-slist *add_slist PARAMS ((slist *, const char *, int));
-int in_slist PARAMS ((slist *, const char *));
-void free_slist PARAMS ((slist *));
+slist *slist_append PARAMS ((slist *, const char *));
+slist *slist_prepend PARAMS ((slist *, const char *));
+slist *slist_nreverse PARAMS ((slist *));
+int slist_contains PARAMS ((slist *, const char *));
+void slist_free PARAMS ((slist *));
+
+void string_set_add PARAMS ((struct hash_table *, const char *));
+int string_set_contains PARAMS ((struct hash_table *, const char *));
+void string_set_free PARAMS ((struct hash_table *));
+void free_keys_and_values PARAMS ((struct hash_table *));