Struct combine::stream::state::State

pub struct State<I, X> {
    pub input: I,
    pub positioner: X,
}

The State<I> struct maintains the current position in the stream I using the Positioner trait to track the position.

    let result = token(b'9')
        .message("Not a nine")
        .easy_parse(State::new(&b"8"[..]));
    assert_eq!(result, Err(easy::Errors {
        position: 0,
        errors: vec![
            easy::Error::Unexpected(b'8'.into()),
            easy::Error::Expected(b'9'.into()),
            easy::Error::Message("Not a nine".into())
        ]
    }));

Fields

input: I

The input stream used when items are requested

positioner: X

The positioner used to update the current position

Methods

impl<I, X> State<I, X> where
    I: StreamOnce,
    X: Positioner<I::Item>, 

pub fn with_positioner(input: I, positioner: X) -> State<I, X>

Creates a new State<I, X> from an input stream and a positioner.

impl<I> State<I, I::Positioner> where
    I: StreamOnce + DefaultPositioned,
    I::Positioner: Positioner<I::Item>, 

pub fn new(input: I) -> State<I, I::Positioner>

Creates a new State<I, X> from an input stream and its default positioner.

Trait Implementations

impl<I, X, E> Positioned for State<I, X> where
    I: StreamOnce,
    X: Positioner<I::Item>,
    E: StreamError<I::Item, I::Range>,
    I::Error: ParseError<I::Item, I::Range, X::Position, StreamError = E>,
    I::Error: ParseError<I::Item, I::Range, I::Position, StreamError = E>, 

fn position(&self) -> Self::Position

Returns the current position of the stream.

impl<I, X, S> StreamOnce for State<I, X> where
    I: StreamOnce,
    X: Positioner<I::Item>,
    S: StreamError<I::Item, I::Range>,
    I::Error: ParseError<I::Item, I::Range, X::Position, StreamError = S>,
    I::Error: ParseError<I::Item, I::Range, I::Position, StreamError = S>, 

type Item = I::Item

The type of items which is yielded from this stream.

type Range = I::Range

The type of a range of items yielded from this stream. Types which do not a have a way of yielding ranges of items should just use the Self::Item for this type.

type Position = X::Position

Type which represents the position in a stream. Ord is required to allow parsers to determine which of two positions are further ahead.

type Error = I::Error

fn uncons(&mut self) -> Result<I::Item, StreamErrorFor<Self>>

Takes a stream and removes its first item, yielding the item and the rest of the elements. Returns Err if no element could be retrieved.

fn is_partial(&self) -> bool

Returns true if this stream only contains partial input.

impl<I, X, S> ResetStream for State<I, X> where
    I: ResetStream,
    X: Clone + Positioner<I::Item>,
    S: StreamError<I::Item, I::Range>,
    I::Error: ParseError<I::Item, I::Range, X::Position, StreamError = S>,
    I::Error: ParseError<I::Item, I::Range, I::Position, StreamError = S>, 

type Checkpoint = State<I::Checkpoint, X>

fn checkpoint(&self) -> Self::Checkpoint

Creates a Checkpoint at the current position which can be used to reset the stream later to the current position

fn reset(&mut self, checkpoint: Self::Checkpoint) -> Result<(), Self::Error>

Attempts to reset the stream to an earlier position.

impl<I, X, S> RangeStreamOnce for State<I, X> where
    I: RangeStreamOnce,
    I: ResetStream,
    X: Clone + RangePositioner<I::Item, I::Range>,
    S: StreamError<I::Item, I::Range>,
    I::Error: ParseError<I::Item, I::Range, X::Position, StreamError = S>,
    I::Error: ParseError<I::Item, I::Range, I::Position, StreamError = S>,
    I::Position: Clone + Ord, 

fn uncons_range(
    &mut self,
    size: usize
) -> Result<I::Range, StreamErrorFor<Self>>

Takes size elements from the stream. Fails if the length of the stream is less than size.

fn uncons_while<F>(
    &mut self,
    predicate: F
) -> Result<I::Range, StreamErrorFor<Self>> where
    F: FnMut(I::Item) -> bool, 

Takes items from stream, testing each one with predicate. returns the range of items which passed predicate.

fn uncons_while1<F>(
    &mut self,
    predicate: F
) -> ParseResult<Self::Range, StreamErrorFor<Self>> where
    F: FnMut(Self::Item) -> bool, 

Takes items from stream, testing each one with predicate returns a range of at least one items which passed predicate.

fn distance(&self, end: &Self::Checkpoint) -> usize

Returns the distance between self and end. The returned usize must be so that

impl<I, X, E> FullRangeStream for State<I, X> where
    I: FullRangeStream + ResetStream,
    I::Position: Clone + Ord,
    E: StreamError<I::Item, I::Range>,
    I::Error: ParseError<I::Item, I::Range, X::Position, StreamError = E>,
    I::Error: ParseError<I::Item, I::Range, I::Position, StreamError = E>,
    X: Clone + RangePositioner<I::Item, I::Range>, 

fn range(&self) -> Self::Range

Returns the entire range of self

impl<I: PartialEq, X: PartialEq> PartialEq<State<I, X>> for State<I, X>

fn eq(&self, other: &State<I, X>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &State<I, X>) -> bool

This method tests for !=.

impl<I: Clone, X: Clone> Clone for State<I, X>

fn clone(&self) -> State<I, X>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I: Debug, X: Debug> Debug for State<I, X>

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.