An efficient built-in mapcan

[gnu-emacs] / lisp / progmodes / gud.el

diff --git a/lisp/progmodes/gud.el b/lisp/progmodes/gud.el
index 9bf739463edce7cd8035e19fca1891f9cab8ff41..ceb57b7156dae6f0f3fb9bf96ccfac196b53764b 100644 (file)
--- a/lisp/progmodes/gud.el
+++ b/lisp/progmodes/gud.el
@@ -1947,10 +1947,10 @@ the source code display in sync with the debugging session.")
 PATH gives the directories in which to search for files with
 extension EXTN.  Normally EXTN is given as the regular expression
  \"\\.java$\" ."
-  (apply 'nconc (mapcar (lambda (d)
-                         (when (file-directory-p d)
-                           (directory-files d t extn nil)))
-                       path)))
+  (mapcan (lambda (d)
+            (when (file-directory-p d)
+              (directory-files d t extn nil)))
+          path))
 
 ;; Move point past whitespace.
 (defun gud-jdb-skip-whitespace ()