src/ast.c

@@ -188,3 +188,18 @@ static void ast_node_print_internal(ast_node_t *node, int indent) {
 void ast_node_print(ast_node_t *node) {
     ast_node_print_internal(node, 0);
 }
+
+void ast_node_prune(ast_node_t *node, node_id_t id) {
+    size_t new_len = 0;
+    for (size_t i = 0; i < node->len; i++) {
+        auto child = node->children[i];
+        if (child->id == id) {
+            ast_node_free(child);
+            continue;
+        }
+        ast_node_prune(child, id);
+        node->children[new_len] = child;
+        new_len++;
+    }
+    node->len = new_len;
+}

src/ast.h

@@ -120,4 +120,17 @@ error_t *ast_node_add_child(ast_node_t *node, ast_node_t *child);
  */
 void ast_node_print(ast_node_t *node);
 
+/**
+ * Prune the children with a given id
+ *
+ * The tree is recursively visited and all child nodes of a given ID are pruned
+ * completely. If a node has the giver id, it will get removed along wih all its
+ * children, even if some of those children have different ids. The root node id
+ * is never checked so the tree is guaranteed to remain and allocated valid.
+ *
+ * @param node The root of the tree you want to prune
+ * @param id The id of the nodes you want to prune
+ */
+void ast_node_prune(ast_node_t *node, node_id_t id);
+
 #endif // INCLUDE_SRC_AST_H_

src/parser/parser.c

@@ -139,5 +139,9 @@ parse_result_t parse_statement(tokenlist_entry_t *current) {
 
 parse_result_t parse(tokenlist_entry_t *current) {
     current = tokenlist_skip_trivia(current);
-    return parse_many(current, NODE_PROGRAM, true, parse_statement);
+    parse_result_t result =
+        parse_many(current, NODE_PROGRAM, true, parse_statement);
+    if (result.node != nullptr)
+        ast_node_prune(result.node, NODE_NEWLINE);
+    return result;
 }