lang: ast: implement cascade operator parsing

lang/ast/cascade.c

@@ -0,0 +1,27 @@
+#include "ctx.h"
+#include "node.h"
+
+#include <stdio.h>
+
+static void collect_children(
+	struct ivy_ast_node *node, struct ivy_ast_node_iterator *iterator)
+{
+	struct ivy_ast_cascade_node *cascade = (struct ivy_ast_cascade_node *)node;
+
+	if (cascade->n_recipient) {
+		ast_node_iterator_enqueue_node(iterator, node, cascade->n_recipient);
+	}
+
+	b_queue_iterator it = {0};
+	b_queue_foreach (&it, &cascade->n_msg) {
+		struct ivy_ast_node *arg
+			= b_unbox(struct ivy_ast_node, it.entry, n_entry);
+		ast_node_iterator_enqueue_node(iterator, node, arg);
+	}
+}
+
+struct ast_node_type cascade_node_ops = {
+	.n_collect_children = collect_children,
+	.n_state_size = sizeof(struct parser_state),
+	.n_node_size = sizeof(struct ivy_ast_cascade_node),
+};