fn tokenize_quoted_string()

in src/tokenizer.rs [1982:2086]

• 87 lines of code
• 18 McCabe index (conditional complexity)

    fn tokenize_quoted_string(
        &self,
        chars: &mut State,
        settings: TokenizeQuotedStringSettings,
    ) -> Result<String, TokenizerError> {
        let mut s = String::new();
        let error_loc = chars.location();

        // Consume any opening quotes.
        for _ in 0..settings.num_opening_quotes_to_consume {
            if Some(settings.quote_style) != chars.next() {
                return self.tokenizer_error(error_loc, "invalid string literal opening");
            }
        }

        let mut num_consecutive_quotes = 0;
        while let Some(&ch) = chars.peek() {
            let pending_final_quote = match settings.num_quote_chars {
                NumStringQuoteChars::One => Some(NumStringQuoteChars::One),
                n @ NumStringQuoteChars::Many(count)
                    if num_consecutive_quotes + 1 == count.get() =>
                {
                    Some(n)
                }
                NumStringQuoteChars::Many(_) => None,
            };

            match ch {
                char if char == settings.quote_style && pending_final_quote.is_some() => {
                    chars.next(); // consume

                    if let Some(NumStringQuoteChars::Many(count)) = pending_final_quote {
                        // For an initial string like `"""abc"""`, at this point we have
                        // `abc""` in the buffer and have now matched the final `"`.
                        // However, the string to return is simply `abc`, so we strip off
                        // the trailing quotes before returning.
                        let mut buf = s.chars();
                        for _ in 1..count.get() {
                            buf.next_back();
                        }
                        return Ok(buf.as_str().to_string());
                    } else if chars
                        .peek()
                        .map(|c| *c == settings.quote_style)
                        .unwrap_or(false)
                    {
                        s.push(ch);
                        if !self.unescape {
                            // In no-escape mode, the given query has to be saved completely
                            s.push(ch);
                        }
                        chars.next();
                    } else {
                        return Ok(s);
                    }
                }
                '\\' if settings.backslash_escape => {
                    // consume backslash
                    chars.next();

                    num_consecutive_quotes = 0;

                    if let Some(next) = chars.peek() {
                        if !self.unescape
                            || (self.dialect.ignores_wildcard_escapes()
                                && (*next == '%' || *next == '_'))
                        {
                            // In no-escape mode, the given query has to be saved completely
                            // including backslashes. Similarly, with ignore_like_wildcard_escapes,
                            // the backslash is not stripped.
                            s.push(ch);
                            s.push(*next);
                            chars.next(); // consume next
                        } else {
                            let n = match next {
                                '0' => '\0',
                                'a' => '\u{7}',
                                'b' => '\u{8}',
                                'f' => '\u{c}',
                                'n' => '\n',
                                'r' => '\r',
                                't' => '\t',
                                'Z' => '\u{1a}',
                                _ => *next,
                            };
                            s.push(n);
                            chars.next(); // consume next
                        }
                    }
                }
                ch => {
                    chars.next(); // consume ch

                    if ch == settings.quote_style {
                        num_consecutive_quotes += 1;
                    } else {
                        num_consecutive_quotes = 0;
                    }

                    s.push(ch);
                }
            }
        }
        self.tokenizer_error(error_loc, "Unterminated string literal")
    }