-void language_argmatch (char const *arg, int prio, location const *loc);
-void skeleton_arg (const char *arg, int prio, location const *loc);
+void language_argmatch (char const *arg, int prio, location loc);
+void skeleton_arg (const char *arg, int prio, location loc);
+
+/** In the string \c s, replace all characters \c from by \c to. */
+void tr (char *s, char from, char to);