* emacs-lisp/checkdoc.el (checkdoc-proper-noun-regexp): Build

value with regexp-opt instead of explicit joining loop.  (My
Bug#4927.)

diff --git a/lisp/emacs-lisp/checkdoc.el b/lisp/emacs-lisp/checkdoc.el
index 7140c997283457892a6abc04865e8a39bf50f24d..5e8d2e084ff44242cacd7673f62ac02035335455 100644 (file)
--- a/lisp/emacs-lisp/checkdoc.el
+++ b/lisp/emacs-lisp/checkdoc.el
@@ -334,12 +334,9 @@ This should be set in an Emacs Lisp file's local variables."
   ;; "[.!?]" is for noun at end of a sentence, since those chars
   ;; are symbol syntax in emacs-lisp-mode and so don't match \\_>.
   ;; The \" allows it to be the last sentence in a docstring too.
-  (let ((expr "\\_<\\(")
-       (l checkdoc-proper-noun-list))
-    (while l
-      (setq expr (concat expr (car l) (if (cdr l) "\\|" ""))
-           l (cdr l)))
-    (concat expr "\\)\\(\\_>\\|[.!?][ \t\n\"]\\)"))
+  (concat "\\_<"
+         (regexp-opt checkdoc-proper-noun-list t)
+         "\\(\\_>\\|[.!?][ \t\n\"]\\)")
   "Regular expression derived from `checkdoc-proper-noun-regexp'.")
 
 (defvar checkdoc-common-verbs-regexp nil