From 8c56ddf0b640b8880eb5b97e5ca1b787585c29c0 Mon Sep 17 00:00:00 2001 From: Johnny Richard Date: Mon, 1 May 2023 01:57:21 +0200 Subject: parser: Use peek and drop token when parsing expressions --- src/lexer.c | 7 +++---- src/lexer.h | 2 +- src/parser.c | 16 ++++++++-------- 3 files changed, 12 insertions(+), 13 deletions(-) diff --git a/src/lexer.c b/src/lexer.c index f937170..b60fbb5 100644 --- a/src/lexer.c +++ b/src/lexer.c @@ -232,11 +232,10 @@ lexer_peek_next_token(lexer_t *lexer, token_t *token) } void -lexer_step_back_to(lexer_t *lexer, token_t *token) +lexer_drop_next_token(lexer_t *lexer) { - lexer->cur = token->bol + token->col; - lexer->row = token->row; - lexer->bol = token->bol; + token_t token; + lexer_next_token(lexer, &token); } void diff --git a/src/lexer.h b/src/lexer.h index 0b9f2ad..abee53a 100644 --- a/src/lexer.h +++ b/src/lexer.h @@ -83,7 +83,7 @@ void lexer_drop_char(lexer_t *lexer); void -lexer_step_back_to(lexer_t *lexer, token_t *token); +lexer_drop_next_token(lexer_t *lexer); void lexer_peek_next_token(lexer_t *lexer, token_t *token); diff --git a/src/parser.c b/src/parser.c index 662449b..af372fb 100644 --- a/src/parser.c +++ b/src/parser.c @@ -167,9 +167,11 @@ parser_parse_term(parser_t *parser, ast_node_t *node) return false; token_t token; - lexer_next_token(parser->lexer, &token); + lexer_peek_next_token(parser->lexer, &token); while (token.kind == TOKEN_STAR || token.kind == TOKEN_SLASH) { + lexer_drop_next_token(parser->lexer); + ast_node_t *left = ast_node_new(); *left = *node; @@ -179,11 +181,9 @@ parser_parse_term(parser_t *parser, ast_node_t *node) ast_node_init_binary_operation(node, token_to_binary_operation_kind(&token), left, right); - lexer_next_token(parser->lexer, &token); + lexer_peek_next_token(parser->lexer, &token); } - lexer_step_back_to(parser->lexer, &token); - return true; } @@ -201,9 +201,11 @@ parser_parse_expression(parser_t *parser, ast_node_t *node) return false; token_t token; - lexer_next_token(parser->lexer, &token); + lexer_peek_next_token(parser->lexer, &token); while (token.kind == TOKEN_PLUS || token.kind == TOKEN_MINUS) { + lexer_drop_next_token(parser->lexer); + ast_node_t *left = ast_node_new(); *left = *node; @@ -213,11 +215,9 @@ parser_parse_expression(parser_t *parser, ast_node_t *node) ast_node_init_binary_operation(node, token_to_binary_operation_kind(&token), left, right); - lexer_next_token(parser->lexer, &token); + lexer_peek_next_token(parser->lexer, &token); } - lexer_step_back_to(parser->lexer, &token); - return true; } -- cgit v1.2.3