From: Mattias Engdegård <mattiase@acm.org>
Date: Fri, 13 Oct 2023 13:21:26 +0000 (+0200)
Subject: Add convenience wrapper for regexp disassembly
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=77daafbb3657d301f864b969cdfe8da17ab5a62d;p=emacs.git

Add convenience wrapper for regexp disassembly

* lisp/emacs-lisp/disass.el (re-disassemble): New.
* etc/NEWS: Describe the new function instead of the internal
`re--describe-compiled`.
---

diff --git a/etc/NEWS b/etc/NEWS
index 0e93faebb84..0f9b5f98ebf 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1018,7 +1018,7 @@ Use 'define-minor-mode' and 'define-globalized-minor-mode' instead.
 
 * Lisp Changes in Emacs 30.1
 
-** New function 're--describe-compiled' to see the innards of a regexp.
+** New function 're-disassemble' to see the innards of a regexp.
 If you compiled with '--enable-checking', you can use this to help debug
 either your regexp performance problems or the regexp engine.
 
diff --git a/lisp/emacs-lisp/disass.el b/lisp/emacs-lisp/disass.el
index 73777d7e701..d9295686e9f 100644
--- a/lisp/emacs-lisp/disass.el
+++ b/lisp/emacs-lisp/disass.el
@@ -301,6 +301,23 @@ OBJ should be a call to BYTE-CODE generated by the byte compiler."
 	  (insert "\n")))))
   nil)
 
+(defun re-disassemble (regexp &optional case-table)
+  "Describe the compiled form of REGEXP in a separate window.
+If CASE-TABLE is non-nil, use it as translation table for case-folding.
+
+This function is mainly intended for maintenance of Emacs itself
+and may change at any time.  It requires Emacs to be built with
+`--enable-checking'."
+  (interactive "XRegexp (Lisp expression): ")
+  (let ((desc (with-temp-buffer
+                (when case-table
+                  (set-case-table case-table))
+                (let ((case-fold-search (and case-table t)))
+                  (re--describe-compiled regexp)))))
+    (with-output-to-temp-buffer "*Regexp-disassemble*"
+      (with-current-buffer standard-output
+        (insert desc)))))
+
 (provide 'disass)
 
 ;;; disass.el ends here