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LibJS: Add numeric literal parsing for different bases and exponents

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This commit is contained in:
Stephan Unverwerth 2020-04-05 14:20:58 +02:00 • committed by Andreas Kling
parent b82a2239c6
commit 500f6d9e3a
4 changed files with 107 additions and 5 deletions
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71
Libraries/LibJS/Lexer.cpp
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@ -156,6 +156,16 @@ void Lexer::consume()
m_current_char = m_source[m_position++];
}
void Lexer::consume_exponent()
{
consume();
if (m_current_char == '-' || m_current_char == '+')
consume();
while (isdigit(m_current_char)) {
consume();
}
}
bool Lexer::is_eof() const
{
return m_current_char == EOF;
@ -186,6 +196,11 @@ bool Lexer::is_block_comment_end() const
return m_current_char == '*' && m_position < m_source.length() && m_source[m_position] == '/';
}
bool Lexer::is_numeric_literal_start() const
{
return isdigit(m_current_char) || (m_current_char == '.' && m_position < m_source.length() && isdigit(m_source[m_position]));
}
void Lexer::syntax_error(const char* msg)
{
m_has_errors = true;
@ -235,10 +250,59 @@ Token Lexer::next()
} else {
token_type = it->value;
}
} else if (isdigit(m_current_char)) {
consume();
while (m_current_char == '.' || isdigit(m_current_char)) {
} else if (is_numeric_literal_start()) {
if (m_current_char == '0') {
consume();
if (m_current_char == '.') {
// decimal
consume();
while (isdigit(m_current_char)) {
consume();
}
if (m_current_char == 'e' || m_current_char == 'E') {
consume_exponent();
}
} else if (m_current_char == 'e' || m_current_char == 'E') {
consume_exponent();
} else if (m_current_char == 'o' || m_current_char == 'O') {
// octal
consume();
while (m_current_char >= '0' && m_current_char <= '7') {
consume();
}
} else if (m_current_char == 'b' || m_current_char == 'B') {
// binary
consume();
while (m_current_char == '0' || m_current_char == '1') {
consume();
}
} else if (m_current_char == 'x' || m_current_char == 'X') {
// hexadecimal
consume();
while (isxdigit(m_current_char)) {
consume();
}
} else if (isdigit(m_current_char)) {
// octal without 'O' prefix. Forbidden in 'strict mode'
// FIXME: We need to make sure this produces a syntax error when in strict mode
do {
consume();
} while (isdigit(m_current_char));
}
} else {
// 1...9 or period
while (isdigit(m_current_char)) {
consume();
}
if (m_current_char == '.') {
consume();
while (isdigit(m_current_char)) {
consume();
}
}
if (m_current_char == 'e' || m_current_char == 'E') {
consume_exponent();
}
}
token_type = TokenType::NumericLiteral;
} else if (m_current_char == '"' || m_current_char == '\'') {
@ -330,5 +394,4 @@ Token Lexer::next()
return m_current_token;
}
}