Struct rcombinators::combinators::Transform

pub struct Transform<R, R2, P: Parser<Result = R>, F: Fn(R) -> ParseResult<R2>> { /* fields omitted */ }

Transform applies a function (which may fail) to the result of a parser. Transform only succeeds if the applied function succeeds, too.

Methods

impl<R, R2, P: Parser<Result = R>, F: Fn(R) -> ParseResult<R2>> Transform<R, R2, P, F>

pub fn new(p: P, f: F) -> Transform<R, R2, P, F>

Create a new Transform parser using f.

Trait Implementations

impl<R, R2, P: Parser<Result = R>, F: Fn(R) -> ParseResult<R2>> Parser for Transform<R, R2, P, F>

type Result = R2

fn parse(
    &mut self,
    st: &mut ParseState<impl Iterator<Item = char>>
) -> ParseResult<Self::Result>

parse consumes input from st and returns a result or an error.

fn apply<R2, F: Fn(Self::Result) -> ParseResult<R2>>(
    self,
    f: F
) -> Transform<Self::Result, R2, Self, F> where
    Self: Sized, 

apply transforms the result of this parser using a Transform combinator.

fn then<R2, P: Parser<Result = R2>>(self, p: P) -> Then<Self, P> where
    Self: Sized, 

then attempts to parse input, and if it succeeds, executes parser p, only returning p's result. This is useful for chaining parsers of which the results are not need.