Add serd_node_compare()

1 files changed, 28 insertions, 0 deletions

diff --git a/src/node.c b/src/node.c
index 859cb0a3..b0e8f991 100644
--- a/src/node.c
+++ b/src/node.c
@@ -66,6 +66,14 @@ serd_node_pad_size(const size_t n_bytes)
 }
 
 static const SerdNode*
+serd_node_maybe_get_meta_c(const SerdNode* node)
+{
+	return (node->flags & (SERD_HAS_LANGUAGE | SERD_HAS_DATATYPE))
+		? (node + 1 + (serd_node_pad_size(node->n_bytes) / serd_node_align))
+		: NULL;
+}
+
+static const SerdNode*
 serd_node_get_meta_c(const SerdNode* node)
 {
 	return node + 1 + (serd_node_pad_size(node->n_bytes) / serd_node_align);
@@ -303,6 +311,26 @@ serd_node_equals(const SerdNode* a, const SerdNode* b)
 	return false;
 }
 
+int
+serd_node_compare(const SerdNode* a, const SerdNode* b)
+{
+	if (a == b) {
+		return 0;
+	} else if (!a || !b) {
+		return (a < b) ? -1 : (a > b) ? 1 : 0;
+	} else if (a->type != b->type) {
+		return a->type - b->type;
+	}
+
+	const int cmp = strcmp(serd_node_get_string(a), serd_node_get_string(b));
+	if (cmp) {
+		return cmp;
+	}
+
+	return serd_node_compare(serd_node_maybe_get_meta_c(a),
+	                         serd_node_maybe_get_meta_c(b));
+}
+
 static size_t
 serd_uri_string_length(const SerdURI* uri)
 {