* lisp/emacs-lisp/rx.el (rx-constituents): Don't define as constant.

(rx-form): Simplify.

2 files changed, 30 insertions, 22 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index c715059c135..c2e45204026 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2012-08-10  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * emacs-lisp/rx.el (rx-constituents): Don't define as constant.
+        (rx-form): Simplify.
+
 2012-08-09  Dmitry Gutov  <dgutov@yandex.ru>
 
         Merge stuff from upsteam ruby-mode, part 1 (bug#12169).
diff --git a/lisp/emacs-lisp/rx.el b/lisp/emacs-lisp/rx.el
index a0fb15ae39f..774c6cd2c38 100644
--- a/lisp/emacs-lisp/rx.el
+++ b/lisp/emacs-lisp/rx.el
@@ -107,7 +107,9 @@
 
 ;;; Code:
 
-(defconst rx-constituents
+;; FIXME: support macros.
+
+(defvar rx-constituents              ;Not `const' because some modes extend it.
   '((and                . (rx-and 1 nil))
     (seq                . and)          ; SRE
     (:                  . and)          ; SRE
@@ -831,27 +833,28 @@ If FORM is '(minimal-match FORM1)', non-greedy versions of `*',
 FORM is a regular expression in sexp form.
 RX-PARENT shows which type of expression calls and controls putting of
 shy groups around the result and some more in other functions."
-  (if (stringp form)
-      (rx-group-if (regexp-quote form)
-                   (if (and (eq rx-parent '*) (< 1 (length form)))
-                       rx-parent))
-    (cond ((integerp form)
-           (regexp-quote (char-to-string form)))
-          ((symbolp form)
-           (let ((info (rx-info form nil)))
-             (cond ((stringp info)
-                    info)
-                   ((null info)
-                    (error "Unknown rx form `%s'" form))
-                   (t
-                    (funcall (nth 0 info) form)))))
-          ((consp form)
-           (let ((info (rx-info (car form) 'head)))
-             (unless (consp info)
-               (error "Unknown rx form `%s'" (car form)))
-             (funcall (nth 0 info) form)))
-          (t
-           (error "rx syntax error at `%s'" form)))))
+  (cond
+   ((stringp form)
+    (rx-group-if (regexp-quote form)
+                 (if (and (eq rx-parent '*) (< 1 (length form)))
+                     rx-parent)))
+   ((integerp form)
+    (regexp-quote (char-to-string form)))
+   ((symbolp form)
+    (let ((info (rx-info form nil)))
+      (cond ((stringp info)
+             info)
+            ((null info)
+             (error "Unknown rx form `%s'" form))
+            (t
+             (funcall (nth 0 info) form)))))
+   ((consp form)
+    (let ((info (rx-info (car form) 'head)))
+      (unless (consp info)
+        (error "Unknown rx form `%s'" (car form)))
+      (funcall (nth 0 info) form)))
+   (t
+    (error "rx syntax error at `%s'" form))))
 
 
 ;;;###autoload