Markus Triska <markus.triska at gmx.at>:

(byte-compile-char-before): Improve numeric argument case.
(byte-compile-backward-char, byte-compile-backward-word): New
functions, performing rewriting previously done in byte-opt.el.
Fix their "Fixme" item (restriction to numeric arguments).

1 files changed, 27 insertions, 4 deletions

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index de749e1d0c8..f1761c125ac 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -3149,6 +3149,8 @@ That command is designed for interactive use only" fn))
 ;; more complicated compiler macros
 
 (byte-defop-compiler char-before)
+(byte-defop-compiler backward-char)
+(byte-defop-compiler backward-word)
 (byte-defop-compiler list)
 (byte-defop-compiler concat)
 (byte-defop-compiler fset)
@@ -3162,10 +3164,31 @@ That command is designed for interactive use only" fn))
 
 (defun byte-compile-char-before (form)
   (cond ((= 2 (length form))
-         (byte-compile-form `(char-after (1- ,(nth 1 form)))))
-        ((= 1 (length form))
-         (byte-compile-form '(char-after (1- (point)))))
-        (t (byte-compile-subr-wrong-args form "0-1"))))
+         (byte-compile-form (list 'char-after (if (numberp (nth 1 form))
+                                                  (1- (nth 1 form))
+                                                `(1- ,(nth 1 form))))))
+        ((= 1 (length form))
+         (byte-compile-form '(char-after (1- (point)))))
+        (t (byte-compile-subr-wrong-args form "0-1"))))
+
+;; backward-... ==> forward-... with negated argument.
+(defun byte-compile-backward-char (form)
+  (cond ((= 2 (length form))
+         (byte-compile-form (list 'forward-char (if (numberp (nth 1 form))
+                                                    (- (nth 1 form))
+                                                  `(- ,(nth 1 form))))))
+        ((= 1 (length form))
+         (byte-compile-form '(forward-char -1)))
+        (t (byte-compile-subr-wrong-args form "0-1"))))
+
+(defun byte-compile-backward-word (form)
+  (cond ((= 2 (length form))
+         (byte-compile-form (list 'forward-word (if (numberp (nth 1 form))
+                                                    (- (nth 1 form))
+                                                  `(- ,(nth 1 form))))))
+        ((= 1 (length form))
+         (byte-compile-form '(forward-word -1)))
+        (t (byte-compile-subr-wrong-args form "0-1"))))
 
 (defun byte-compile-list (form)
   (let ((count (length (cdr form))))