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LibJS: Add using declaration support in for and for of loops

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The using declarations have kind of special behavior in for loops so
this is seperated.
This commit is contained in:
davidot 2022-12-23 01:45:29 +01:00 • committed by Linus Groh
parent 541637e15a
commit bff038411a
6 changed files with 447 additions and 77 deletions
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82
Userland/Libraries/LibJS/Parser.cpp
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@ -3573,7 +3573,38 @@ NonnullRefPtr<Statement> Parser::parse_for_statement()
RefPtr<ASTNode> init;
if (!match(TokenType::Semicolon)) {
if (match_variable_declaration()) {
auto match_for_using_declaration = [&] {
if (!match(TokenType::Identifier) || m_state.current_token.original_value() != "using"sv)
return false;
auto lookahead = next_token();
if (lookahead.trivia_contains_line_terminator())
return false;
if (lookahead.original_value() == "of"sv)
return false;
return token_is_identifier(lookahead);
};
if (match_for_using_declaration()) {
auto declaration = parse_using_declaration(IsForLoopVariableDeclaration::Yes);
if (match_of(m_state.current_token)) {
if (declaration->declarations().size() != 1)
syntax_error("Must have exactly one declaration in for using of");
else if (declaration->declarations().first().init())
syntax_error("Using declaration cannot have initializer");
return parse_for_in_of_statement(move(declaration), is_await_loop);
}
if (match(TokenType::In))
syntax_error("Using declaration not allowed in for-in loop");
init = move(declaration);
} else if (match_variable_declaration()) {
auto declaration = parse_variable_declaration(IsForLoopVariableDeclaration::Yes);
if (declaration->declaration_kind() == DeclarationKind::Var) {
m_state.current_scope_pusher->add_declaration(declaration);
@ -3586,15 +3617,22 @@ NonnullRefPtr<Statement> Parser::parse_for_statement()
});
}
init = move(declaration);
if (match_for_in_of())
return parse_for_in_of_statement(*init, is_await_loop);
if (static_cast<VariableDeclaration&>(*init).declaration_kind() == DeclarationKind::Const) {
for (auto& variable : static_cast<VariableDeclaration&>(*init).declarations()) {
if (match_for_in_of()) {
if (declaration->declarations().size() > 1)
syntax_error("Multiple declarations not allowed in for..in/of");
else if (declaration->declarations().size() < 1)
syntax_error("Need exactly one variable declaration in for..in/of");
return parse_for_in_of_statement(move(declaration), is_await_loop);
}
if (declaration->declaration_kind() == DeclarationKind::Const) {
for (auto const& variable : declaration->declarations()) {
if (!variable.init())
syntax_error("Missing initializer in 'const' variable declaration");
}
}
init = move(declaration);
} else if (match_expression()) {
auto lookahead_token = next_token();
bool starts_with_async_of = match(TokenType::Async) && match_of(lookahead_token);
@ -3641,11 +3679,8 @@ NonnullRefPtr<Statement> Parser::parse_for_in_of_statement(NonnullRefPtr<ASTNode
if (is<VariableDeclaration>(*lhs)) {
auto& declaration = static_cast<VariableDeclaration&>(*lhs);
if (declaration.declarations().size() > 1) {
syntax_error("Multiple declarations not allowed in for..in/of");
} else if (declaration.declarations().size() < 1) {
syntax_error("Need exactly one variable declaration in for..in/of");
} else {
// Syntax errors for wrong amounts of declaration should have already been hit.
if (!declaration.declarations().is_empty()) {
// AnnexB extension B.3.5 Initializers in ForIn Statement Heads, https://tc39.es/ecma262/#sec-initializers-in-forin-statement-heads
auto& variable = declaration.declarations().first();
if (variable.init()) {
@ -3655,7 +3690,7 @@ NonnullRefPtr<Statement> Parser::parse_for_in_of_statement(NonnullRefPtr<ASTNode
has_annexB_for_in_init_extension = true;
}
}
} else if (!lhs->is_identifier() && !is<MemberExpression>(*lhs) && !is<CallExpression>(*lhs)) {
} else if (!lhs->is_identifier() && !is<MemberExpression>(*lhs) && !is<CallExpression>(*lhs) && !is<UsingDeclaration>(*lhs)) {
bool valid = false;
if (is<ObjectExpression>(*lhs) || is<ArrayExpression>(*lhs)) {
auto synthesized_binding_pattern = synthesize_binding_pattern(static_cast<Expression const&>(*lhs));
@ -3915,21 +3950,26 @@ bool Parser::match_variable_declaration() const
bool Parser::match_identifier() const
{
if (m_state.current_token.type() == TokenType::EscapedKeyword) {
if (m_state.current_token.value() == "let"sv)
return token_is_identifier(m_state.current_token);
}
bool Parser::token_is_identifier(Token const& token) const
{
if (token.type() == TokenType::EscapedKeyword) {
if (token.value() == "let"sv)
return !m_state.strict_mode;
if (m_state.current_token.value() == "yield"sv)
if (token.value() == "yield"sv)
return !m_state.strict_mode && !m_state.in_generator_function_context;
if (m_state.current_token.value() == "await"sv)
if (token.value() == "await"sv)
return m_program_type != Program::Type::Module && !m_state.await_expression_is_valid && !m_state.in_class_static_init_block;
return true;
}
return m_state.current_token.type() == TokenType::Identifier
|| m_state.current_token.type() == TokenType::Async
|| (m_state.current_token.type() == TokenType::Let && !m_state.strict_mode)
|| (m_state.current_token.type() == TokenType::Await && m_program_type != Program::Type::Module && !m_state.await_expression_is_valid && !m_state.in_class_static_init_block)
|| (m_state.current_token.type() == TokenType::Yield && !m_state.in_generator_function_context && !m_state.strict_mode); // See note in Parser::parse_identifier().
return token.type() == TokenType::Identifier
|| token.type() == TokenType::Async
|| (token.type() == TokenType::Let && !m_state.strict_mode)
|| (token.type() == TokenType::Await && m_program_type != Program::Type::Module && !m_state.await_expression_is_valid && !m_state.in_class_static_init_block)
|| (token.type() == TokenType::Yield && !m_state.in_generator_function_context && !m_state.strict_mode); // See note in Parser::parse_identifier().
}
bool Parser::match_identifier_name() const