.org>
 
diff --git a/lisp/emacs-lisp/backquote.el b/lisp/emacs-lisp/backquote.el
index a497acd637e..5cecbcd4335 100644
--- a/lisp/emacs-lisp/backquote.el
+++ b/lisp/emacs-lisp/backquote.el
@@ -148,16 +148,19 @@ LEVEL is only used internally and indicates the nesting level:
 		 (t
 		  (list 'apply '(function vector) (cdr n))))))))
    ((atom s)
+    ;; FIXME: Use macroexp-quote!
     (cons 0 (if (or (null s) (eq s t) (not (symbolp s)))
 		s
 	      (list 'quote s))))
    ((eq (car s) backquote-unquote-symbol)
     (if (<= level 0)
-        (if (> (length s) 2)
-            ;; We could support it with: (cons 2 `(list . ,(cdr s)))
-            ;; But let's not encourage such uses.
-            (error "Multiple args to , are not supported: %S" s)
-          (cons 1 (nth 1 s)))
+        (cond
+         ((> (length s) 2)
+          ;; We could support it with: (cons 2 `(list . ,(cdr s)))
+          ;; But let's not encourage such uses.
+          (error "Multiple args to , are not supported: %S" s))
+         (t (cons (if (eq (car-safe (nth 1 s)) 'quote) 0 1)
+                  (nth 1 s))))
       (backquote-delay-process s (1- level))))
    ((eq (car s) backquote-splice-symbol)
     (if (<= level 0)
@@ -215,9 +218,7 @@ LEVEL is only used internally and indicates the nesting level:
       ;; Tack on any initial elements.
       (if firstlist
 	  (setq expression (backquote-listify firstlist (cons 1 expression))))
-      (if (eq (car-safe expression) 'quote)
-	  (cons 0 (list 'quote s))
-	(cons 1 expression))))))
+      (cons (if (eq (car-safe expression) 'quote) 0 1) expression)))))
 
 ;; backquote-listify takes (tag . structure) pairs from backquote-process
 ;; and decides between append, list, backquote-list*, and cons depending