motiejus/zig
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change while syntax

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Old:

```
while (condition; expression) {}
```

New:

```
while (condition) : (expression) {}
```

This is in preparation to allow nullable and
error union types as the condition. See #357
This commit is contained in:
Andrew Kelley
2017-05-03 18:12:07 -04:00
parent 644ea2dde9
commit 698829b772
25 changed files with 100 additions and 68 deletions
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52
src/parser.cpp
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@@ -1580,7 +1580,7 @@ static AstNode *ast_parse_bool_or_expr(ParseContext *pc, size_t *token_index, bo
}
/*
WhileExpression(body) = option("inline") "while" "(" Expression option(";" Expression) ")" body
WhileExpression(body) = option("inline") "while" "(" Expression ")" option("|" option("*") Symbol "|") option(":" "(" Expression ")") body option("else" option("|" Symbol "|") BlockExpression(body))
*/
static AstNode *ast_parse_while_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *first_token = &pc->tokens->at(*token_index);
@@ -1613,21 +1613,49 @@ static AstNode *ast_parse_while_expr(ParseContext *pc, size_t *token_index, bool
ast_eat_token(pc, token_index, TokenIdLParen);
node->data.while_expr.condition = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
Token *semi_or_rparen = &pc->tokens->at(*token_index);
Token *open_bar_tok = &pc->tokens->at(*token_index);
if (open_bar_tok->id == TokenIdBinOr) {
*token_index += 1;
if (semi_or_rparen->id == TokenIdRParen) {
*token_index += 1;
node->data.while_expr.body = ast_parse_block_or_expression(pc, token_index, true);
} else if (semi_or_rparen->id == TokenIdSemicolon) {
*token_index += 1;
node->data.while_expr.continue_expr = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
node->data.while_expr.body = ast_parse_block_or_expression(pc, token_index, true);
} else {
ast_invalid_token_error(pc, semi_or_rparen);
Token *star_tok = &pc->tokens->at(*token_index);
if (star_tok->id == TokenIdStar) {
*token_index += 1;
node->data.while_expr.var_is_ptr = true;
}
Token *var_name_tok = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.while_expr.var_symbol = token_buf(var_name_tok);
ast_eat_token(pc, token_index, TokenIdBinOr);
}
Token *colon_tok = &pc->tokens->at(*token_index);
if (colon_tok->id == TokenIdColon) {
*token_index += 1;
ast_eat_token(pc, token_index, TokenIdLParen);
node->data.while_expr.continue_expr = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
}
node->data.while_expr.body = ast_parse_block_or_expression(pc, token_index, true);
Token *else_tok = &pc->tokens->at(*token_index);
if (else_tok->id == TokenIdKeywordElse) {
*token_index += 1;
Token *else_bar_tok = &pc->tokens->at(*token_index);
if (else_bar_tok->id == TokenIdBinOr) {
*token_index += 1;
Token *err_name_tok = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.while_expr.err_symbol = token_buf(err_name_tok);
ast_eat_token(pc, token_index, TokenIdBinOr);
}
node->data.while_expr.body = ast_parse_block_or_expression(pc, token_index, true);
}
return node;
}