Struct parser_combinators::combinator::Optional

pub struct Optional<P>(_);

Trait Implementations

impl<P: Clone> Clone for Optional<P>

fn clone(&self) -> Optional<P>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<P> Parser for Optional<P> where P: Parser

type Input = P::Input

A type implementing the Stream trait which is the specific type that is parsed.

type Output = Option<P::Output>

The type which is returned when the parsing is successful.

fn parse_state(&mut self, input: State<P::Input>) -> ParseResult<Option<P::Output>, P::Input>

Parses using the state input by calling Stream::uncons one or more times On success returns Ok((value, new_state)) on failure it returns Err(error)

fn parse(&mut self, input: Self::Input) -> Result<(Self::Output, Self::Input), ParseError>

Entrypoint of the parser Takes some input and tries to parse it returning a ParseResult