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-rw-r--r--map.c22
-rw-r--r--map.h2
2 files changed, 24 insertions, 0 deletions
diff --git a/map.c b/map.c
index 10d39de..f6e5c64 100644
--- a/map.c
+++ b/map.c
@@ -232,6 +232,28 @@ void map_iterate(const Map *map, bool (*handle)(const char *, void *, void *), c
iterate(*map, handle, data);
}
+typedef struct {
+ const char *key;
+ void *value;
+} KeyValue;
+
+static bool first(const char *key, void *value, void *data)
+{
+ KeyValue *kv = data;
+ kv->key = key;
+ kv->value = value;
+ return false;
+}
+
+void *map_first(const Map *map, const char **key)
+{
+ KeyValue kv = { 0 };
+ map_iterate(map, first, &kv);
+ if (key && kv.key)
+ *key = kv.key;
+ return kv.value;
+}
+
const Map *map_prefix(const Map *map, const char *prefix)
{
const Map *n, *top;
diff --git a/map.h b/map.h
index 816e537..ca7bd44 100644
--- a/map.h
+++ b/map.h
@@ -9,6 +9,8 @@ typedef struct Map Map;
Map *map_new(void);
/* Retrieves a value, or NULL if it isn't in the map */
void *map_get(const Map*, const char *key);
+/* Get first element of the map, or NULL if empty */
+void *map_first(const Map*, const char **key);
/* Returns the corresponding value if the given prefix is unique.
* Otherwise NULL, if no such prefix exists then errno is set to ENOENT. */
void *map_closest(const Map*, const char *prefix);