fn tokenize(mut input: &str) -> crate::Result<Self> {
        let mut tokens = vec![];
        let mut loc = Location::default();
        while !input.is_empty() {
            let old_input = input;
            let mut chars = input.chars();
            let kind = match chars.next().unwrap() {
                '"' => {
                    let mut buf = Vec::new();
                    loop {
                        match chars.next() {
                            None => bail!("unclosed double quote"),
                            // When we read a double quote inside a double quote
                            // we need to lookahead to determine whether it's an
                            // escape sequence or a closing delimiter.
                            Some('"') => match lookahead(&chars) {
                                Some('"') => {
                                    if buf.is_empty() {
                                        break;
                                    }
                                    let _ = chars.next();
                                    buf.push('"');
                                    buf.push('"');
                                }
                                Some(_) | None => break,
                            },
                            Some(c) if c.is_ascii() => buf.push(c),
                            _ => bail!("Invalid ado.net token"),
                        }
                    }
                    TokenKind::Escaped(buf)
                }
                '\'' => {
                    let mut buf = Vec::new();
                    loop {
                        match chars.next() {
                            None => bail!("unclosed single quote"),
                            // When we read a single quote inside a single quote
                            // we need to lookahead to determine whether it's an
                            // escape sequence or a closing delimiter.
                            Some('\'') => match lookahead(&chars) {
                                Some('\'') => {
                                    if buf.is_empty() {
                                        break;
                                    }
                                    let _ = chars.next();
                                    buf.push('\'');
                                    buf.push('\'');
                                }
                                Some(_) | None => break,
                            },
                            Some(c) if c.is_ascii() => buf.push(c),
                            Some(c) => bail!("Invalid ado.net token `{}`", c),
                        }
                    }
                    TokenKind::Escaped(buf)
                }
                '{' => {
                    let mut buf = Vec::new();
                    // Read alphanumeric ASCII including whitespace until we find a closing curly.
                    loop {
                        match chars.next() {
                            None => bail!("unclosed escape literal"),
                            Some('}') => break,
                            Some(c) if c.is_ascii() => buf.push(c),
                            Some(c) => bail!("Invalid ado.net token `{}`", c),
                        }
                    }
                    TokenKind::Escaped(buf)
                }
                ';' => TokenKind::Semi,
                '=' => TokenKind::Eq,
                '\n' => TokenKind::Newline,
                ' ' => TokenKind::Whitespace,
                char if char.is_ascii() => TokenKind::Atom(char),
                char => bail!("Invalid character found: {}", char),
            };
            tokens.push(Token::new(kind, loc));
            input = chars.as_str();

            let consumed = old_input.len() - input.len();
            loc.advance(&old_input[..consumed]);
        }
        tokens.reverse();
        Ok(Self { tokens })
    }
/// Parse a string into a sequence of tokens.
Parse a string into a sequence of tokens.
Parse a string into a sequence of tokens .
fn tokenize(mut input: &str) -> crate::Result<Self> {
        let mut tokens = vec![];
        let mut loc = Location::default();
        while !input.is_empty() {
            let old_input = input;
            let mut chars = input.chars();
            let kind = match chars.next().unwrap() {
                '"' => {
                    let mut buf = Vec::new();
                    loop {
                        match chars.next() {
                            None => bail!("unclosed double quote"),
                            // When we read a double quote inside a double quote
                            // we need to lookahead to determine whether it's an
                            // escape sequence or a closing delimiter.
                            Some('"') => match lookahead(&chars) {
                                Some('"') => {
                                    if buf.is_empty() {
                                        break;
                                    }
                                    let _ = chars.next();
                                    buf.push('"');
                                    buf.push('"');
                                }
                                Some(_) | None => break,
                            },
                            Some(c) if c.is_ascii() => buf.push(c),
                            _ => bail!("Invalid ado.net token"),
                        }
                    }
                    TokenKind::Escaped(buf)
                }
                '\'' => {
                    let mut buf = Vec::new();
                    loop {
                        match chars.next() {
                            None => bail!("unclosed single quote"),
                            // When we read a single quote inside a single quote
                            // we need to lookahead to determine whether it's an
                            // escape sequence or a closing delimiter.
                            Some('\'') => match lookahead(&chars) {
                                Some('\'') => {
                                    if buf.is_empty() {
                                        break;
                                    }
                                    let _ = chars.next();
                                    buf.push('\'');
                                    buf.push('\'');
                                }
                                Some(_) | None => break,
                            },
                            Some(c) if c.is_ascii() => buf.push(c),
                            Some(c) => bail!("Invalid ado.net token `{}`", c),
                        }
                    }
                    TokenKind::Escaped(buf)
                }
                '{' => {
                    let mut buf = Vec::new();
                    // Read alphanumeric ASCII including whitespace until we find a closing curly.
                    loop {
                        match chars.next() {
                            None => bail!("unclosed escape literal"),
                            Some('}') => break,
                            Some(c) if c.is_ascii() => buf.push(c),
                            Some(c) => bail!("Invalid ado.net token `{}`", c),
                        }
                    }
                    TokenKind::Escaped(buf)
                }
                ';' => TokenKind::Semi,
                '=' => TokenKind::Eq,
                '\n' => TokenKind::Newline,
                ' ' => TokenKind::Whitespace,
                char if char.is_ascii() => TokenKind::Atom(char),
                char => bail!("Invalid character found: {}", char),
            };
            tokens.push(Token::new(kind, loc));
            input = chars.as_str();
            let consumed = old_input.len() - input.len();
            loc.advance(&old_input[..consumed]);
        }
        tokens.reverse();
        Ok(Self { tokens })
    }
fn tokenize ( mut input : & str ) -> crate :: Result < Self > { let mut tokens = vec ! [ ] ; let mut loc = Location :: default ( ) ; while ! input . is_empty ( ) { let old_input = input ; let mut chars = input . chars ( ) ; let kind = match chars . next ( ) . unwrap ( ) { '"' => { let mut buf = Vec :: new ( ) ; loop { match chars . next ( ) { None => bail ! ( " " ) , // When we read a double quote inside a double quote // we need to lookahead to determine whether it's an // escape sequence or a closing delimiter. Some ( '"' ) => match lookahead ( & chars ) { Some ( '"' ) => { if buf . is_empty ( ) { break ; } let _ = chars . next ( ) ; buf . push ( '"' ) ; buf . push ( '"' ) ; } Some ( _ ) | None => break , } , Some ( c ) if c . is_ascii ( ) => buf . push ( c ) , _ => bail ! ( " " ) , } } TokenKind :: Escaped ( buf ) } '\'' => { let mut buf = Vec :: new ( ) ; loop { match chars . next ( ) { None => bail ! ( " " ) , // When we read a single quote inside a single quote // we need to lookahead to determine whether it's an // escape sequence or a closing delimiter. Some ( '\'' ) => match lookahead ( & chars ) { Some ( '\'' ) => { if buf . is_empty ( ) { break ; } let _ = chars . next ( ) ; buf . push ( '\'' ) ; buf . push ( '\'' ) ; } Some ( _ ) | None => break , } , Some ( c ) if c . is_ascii ( ) => buf . push ( c ) , Some ( c ) => bail ! ( " " c ) , } } TokenKind :: Escaped ( buf ) } '{' => { let mut buf = Vec :: new ( ) ; // Read alphanumeric ASCII including whitespace until we find a closing curly. loop { match chars . next ( ) { None => bail ! ( " " ) , Some ( '}' ) => break , Some ( c ) if c . is_ascii ( ) => buf . push ( c ) , Some ( c ) => bail ! ( " " c ) , } } TokenKind :: Escaped ( buf ) } ';' => TokenKind :: Semi , '=' => TokenKind :: Eq , '\n' => TokenKind :: Newline , ' ' => TokenKind :: Whitespace , char if char . is_ascii ( ) => TokenKind :: Atom ( char ) , char => bail ! ( " " char ) , } ; tokens . push ( Token :: new ( kind , loc ) ) ; input = chars . as_str ( ) ; let consumed = old_input . len ( ) - input . len ( ) ; loc . advance ( & old_input [ .. consumed ] ) ; } tokens . reverse ( ) ; Ok ( Self { tokens } ) }
Parse a string into a sequence of tokens.
Parse a string into a sequence of tokens .
input
&str
input
&str