From 54c6fd7040de9582c9c3688ae97e3c84c7fb6f0b Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Fri, 6 Dec 2024 22:24:08 +0000
Subject: [PATCH] lang: ast: adjust and clarify the precedence of token parser
 callbacks

---
 lang/ast/node.c | 59 +++++++++++++++++++++++++++++++------------------
 1 file changed, 38 insertions(+), 21 deletions(-)

diff --git a/lang/ast/node.c b/lang/ast/node.c
index 4cdeb89..e7f6cc6 100644
--- a/lang/ast/node.c
+++ b/lang/ast/node.c
@@ -117,34 +117,38 @@ enum token_expr_type get_token_expr_type(struct ivy_token *tok)
 token_parse_function get_token_parser(
 	struct ivy_ast_node *context, struct ivy_token *tok)
 {
+	token_parse_function type_parser = NULL;
+	token_parse_function type_fallback_parser = NULL;
+	token_parse_function token_parser = NULL;
+	token_parse_function expr_begin_parser = NULL;
+	token_parse_function expr_other_parser = NULL;
+	token_parse_function expr_parser = NULL;
+	token_parse_function token_fallback_parser = NULL;
+
 	const struct ast_node_type *type = get_ast_node_type(context->n_type);
 	if (!type) {
 		return NULL;
 	}
-	token_parse_function generic_parser
-		= type->n_token_parsers[__TOK_PARSER_INDEX(tok->t_type)];
 
-	if (!generic_parser) {
-		generic_parser
-			= type->n_token_parsers[__TOK_PARSER_FALLBACK_INDEX];
-	}
+	token_parser = type->n_token_parsers[__TOK_PARSER_INDEX(tok->t_type)];
+	token_fallback_parser = type->n_token_parsers[__TOK_PARSER_FALLBACK_INDEX];
 
 	token_parse_function better_parser = NULL;
 
 	switch (tok->t_type) {
 	case IVY_TOK_KEYWORD:
-		better_parser
+		type_parser
 			= type->n_keyword_parsers[__KW_PARSER_INDEX(tok->t_keyword)];
 		if (type->n_keyword_parsers[__KW_PARSER_FALLBACK_INDEX]) {
-			generic_parser
+			type_fallback_parser
 				= type->n_keyword_parsers[__KW_PARSER_FALLBACK_INDEX];
 		}
 		break;
 	case IVY_TOK_SYMBOL:
-		better_parser
+		type_parser
 			= type->n_symbol_parsers[__SYM_PARSER_INDEX(tok->t_symbol)];
 		if (type->n_symbol_parsers[__SYM_PARSER_FALLBACK_INDEX]) {
-			generic_parser
+			type_fallback_parser
 				= type->n_symbol_parsers[__SYM_PARSER_FALLBACK_INDEX];
 		}
 		break;
@@ -152,27 +156,40 @@ token_parse_function get_token_parser(
 		break;
 	}
 
-	if (better_parser) {
-		return better_parser;
-	}
-
 	enum token_expr_type expr_type = get_token_expr_type(tok);
 	switch (expr_type) {
 	case TOK_EXPR_BEGIN:
-		better_parser = type->n_expr_parser.expr_begin
-		                      ? type->n_expr_parser.expr_begin
-		                      : type->n_expr_parser.expr_all;
+		expr_begin_parser = type->n_expr_parser.expr_begin;
+		expr_parser = type->n_expr_parser.expr_all;
 		break;
 	case TOK_EXPR_ANY:
-		better_parser = type->n_expr_parser.expr_other
-		                      ? type->n_expr_parser.expr_other
-		                      : type->n_expr_parser.expr_all;
+		expr_other_parser = type->n_expr_parser.expr_other;
+		expr_parser = type->n_expr_parser.expr_all;
 		break;
 	default:
 		break;
 	}
 
-	return better_parser ? better_parser : generic_parser;
+	bool token_has_sub_id
+		= (tok->t_type == IVY_TOK_KEYWORD || tok->t_type == IVY_TOK_SYMBOL);
+
+	if (type_parser)
+		return type_parser;
+	if (token_parser && !token_has_sub_id)
+		return token_parser;
+	if (expr_begin_parser)
+		return expr_begin_parser;
+	if (expr_other_parser)
+		return expr_other_parser;
+	if (expr_parser)
+		return expr_parser;
+	if (type_fallback_parser)
+		return type_fallback_parser;
+	if (token_parser && token_has_sub_id)
+		return token_parser;
+	if (token_fallback_parser)
+		return token_fallback_parser;
+	return NULL;
 }
 
 struct ivy_ast_node *ast_node_create(enum ivy_ast_node_type type)