Trait parser_combinators::combinator::ParserExt [−] [src]

pub trait ParserExt: Parser + Sized {
    fn with<P2>(self, p: P2) -> With<Self, P2>
    where
        P2: Parser<Input = Self::Input>,
    { ... }
    fn skip<P2>(self, p: P2) -> Skip<Self, P2>
    where
        P2: Parser<Input = Self::Input>,
    { ... }
    fn and<P2>(self, p: P2) -> And<Self, P2>
    where
        P2: Parser<Input = Self::Input>,
    { ... }
    fn or<P2>(self, p: P2) -> Or<Self, P2>
    where
        P2: Parser<Input = Self::Input>,
    { ... }
    fn then<N, F>(self, f: F) -> Then<Self, F>
    where
        F: FnMut(Self::Output) -> N,
        N: Parser<Input = Self::Input>,
    { ... }
    fn map<F, B>(self, f: F) -> Map<Self, F>
    where
        F: FnMut(Self::Output) -> B,
    { ... }
    fn message<S>(self, msg: S) -> Message<Self>
    where
        S: Into<Info<<Self::Input as Stream>::Item>>,
    { ... }
    fn expected<S>(self, msg: S) -> Expected<Self>
    where
        S: Into<Info<<Self::Input as Stream>::Item>>,
    { ... }
    fn and_then<F, O, E>(self, f: F) -> AndThen<Self, F>
    where
        F: FnMut(Self::Output) -> Result<O, E>,
        E: Into<Error<<Self::Input as Stream>::Item>>,
    { ... }
    fn iter(self, input: State<Self::Input>) -> Iter<Self> { ... }
}

Extension trait which provides functions that are more conveniently used through method calls

Provided Methods

Discards the value of the self parser and returns the value of p Fails if any of the parsers fails

 let result = digit()
     .with(token('i'))
     .parse("9i")
     .map(|x| x.0);
 assert_eq!(result, Ok('i'));

Discards the value of the p parser and returns the value of self Fails if any of the parsers fails

 let result = digit()
     .skip(token('i'))
     .parse("9i")
     .map(|x| x.0);
 assert_eq!(result, Ok('9'));

Parses with self followed by p Succeds if both parsers succed, otherwise fails Returns a tuple with both values on success

 let result = digit()
     .and(token('i'))
     .parse("9i")
     .map(|x| x.0);
 assert_eq!(result, Ok(('9', 'i')));

Tries to parse using self and if it fails returns the result of parsing p

 let result = digit().map(|_| "")
     .or(string("let"))
     .parse("let")
     .map(|x| x.0);
 assert_eq!(result, Ok("let"));

Parses using self and then passes the value to f which returns a parser used to parse the rest of the input

 let result = digit()
     .then(|d| parser(move |input| {
         if d == '9' {
             Ok((9, Consumed::Empty(input)))
         }
         else {
             let err = ParseError::new(input.position, Error::Message("Not a nine".into()));
             Err((Consumed::Empty(err)))
         }
     }))
     .parse("9");
 assert_eq!(result, Ok((9, "")));

Uses f to map over the parsed value

 let result = digit()
     .map(|c| c == '9')
     .parse("9")
     .map(|x| x.0);
 assert_eq!(result, Ok(true));

Parses with self and if it fails, adds the message msg to the error

 let result = token('9')
     .message("Not a nine")
     .parse("8");
 assert!(result.is_err());
 assert!(result.unwrap_err().errors.iter()
     .find(|e| **e == Error::Message("Not a nine".into())).is_some());

Parses with self and if it fails without consuming any input any expected errors are replaced by msg. msg is then used in error messages as "Expected msg".

 let result = token('9')
     .expected("9")
     .parse("8");
 assert!(result.is_err());
 assert!(result.unwrap_err().errors.iter()
     .find(|e| **e == Error::Expected("9".into())).is_some());

Parses with self and applies f on the result if self parses successfully f may optionally fail with an error which is automatically converted to a ParseError

 let mut parser = many1(digit())
     .and_then(|s: String| s.parse::<i32>());
 let result = parser.parse("1234");
 assert_eq!(result, Ok((1234, "")));
 let err = parser.parse("abc");
 assert!(err.is_err());

Creates an iterator from a parser and a state. Can be used as an alternative to many when collecting directly into a FromIterator type is not desirable

 let mut buffer = String::new();
 let number = parser(|input| {
     buffer.clear();
     let mut iter = digit().iter(input);
     buffer.extend(&mut iter);
     let i = buffer.parse::<i32>().unwrap();
     iter.into_result(i)
 });
 let result = sep_by(number, char(','))
     .parse("123,45,6");
 assert_eq!(result, Ok((vec![123, 45, 6], "")));

Implementors