lang: ast: re-write expression parser to support keyword messages

also adjust some parser state callbackss to better support sub-parsers returning
 results to their parents.

lang/ast/ctx.c

@@ -5,9 +5,21 @@
 #include <blue/core/queue.h>
 #include <ivy/lang/ast.h>
 #include <stddef.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
+static void print_state_stack(struct ivy_parser *parser)
+{
+	b_queue_iterator it = {0};
+	b_queue_foreach (&it, &parser->p_state) {
+		struct parser_state *state
+			= b_unbox(struct parser_state, it.entry, s_entry);
+		printf("  %s\n",
+		       ivy_ast_node_type_to_string(state->s_node->n_type));
+	}
+}
+
 enum ivy_status ivy_parser_create(struct ivy_parser **parser)
 {
 	struct ivy_parser *out = malloc(sizeof *out);
@@ -48,6 +60,9 @@ enum ivy_status ivy_parser_push_token(
 			struct token_parse_result result = func(parser, tok);
 			parser->p_status = result.r_status;
 
+			printf("states (after token)\n");
+			print_state_stack(parser);
+
 			if (result.r_flags & PARSE_REPEAT_TOKEN) {
 				continue;
 			}
@@ -108,6 +123,8 @@ struct parser_state *parser_push_state(
 		node_type->n_init_state(parser, state);
 	}
 
+	printf("states (after push)\n");
+	print_state_stack(parser);
 	return state;
 }
 
@@ -122,13 +139,17 @@ void parser_pop_state(struct ivy_parser *parser, enum pop_state_flags flags)
 	b_queue_pop_back(&parser->p_state);
 
 	if (state && (flags & STATE_ADD_NODE_TO_PARENT)) {
-		ast_node_add_child(state->s_parent, state->s_node);
+		parser_add_child(parser, state->s_node);
 	}
 
 	free(state);
+
+	printf("states (after pop)\n");
+	print_state_stack(parser);
 }
 
-void parser_replace_current_node(struct ivy_parser *parser, struct ivy_ast_node *new_node)
+void parser_replace_current_node(
+	struct ivy_parser *parser, struct ivy_ast_node *new_node)
 {
 	struct parser_state *state = parser_get_state_generic(parser);
 	if (!state) {
@@ -139,6 +160,23 @@ void parser_replace_current_node(struct ivy_parser *parser, struct ivy_ast_node
 	state->s_node = new_node;
 }
 
+enum ivy_status parser_add_child(
+	struct ivy_parser *parser, struct ivy_ast_node *new_node)
+{
+	struct parser_state *state = parser_get_state_generic(parser);
+	if (!state) {
+		return IVY_ERR_NOT_SUPPORTED;
+	}
+
+	const struct ast_node_type *node_type
+		= get_ast_node_type(state->s_node->n_type);
+	if (!node_type || !node_type->n_add_child) {
+		return IVY_ERR_NOT_SUPPORTED;
+	}
+
+	return node_type->n_add_child(state, new_node);
+}
+
 bool ivy_parser_is_node_complete(struct ivy_parser *parser)
 {
 	return (parser->p_state.q_first == parser->p_state.q_last);