tag: added function tag_has_type()

tag_has_type() checks whether the tag contains one or more items with
the specified type.

src/tag.c

@@ -319,6 +319,18 @@ struct tag *tag_dup(const struct tag *tag)
 	return ret;
 }
 
+bool tag_has_type(const struct tag *tag, enum tag_type type)
+{
+	assert(tag != NULL);
+	assert(type < TAG_NUM_OF_ITEM_TYPES);
+
+	for (unsigned i = 0; i < tag->numOfItems; i++)
+		if (tag->items[i]->type == type)
+			return true;
+
+	return false;
+}
+
 int tag_equal(const struct tag *tag1, const struct tag *tag2)
 {
 	int i;

src/tag.h

@@ -23,6 +23,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include <stdbool.h>
 #include <string.h>
 
 enum tag_type {
@@ -88,6 +89,12 @@ static inline void tag_add_item(struct tag *tag, enum tag_type itemType,
 
 struct tag *tag_dup(const struct tag *tag);
 
+/**
+ * Checks whether the tag contains one or more items with
+ * the specified type.
+ */
+bool tag_has_type(const struct tag *tag, enum tag_type type);
+
 int tag_equal(const struct tag *tag1, const struct tag *tag2);
 
 #endif