Lex a string literal.
(&mut self, quote: char)
| 916 | |
| 917 | /// Lex a string literal. |
| 918 | fn lex_string(&mut self, quote: char) -> TokenKind { |
| 919 | #[cfg(debug_assertions)] |
| 920 | debug_assert_eq!(self.cursor.previous(), quote); |
| 921 | |
| 922 | if quote == '"' { |
| 923 | self.current_flags |= TokenFlags::DOUBLE_QUOTES; |
| 924 | } |
| 925 | |
| 926 | // If the next two characters are also the quote character, then we have a triple-quoted |
| 927 | // string; consume those two characters and ensure that we require a triple-quote to close |
| 928 | if self.cursor.eat_char2(quote, quote) { |
| 929 | self.current_flags |= TokenFlags::TRIPLE_QUOTED_STRING; |
| 930 | } |
| 931 | |
| 932 | let quote_byte = u8::try_from(quote).expect("char that fits in u8"); |
| 933 | if self.current_flags.is_triple_quoted() { |
| 934 | // For triple-quoted strings, scan until we find the closing quote (ignoring escaped |
| 935 | // quotes) or the end of the file. |
| 936 | loop { |
| 937 | let Some(index) = memchr::memchr(quote_byte, self.cursor.rest().as_bytes()) else { |
| 938 | self.cursor.skip_to_end(); |
| 939 | |
| 940 | self.current_flags |= TokenFlags::UNCLOSED_STRING; |
| 941 | self.push_error(LexicalError::new( |
| 942 | LexicalErrorType::UnclosedStringError, |
| 943 | self.token_range(), |
| 944 | )); |
| 945 | break; |
| 946 | }; |
| 947 | |
| 948 | // Rare case: if there are an odd number of backslashes before the quote, then |
| 949 | // the quote is escaped and we should continue scanning. |
| 950 | let num_backslashes = self.cursor.rest().as_bytes()[..index] |
| 951 | .iter() |
| 952 | .rev() |
| 953 | .take_while(|&&c| c == b'\\') |
| 954 | .count(); |
| 955 | |
| 956 | // Advance the cursor past the quote and continue scanning. |
| 957 | self.cursor.skip_bytes(index + 1); |
| 958 | |
| 959 | // If the character is escaped, continue scanning. |
| 960 | if num_backslashes % 2 == 1 { |
| 961 | continue; |
| 962 | } |
| 963 | |
| 964 | // Otherwise, if it's followed by two more quotes, then we're done. |
| 965 | if self.cursor.eat_char2(quote, quote) { |
| 966 | break; |
| 967 | } |
| 968 | } |
| 969 | } else { |
| 970 | // For non-triple-quoted strings, scan until we find the closing quote, but end early |
| 971 | // if we encounter a newline or the end of the file. |
| 972 | loop { |
| 973 | let Some(index) = |
| 974 | memchr::memchr3(quote_byte, b'\r', b'\n', self.cursor.rest().as_bytes()) |
| 975 | else { |
no test coverage detected