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use super::{Lexer, StringPart, Token};
impl Lexer {
pub(in crate::lexer) fn read_string(&mut self) -> Token {
self.advance(); // Skip opening quote
let mut parts = Vec::new();
let mut current_literal = String::new();
let mut has_interpolation = false;
while let Some(ch) = self.current_char {
if ch == '"' {
self.advance(); // Skip closing quote
break;
} else if ch == '\\' {
self.advance();
if let Some(escaped) = self.current_char {
let unescaped = match escaped {
'n' => '\n',
't' => '\t',
'r' => '\r',
'\\' => '\\',
'"' => '"',
_ => escaped,
};
current_literal.push(unescaped);
self.advance();
}
} else if ch == '$' && self.peek(1) == Some('$') {
// Escaped dollar: $$ → literal $
current_literal.push('$');
self.advance();
self.advance();
} else if ch == '$' && self.peek(1) == Some('{') {
// Found interpolation: ${expr}
has_interpolation = true;
// Save current literal part
if !current_literal.is_empty() {
parts.push(StringPart::Literal(current_literal.clone()));
current_literal.clear();
}
// Skip ${
self.advance();
self.advance();
// Read expression until }
let mut expr = String::new();
let mut brace_depth = 1;
while let Some(expr_ch) = self.current_char {
if expr_ch == '{' {
brace_depth += 1;
expr.push(expr_ch);
self.advance();
} else if expr_ch == '}' {
brace_depth -= 1;
if brace_depth == 0 {
self.advance(); // Skip closing }
break;
}
expr.push(expr_ch);
self.advance();
} else {
expr.push(expr_ch);
self.advance();
}
}
parts.push(StringPart::Expression(expr));
} else {
current_literal.push(ch);
self.advance();
}
}
// Add final literal part if any
if !current_literal.is_empty() || parts.is_empty() {
parts.push(StringPart::Literal(current_literal));
}
if has_interpolation {
Token::InterpolatedString(parts)
} else {
// Simple string with no interpolation
if let Some(StringPart::Literal(s)) = parts.into_iter().next() {
Token::StringLiteral(s)
} else {
Token::StringLiteral(String::new())
}
}
}
pub(in crate::lexer) fn read_raw_string(&mut self) -> Token {
// Skip r#"
self.advance(); // r
self.advance(); // #
self.advance(); // "
let mut content = String::new();
// Read until we find "#
while let Some(ch) = self.current_char {
if ch == '"' && self.peek(1) == Some('#') {
// Found closing "#
self.advance(); // "
self.advance(); // #
break;
} else {
content.push(ch);
self.advance();
}
}
Token::StringLiteral(content)
}
pub(in crate::lexer) fn read_char(&mut self) -> Token {
self.advance(); // Skip opening quote
let ch = if let Some(c) = self.current_char {
if c == '\\' {
// Handle escape sequences
self.advance();
if let Some(escaped) = self.current_char {
let unescaped = match escaped {
'n' => '\n',
't' => '\t',
'r' => '\r',
'\\' => '\\',
'\'' => '\'',
'0' => '\0',
_ => escaped,
};
self.advance();
unescaped
} else {
'\0'
}
} else {
let character = c;
self.advance();
character
}
} else {
'\0'
};
// Skip closing quote
if self.current_char == Some('\'') {
self.advance();
}
Token::CharLiteral(ch)
}
}