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LibJS/Parser: Implement the parsing of unary/prefixed update expressions

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0xtechnobabble 2020-03-14 20:45:51 +02:00 • committed by Andreas Kling
parent db64f364f0
commit 2e90a7eb2d
2 changed files with 39 additions and 1 deletions
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38
Libraries/LibJS/Parser.cpp
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@ -233,6 +233,29 @@ NonnullOwnPtr<Expression> Parser::parse_primary_expression()
}
}
NonnullOwnPtr<Expression> Parser::parse_unary_prefixed_expression()
{
switch (m_current_token.type()) {
case TokenType::PlusPlus:
consume();
return make<UpdateExpression>(UpdateOp::Increment, parse_primary_expression(), true);
case TokenType::MinusMinus:
consume();
return make<UpdateExpression>(UpdateOp::Decrement, parse_primary_expression(), true);
case TokenType::ExclamationMark:
consume();
return make<UnaryExpression>(UnaryOp::Not, parse_primary_expression());
case TokenType::Tilde:
consume();
return make<UnaryExpression>(UnaryOp::BitwiseNot, parse_primary_expression());
default:
m_has_errors = true;
expected("primary expression (missing switch case)");
consume();
return make<ErrorExpression>();
}
}
NonnullOwnPtr<ObjectExpression> Parser::parse_object_expression()
{
// FIXME: Parse actual object expression
@ -243,6 +266,9 @@ NonnullOwnPtr<ObjectExpression> Parser::parse_object_expression()
NonnullOwnPtr<Expression> Parser::parse_expression(int min_precedence, Associativity associativity)
{
if (match_unary_prefixed_expression())
return parse_unary_prefixed_expression();
auto expression = parse_primary_expression();
while (match_secondary_expression()) {
int new_precedence = operator_precedence(m_current_token.type());
@ -477,7 +503,17 @@ bool Parser::match_expression() const
|| type == TokenType::New
|| type == TokenType::CurlyOpen
|| type == TokenType::BracketOpen
|| type == TokenType::ParenOpen;
|| type == TokenType::ParenOpen
|| match_unary_prefixed_expression();
}
bool Parser::match_unary_prefixed_expression() const
{
auto type = m_current_token.type();
return type == TokenType::PlusPlus
|| type == TokenType::MinusMinus
|| type == TokenType::ExclamationMark
|| type == TokenType::Tilde;
}
bool Parser::match_secondary_expression() const

2
Libraries/LibJS/Parser.h
View file

@ -52,6 +52,7 @@ public:
NonnullOwnPtr<Expression> parse_expression(int min_precedence, Associativity associate = Associativity::Right);
NonnullOwnPtr<Expression> parse_primary_expression();
NonnullOwnPtr<Expression> parse_unary_prefixed_expression();
NonnullOwnPtr<ObjectExpression> parse_object_expression();
NonnullOwnPtr<Expression> parse_secondary_expression(NonnullOwnPtr<Expression>, int min_precedence, Associativity associate = Associativity::Right);
NonnullOwnPtr<CallExpression> parse_call_expression(NonnullOwnPtr<Expression>);
@ -62,6 +63,7 @@ private:
int operator_precedence(TokenType) const;
Associativity operator_associativity(TokenType) const;
bool match_expression() const;
bool match_unary_prefixed_expression() const;
bool match_secondary_expression() const;
bool match_statement() const;
bool match(TokenType type) const;