Add user data field for nodes

3 files changed, 31 insertions, 0 deletions

diff --git a/src/cmark.h b/src/cmark.h
index 04ca6d7..74fa4c7 100644
--- a/src/cmark.h
+++ b/src/cmark.h
@@ -226,6 +226,17 @@ cmark_iter_reset(cmark_iter *iter, cmark_node *current,
  * ## Accessors
  */
 
+/** Returns the user data of 'node'.
+ */
+CMARK_EXPORT void*
+cmark_node_get_user_data(cmark_node *node);
+
+/** Sets arbitrary user data for 'node'.  Returns 1 on success,
+ * 0 on failure.
+ */
+CMARK_EXPORT int
+cmark_node_set_user_data(cmark_node *node, void *user_data);
+
 /** Returns the type of 'node', or `CMARK_NODE_NONE` on error.
  */
 CMARK_EXPORT cmark_node_type
diff --git a/src/node.c b/src/node.c
index 3785a27..675eb19 100644
--- a/src/node.c
+++ b/src/node.c
@@ -189,6 +189,24 @@ cmark_node_last_child(cmark_node *node)
 	}
 }
 
+void*
+cmark_node_get_user_data(cmark_node *node) {
+	if (node == NULL) {
+		return NULL;
+	} else {
+		return node->user_data;
+	}
+}
+
+int
+cmark_node_set_user_data(cmark_node *node, void *user_data) {
+	if (node == NULL) {
+		return 0;
+	}
+	node->user_data = user_data;
+	return 1;
+}
+
 static char*
 S_strdup(const char *str)
 {
diff --git a/src/node.h b/src/node.h
index c0c43d3..74eddd4 100644
--- a/src/node.h
+++ b/src/node.h
@@ -49,6 +49,8 @@ struct cmark_node {
 	struct cmark_node *first_child;
 	struct cmark_node *last_child;
 
+	void *user_data;
+
 	int start_line;
 	int start_column;
 	int end_line;