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update syntax for try and nullable unwrapping

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closes #285
This commit is contained in:
Andrew Kelley
2017-04-21 16:46:33 -04:00
parent d5346d7a80
commit 0cce115476
18 changed files with 219 additions and 295 deletions
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172
src/parser.cpp
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@@ -640,7 +640,7 @@ static AstNode *ast_parse_comptime_expr(ParseContext *pc, size_t *token_index, b
}
/*
TryExpression(body) = "try" "(" option(("const" | "var") option("*") Symbol "=") Expression ")" body option("else" option("|" Symbol "|") body)
TryExpression(body) = "try" "(" Expression ")" option("|" option("*") Symbol "|") body option("else" option("|" Symbol "|") BlockExpression(body))
*/
static AstNode *ast_parse_try_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *try_token = &pc->tokens->at(*token_index);
@@ -656,38 +656,25 @@ static AstNode *ast_parse_try_expr(ParseContext *pc, size_t *token_index, bool m
AstNode *node = ast_create_node(pc, NodeTypeTryExpr, try_token);
ast_eat_token(pc, token_index, TokenIdLParen);
node->data.try_expr.target_node = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
Token *var_token = &pc->tokens->at(*token_index);
bool have_vars;
if (var_token->id == TokenIdKeywordVar) {
node->data.try_expr.var_is_const = false;
Token *open_bar_tok = &pc->tokens->at(*token_index);
if (open_bar_tok->id == TokenIdBinOr) {
*token_index += 1;
have_vars = true;
} else if (var_token->id == TokenIdKeywordConst) {
node->data.try_expr.var_is_const = true;
*token_index += 1;
have_vars = true;
} else {
have_vars = false;
}
if (have_vars) {
Token *star_token = &pc->tokens->at(*token_index);
if (star_token->id == TokenIdStar) {
node->data.try_expr.var_is_ptr = true;
Token *star_tok = &pc->tokens->at(*token_index);
if (star_tok->id == TokenIdStar) {
*token_index += 1;
node->data.try_expr.var_is_ptr = true;
}
Token *var_name_tok = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.try_expr.var_symbol = token_buf(var_name_tok);
ast_eat_token(pc, token_index, TokenIdEq);
ast_eat_token(pc, token_index, TokenIdBinOr);
}
node->data.try_expr.target_node = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
node->data.try_expr.then_node = ast_parse_block_or_expression(pc, token_index, true);
Token *else_token = &pc->tokens->at(*token_index);
@@ -709,6 +696,53 @@ static AstNode *ast_parse_try_expr(ParseContext *pc, size_t *token_index, bool m
return node;
}
/*
TestExpression(body) = "test" "(" Expression ")" option("|" option("*") Symbol "|") body option("else" BlockExpression(body))
*/
static AstNode *ast_parse_test_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *test_token = &pc->tokens->at(*token_index);
if (test_token->id == TokenIdKeywordTest) {
*token_index += 1;
} else if (mandatory) {
ast_expect_token(pc, test_token, TokenIdKeywordTest);
zig_unreachable();
} else {
return nullptr;
}
AstNode *node = ast_create_node(pc, NodeTypeTestExpr, test_token);
ast_eat_token(pc, token_index, TokenIdLParen);
node->data.test_expr.target_node = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
Token *open_bar_tok = &pc->tokens->at(*token_index);
if (open_bar_tok->id == TokenIdBinOr) {
*token_index += 1;
Token *star_tok = &pc->tokens->at(*token_index);
if (star_tok->id == TokenIdStar) {
*token_index += 1;
node->data.test_expr.var_is_ptr = true;
}
Token *var_name_tok = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.test_expr.var_symbol = token_buf(var_name_tok);
ast_eat_token(pc, token_index, TokenIdBinOr);
}
node->data.test_expr.then_node = ast_parse_block_or_expression(pc, token_index, true);
Token *else_token = &pc->tokens->at(*token_index);
if (else_token->id == TokenIdKeywordElse) {
*token_index += 1;
node->data.test_expr.else_node = ast_parse_block_expr_or_expression(pc, token_index, true);
}
return node;
}
/*
PrimaryExpression = Number | String | CharLiteral | KeywordLiteral | GroupedExpression | GotoExpression | BlockExpression(BlockOrExpression) | Symbol | ("@" Symbol FnCallExpression) | ArrayType | (option("extern") FnProto) | AsmExpression | ("error" "." Symbol) | ContainerDecl
KeywordLiteral = "true" | "false" | "null" | "break" | "continue" | "undefined" | "error" | "this" | "unreachable"
@@ -1405,9 +1439,7 @@ static AstNode *ast_parse_bool_and_expr(ParseContext *pc, size_t *token_index, b
}
/*
IfExpression(body) = IfVarExpression(body) | IfBoolExpression(body)
IfBoolExpression(body) = "if" "(" Expression ")" body option("else" body)
IfVarExpression(body) = "if" "(" ("const" | "var") option("*") Symbol option(":" TypeExpr) "?=" Expression ")" body Option("else" body)
IfExpression(body) = "if" "(" Expression ")" body option("else" BlockExpression(body))
*/
static AstNode *ast_parse_if_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *if_token = &pc->tokens->at(*token_index);
@@ -1423,63 +1455,18 @@ static AstNode *ast_parse_if_expr(ParseContext *pc, size_t *token_index, bool ma
ast_eat_token(pc, token_index, TokenIdLParen);
Token *token = &pc->tokens->at(*token_index);
if (token->id == TokenIdKeywordConst || token->id == TokenIdKeywordVar) {
AstNode *node = ast_create_node(pc, NodeTypeIfVarExpr, if_token);
node->data.if_var_expr.var_decl.is_const = (token->id == TokenIdKeywordConst);
AstNode *node = ast_create_node(pc, NodeTypeIfBoolExpr, if_token);
node->data.if_bool_expr.condition = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
node->data.if_bool_expr.then_block = ast_parse_block_or_expression(pc, token_index, true);
Token *else_token = &pc->tokens->at(*token_index);
if (else_token->id == TokenIdKeywordElse) {
*token_index += 1;
Token *star_or_symbol = &pc->tokens->at(*token_index);
if (star_or_symbol->id == TokenIdStar) {
*token_index += 1;
node->data.if_var_expr.var_is_ptr = true;
Token *name_token = ast_eat_token(pc, token_index, TokenIdSymbol);
node->data.if_var_expr.var_decl.symbol = token_buf(name_token);
} else if (star_or_symbol->id == TokenIdSymbol) {
*token_index += 1;
node->data.if_var_expr.var_decl.symbol = token_buf(star_or_symbol);
} else {
ast_invalid_token_error(pc, star_or_symbol);
}
Token *eq_or_colon = &pc->tokens->at(*token_index);
if (eq_or_colon->id == TokenIdMaybeAssign) {
*token_index += 1;
node->data.if_var_expr.var_decl.expr = ast_parse_expression(pc, token_index, true);
} else if (eq_or_colon->id == TokenIdColon) {
*token_index += 1;
node->data.if_var_expr.var_decl.type = ast_parse_type_expr(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdMaybeAssign);
node->data.if_var_expr.var_decl.expr = ast_parse_expression(pc, token_index, true);
} else {
ast_invalid_token_error(pc, eq_or_colon);
}
ast_eat_token(pc, token_index, TokenIdRParen);
node->data.if_var_expr.then_block = ast_parse_block_or_expression(pc, token_index, true);
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_expr_or_expression(pc, token_index, true);
}
return node;
} else {
AstNode *node = ast_create_node(pc, NodeTypeIfBoolExpr, if_token);
node->data.if_bool_expr.condition = ast_parse_expression(pc, token_index, true);
ast_eat_token(pc, token_index, TokenIdRParen);
node->data.if_bool_expr.then_block = ast_parse_block_or_expression(pc, token_index, true);
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_expr_or_expression(pc, token_index, true);
}
return node;
node->data.if_bool_expr.else_node = ast_parse_block_expr_or_expression(pc, token_index, true);
}
return node;
}
/*
@@ -1862,7 +1849,7 @@ static AstNode *ast_parse_switch_expr(ParseContext *pc, size_t *token_index, boo
}
/*
BlockExpression(body) = Block | IfExpression(body) | TryExpression(body) | WhileExpression(body) | ForExpression(body) | SwitchExpression | CompTimeExpression(body)
BlockExpression(body) = Block | IfExpression(body) | TryExpression(body) | TestExpression(body) | WhileExpression(body) | ForExpression(body) | SwitchExpression | CompTimeExpression(body)
*/
static AstNode *ast_parse_block_expr(ParseContext *pc, size_t *token_index, bool mandatory) {
Token *token = &pc->tokens->at(*token_index);
@@ -1895,6 +1882,10 @@ static AstNode *ast_parse_block_expr(ParseContext *pc, size_t *token_index, bool
if (try_node)
return try_node;
AstNode *test_node = ast_parse_test_expr(pc, token_index, false);
if (test_node)
return test_node;
if (mandatory)
ast_invalid_token_error(pc, token);
@@ -2079,14 +2070,14 @@ static bool statement_terminates_without_semicolon(AstNode *node) {
if (node->data.if_bool_expr.else_node)
return statement_terminates_without_semicolon(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 statement_terminates_without_semicolon(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 statement_terminates_without_semicolon(node->data.try_expr.else_node);
return node->data.try_expr.then_node->type == NodeTypeBlock;
case NodeTypeTestExpr:
if (node->data.test_expr.else_node)
return statement_terminates_without_semicolon(node->data.test_expr.else_node);
return node->data.test_expr.then_node->type == NodeTypeBlock;
case NodeTypeWhileExpr:
return node->data.while_expr.body->type == NodeTypeBlock;
case NodeTypeForExpr:
@@ -2667,17 +2658,16 @@ void ast_visit_node_children(AstNode *node, void (*visit)(AstNode **, void *cont
visit_field(&node->data.if_bool_expr.then_block, visit, context);
visit_field(&node->data.if_bool_expr.else_node, visit, context);
break;
case NodeTypeIfVarExpr:
visit_field(&node->data.if_var_expr.var_decl.type, visit, context);
visit_field(&node->data.if_var_expr.var_decl.expr, visit, context);
visit_field(&node->data.if_var_expr.then_block, visit, context);
visit_field(&node->data.if_var_expr.else_node, visit, context);
break;
case NodeTypeTryExpr:
visit_field(&node->data.try_expr.target_node, visit, context);
visit_field(&node->data.try_expr.then_node, visit, context);
visit_field(&node->data.try_expr.else_node, visit, context);
break;
case NodeTypeTestExpr:
visit_field(&node->data.test_expr.target_node, visit, context);
visit_field(&node->data.test_expr.then_node, visit, context);
visit_field(&node->data.test_expr.else_node, visit, context);
break;
case NodeTypeWhileExpr:
visit_field(&node->data.while_expr.condition, visit, context);
visit_field(&node->data.while_expr.body, visit, context);