* lisp/emacs-lisp/subr-x.el: (string-remove-prefix): New function.

(string-remove-suffix): New function.

etc/NEWS

@@ -885,6 +885,8 @@ frame.
 *** `string-trim-left'
 *** `string-trim-right'
 *** `string-trim'
+*** `string-remove-prefix'
+*** `string-remove-suffix'
 
 ** Obsoleted functions:
 *** `log10'

lisp/ChangeLog

@@ -2,6 +2,8 @@
 
 	* emacs-lisp/subr-x.el: Renamed from helpers.el.
 	helpers.el was a poor choice of name.
+	(string-remove-prefix): New function.
+	(string-remove-suffix): New function.
 
 2013-12-20  Martin Rudalics  <rudalics@gmx.at>
 

lisp/emacs-lisp/subr-x.el

@@ -73,6 +73,18 @@
   "Check whether STRING is either empty or only whitespace."
   (string-match-p "\\`[ \t\n\r]*\\'" string))
 
+(defsubst string-remove-prefix (prefix string)
+  "Remove PREFIX from STRING if present."
+  (if (string-prefix-p prefix string)
+      (substring string (length prefix))
+    string))
+
+(defsubst string-remove-suffix (suffix string)
+  "Remove SUFFIX from STRING if present."
+  (if (string-suffix-p suffix string)
+      (substring string 0 (- (length string) (length suffix)))
+    string))
+
 (provide 'subr-x)
 
 ;;; subr-x.el ends here