string-list: new for_each_string_list() function

Add a convenience function for iterating over a string_list's items via
a callback.

Signed-off-by: Jay Soffian <jaysoffian@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

string-list.c

@@ -92,6 +92,16 @@ struct string_list_item *string_list_lookup(const char *string, struct string_li
 	return list->items + i;
 }
 
+int for_each_string_list(string_list_each_func_t fn,
+			 struct string_list *list, void *cb_data)
+{
+	int i, ret = 0;
+	for (i = 0; i < list->nr; i++)
+		if ((ret = fn(&list->items[i], cb_data)))
+			break;
+	return ret;
+}
+
 void string_list_clear(struct string_list *list, int free_util)
 {
 	if (list->items) {

string-list.h

@@ -20,6 +20,11 @@ void string_list_clear(struct string_list *list, int free_util);
 typedef void (*string_list_clear_func_t)(void *p, const char *str);
 void string_list_clear_func(struct string_list *list, string_list_clear_func_t clearfunc);
 
+/* Use this function to iterate over each item */
+typedef int (*string_list_each_func_t)(struct string_list_item *, void *);
+int for_each_string_list(string_list_each_func_t,
+			 struct string_list *list, void *cb_data);
+
 /* Use these functions only on sorted lists: */
 int string_list_has_string(const struct string_list *list, const char *string);
 int string_list_find_insert_index(const struct string_list *list, const char *string,