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fix else-if parsing

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implicit semicolon rules apply recursively to the "else" clause of if and try

if (a) {} else {} // implicit semicolon
if (a) {} else if (a) {} // implicit semicolon
if (a) {} else while (a) {} // implicit semicolon
This commit is contained in:
Josh Wolfe 2017-04-02 15:14:35 -07:00
parent a33be6fc99
commit 0594487a2e
2 changed files with 19 additions and 10 deletions
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6
doc/langref.md
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@ -93,11 +93,11 @@ Defer(body) = option("%" | "?") "defer" body
IfExpression(body) = IfVarExpression(body) | IfBoolExpression(body)
IfBoolExpression(body) = "if" "(" Expression ")" body option("else" body)
IfBoolExpression(body) = "if" "(" Expression ")" body option("else" BlockExpression(body))
TryExpression(body) = "try" "(" option(("const" | "var") option("*") Symbol "=") Expression ")" body option("else" option("|" Symbol "|") body)
TryExpression(body) = "try" "(" option(("const" | "var") option("*") Symbol "=") Expression ")" body option("else" option("|" Symbol "|") BlockExpression(body))
IfVarExpression(body) = "if" "(" ("const" | "var") option("*") Symbol option(":" TypeExpr) "?=" Expression ")" body Option("else" body)
IfVarExpression(body) = "if" "(" ("const" | "var") option("*") Symbol option(":" TypeExpr) "?=" Expression ")" body Option("else" BlockExpression(body))
BoolAndExpression = ComparisonExpression "and" BoolAndExpression | ComparisonExpression

23
src/parser.cpp
View File

@ -212,6 +212,7 @@ static void ast_invalid_token_error(ParseContext *pc, Token *token) {
}
static AstNode *ast_parse_block_or_expression(ParseContext *pc, size_t *token_index, bool mandatory);
static AstNode *ast_parse_block_expr_or_expression(ParseContext *pc, size_t *token_index, bool mandatory);
static AstNode *ast_parse_expression(ParseContext *pc, size_t *token_index, bool mandatory);
static AstNode *ast_parse_block(ParseContext *pc, size_t *token_index, bool mandatory);
static AstNode *ast_parse_if_expr(ParseContext *pc, size_t *token_index, bool mandatory);
@ -701,7 +702,7 @@ static AstNode *ast_parse_try_expr(ParseContext *pc, size_t *token_index, bool m
ast_eat_token(pc, token_index, TokenIdBinOr);
}
node->data.try_expr.else_node = ast_parse_block_or_expression(pc, token_index, true);
node->data.try_expr.else_node = ast_parse_block_expr_or_expression(pc, token_index, true);
}
return node;
@ -1439,7 +1440,7 @@ static AstNode *ast_parse_if_expr(ParseContext *pc, size_t *token_index, bool ma
Token *else_token = &pc->tokens->at(*token_index);
if (else_token->id == TokenIdKeywordElse) {
*token_index += 1;
node->data.if_var_expr.else_node = ast_parse_block_or_expression(pc, token_index, true);
node->data.if_var_expr.else_node = ast_parse_block_expr_or_expression(pc, token_index, true);
}
return node;
@ -1452,7 +1453,7 @@ static AstNode *ast_parse_if_expr(ParseContext *pc, size_t *token_index, bool ma
Token *else_token = &pc->tokens->at(*token_index);
if (else_token->id == TokenIdKeywordElse) {
*token_index += 1;
node->data.if_bool_expr.else_node = ast_parse_block_or_expression(pc, token_index, true);
node->data.if_bool_expr.else_node = ast_parse_block_expr_or_expression(pc, token_index, true);
}
return node;
@ -1860,15 +1861,15 @@ static bool statement_has_block_body(AstNode *node) {
switch (node->type) {
case NodeTypeIfBoolExpr:
if (node->data.if_bool_expr.else_node)
return node->data.if_bool_expr.else_node->type == NodeTypeBlock;
return statement_has_block_body(node->data.if_bool_expr.else_node);
return node->data.if_bool_expr.then_block->type == NodeTypeBlock;
case NodeTypeIfVarExpr:
if (node->data.if_var_expr.else_node)
return node->data.if_var_expr.else_node->type == NodeTypeBlock;
return statement_has_block_body(node->data.if_var_expr.else_node);
return node->data.if_var_expr.then_block->type == NodeTypeBlock;
case NodeTypeTryExpr:
if (node->data.try_expr.else_node)
return node->data.try_expr.else_node->type == NodeTypeBlock;
return statement_has_block_body(node->data.try_expr.else_node);
return node->data.try_expr.then_node->type == NodeTypeBlock;
case NodeTypeWhileExpr:
return node->data.while_expr.body->type == NodeTypeBlock;
@ -1882,7 +1883,7 @@ static bool statement_has_block_body(AstNode *node) {
case NodeTypeDefer:
return node->data.defer.expr->type == NodeTypeBlock;
default:
zig_unreachable();
return false;
}
}
@ -2030,6 +2031,14 @@ static AstNode *ast_parse_ass_expr(ParseContext *pc, size_t *token_index, bool m
return node;
}
static AstNode *ast_parse_block_expr_or_expression(ParseContext *pc, size_t *token_index, bool mandatory) {
AstNode *block_expr = ast_parse_block_expr(pc, token_index, false);
if (block_expr)
return block_expr;
return ast_parse_expression(pc, token_index, mandatory);
}
/*
BlockOrExpression = Block | Expression
*/