From 4940b308ca62257acb79dc4a5a240dc76c780a06 Mon Sep 17 00:00:00 2001 From: Mel Date: Tue, 3 Jun 2025 22:02:36 +0200 Subject: Return, break, continue & defer statement parsing Signed-off-by: Mel --- boot/parse.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++------- boot/tree.c | 45 ++++++++++++++++++++++++++++++++ 2 files changed, 120 insertions(+), 10 deletions(-) diff --git a/boot/parse.c b/boot/parse.c index 9f10d27..94b1e91 100644 --- a/boot/parse.c +++ b/boot/parse.c @@ -711,6 +711,65 @@ parser_statement_loop(struct Parser* p, struct Parser_Error* error) return statement_new(STATEMENT_LOOP, value, span, for_token.location); } +struct Statement* +parser_statement_block(struct Parser* p, struct Parser_Error* error) +{ + struct Block_Node block = CHECK(parser_block_node(p, error)); + return statement_new( + STATEMENT_BLOCK, (union Statement_Value){ .block = { block } }, block.span, block.location); +} + +struct Statement* +parser_statement_return(struct Parser* p, struct Parser_Error* error) +{ + struct Token return_token = CHECK(parser_need(p, TOKEN_WORD_RETURN, error)); + + struct Expression* value = nil; + if (!token_ends_statement(&return_token)) { value = CHECK(parser_expression(p, error)); } + + struct Span span = value ? return_token.span : span_merge(return_token.span, value->span); + union Statement_Value statement_value = { .return_value = { value } }; + return statement_new(STATEMENT_RETURN, statement_value, span, return_token.location); +} + +struct Statement* +parser_statement_break(struct Parser* p, struct Parser_Error* error) +{ + struct Token break_token = CHECK(parser_need(p, TOKEN_WORD_BREAK, error)); + struct Span span = break_token.span; + return statement_new(STATEMENT_BREAK, (union Statement_Value){ 0 }, span, break_token.location); +} + +struct Statement* +parser_statement_continue(struct Parser* p, struct Parser_Error* error) +{ + struct Token continue_token = CHECK(parser_need(p, TOKEN_WORD_CONTINUE, error)); + struct Span span = continue_token.span; + return statement_new( + STATEMENT_CONTINUE, (union Statement_Value){ 0 }, span, continue_token.location); +} + +struct Statement* +parser_statement_defer(struct Parser* p, struct Parser_Error* error) +{ + struct Token defer_token = CHECK(parser_need(p, TOKEN_WORD_DEFER, error)); + + struct Span span = defer_token.span; + struct Statement_Value_Defer defer = { 0 }; + if (parser_probe(p, TOKEN_CURLY_OPEN)) { + struct Block_Node block = CHECK(parser_block_node(p, error)); + span = span_merge(span, block.span); + defer.block = block; + } else { + struct Expression* expression = CHECK(parser_expression(p, error)); + span = span_merge(span, expression->span); + defer.expression = expression; + } + + union Statement_Value value = { .defer = defer }; + return statement_new(STATEMENT_DEFER, value, span, defer_token.location); +} + struct Statement* parser_statement(struct Parser* p, struct Parser_Error* error) { @@ -724,16 +783,22 @@ parser_statement(struct Parser* p, struct Parser_Error* error) if (parser_could_be_variable_declaration(p)) return parser_statement_declaration(p, error); - if (token_is(&token, TOKEN_WORD_IF)) return parser_statement_conditional(p, error); - - if (token_is(&token, TOKEN_WORD_FOR)) return parser_statement_loop(p, error); - - if (token_is(&token, TOKEN_CURLY_OPEN)) { - // a block statement. - struct Block_Node block = CHECK(parser_block_node(p, error)); - return statement_new( - STATEMENT_BLOCK, (union Statement_Value){ .block = { block } }, block.span, - block.location); + switch (token.kind) { + case TOKEN_WORD_IF: + return parser_statement_conditional(p, error); + case TOKEN_WORD_FOR: + return parser_statement_loop(p, error); + case TOKEN_CURLY_OPEN: + return parser_statement_block(p, error); + case TOKEN_WORD_RETURN: + return parser_statement_return(p, error); + case TOKEN_WORD_BREAK: + return parser_statement_break(p, error); + case TOKEN_WORD_CONTINUE: + return parser_statement_continue(p, error); + case TOKEN_WORD_DEFER: + return parser_statement_defer(p, error); + default: break; } struct Expression* expression = CHECK(parser_expression(p, error)); diff --git a/boot/tree.c b/boot/tree.c index 2d49a2c..6e7fd6a 100644 --- a/boot/tree.c +++ b/boot/tree.c @@ -657,6 +657,10 @@ enum Statement_Kind STATEMENT_BLOCK, STATEMENT_CONDITIONAL, STATEMENT_LOOP, + STATEMENT_RETURN, + STATEMENT_BREAK, + STATEMENT_CONTINUE, + STATEMENT_DEFER, }; struct Statement_Value_Expression @@ -701,6 +705,20 @@ struct Statement_Value_Loop struct Block_Node body; }; +struct Statement_Value_Return +{ + // nil if there is no return value. + struct Expression* value; +}; + +struct Statement_Value_Defer +{ + // either a simple expression, or, if expression is nil, + // a block of code to execute. + struct Expression* expression; + struct Block_Node block; +}; + union Statement_Value { struct Statement_Value_Expression expression; @@ -708,6 +726,8 @@ union Statement_Value struct Statement_Value_Block block; struct Statement_Value_Conditional conditional; struct Statement_Value_Loop loop; + struct Statement_Value_Return return_value; + struct Statement_Value_Defer defer; }; struct Statement @@ -832,6 +852,31 @@ statement_print(const struct Statement* statement) block_node_print(&statement->value.loop.body); break; } + case STATEMENT_RETURN: { + printf("(return"); + if (statement->value.return_value.value) { + printf(" "); + expression_print(statement->value.return_value.value); + } + printf(")"); + break; + } + case STATEMENT_BREAK: + printf("(break)"); + break; + case STATEMENT_CONTINUE: + printf("(continue)"); + break; + case STATEMENT_DEFER: { + printf("(defer "); + if (statement->value.defer.expression) { + expression_print(statement->value.defer.expression); + } else { + block_node_print(&statement->value.defer.block); + } + printf(")"); + break; + } default: failure("unexpected statement kind passed to `statement_print`"); break; -- cgit 1.4.1