Trait Stream

pub trait Stream: Offset<Self::Checkpoint> + Debug {
    type Token: Debug;
    type Slice: Debug;
    type IterOffsets: Iterator<Item = (usize, Self::Token)>;
    type Checkpoint: Offset + Clone + Debug;

Show 13 methods    // Required methods
    fn iter_offsets(&self) -> Self::IterOffsets;
    fn eof_offset(&self) -> usize;
    fn next_token(&mut self) -> Option<Self::Token>;
    fn offset_for<P>(&self, predicate: P) -> Option<usize>
       where P: Fn(Self::Token) -> bool;
    fn offset_at(&self, tokens: usize) -> Result<usize, Needed>;
    fn next_slice(&mut self, offset: usize) -> Self::Slice;
    fn checkpoint(&self) -> Self::Checkpoint;
    fn reset(&mut self, checkpoint: &Self::Checkpoint);
    fn raw(&self) -> &dyn Debug;

    // Provided methods
    fn peek_token(&self) -> Option<(Self, Self::Token)>
       where Self: Clone { ... }
    fn peek_slice(&self, offset: usize) -> (Self, Self::Slice)
       where Self: Clone { ... }
    fn finish(&mut self) -> Self::Slice { ... }
    fn peek_finish(&self) -> (Self, Self::Slice)
       where Self: Clone { ... }
}

Expand description

Core definition for parser input state

Required Associated Types§

type Token: Debug

The smallest unit being parsed

Example: u8 for &[u8] or char for &str

type Slice: Debug

Sequence of Tokens

Example: &[u8] for Located<&[u8]> or &str for Located<&str>

type IterOffsets: Iterator<Item = (usize, Self::Token)>

Iterate with the offset from the current location

type Checkpoint: Offset + Clone + Debug

A parse location within the stream

Required Methods§

fn iter_offsets(&self) -> Self::IterOffsets

Iterate with the offset from the current location

fn eof_offset(&self) -> usize

Returns the offset to the end of the input

fn next_token(&mut self) -> Option<Self::Token>

Split off the next token from the input

fn offset_for<P>(&self, predicate: P) -> Option<usize>
where P: Fn(Self::Token) -> bool,

Finds the offset of the next matching token

fn offset_at(&self, tokens: usize) -> Result<usize, Needed>

Get the offset for the number of tokens into the stream

This means “0 tokens” will return 0 offset

fn next_slice(&mut self, offset: usize) -> Self::Slice

Split off a slice of tokens from the input

NOTE: For inputs with variable width tokens, like &str’s char, offset might not correspond with the number of tokens. To get a valid offset, use:

§Panic

This will panic if

Indexes must be within bounds of the original input;
Indexes must uphold invariants of the stream, like for str they must lie on UTF-8 sequence boundaries.

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

Save the current parse location within the stream

fn reset(&mut self, checkpoint: &Self::Checkpoint)

Revert the stream to a prior Self::Checkpoint

§Panic

May panic if an invalid Self::Checkpoint is provided

fn raw(&self) -> &dyn Debug

Return the inner-most stream

Provided Methods§

fn peek_token(&self) -> Option<(Self, Self::Token)>
where Self: Clone,

Split off the next token from the input

fn peek_slice(&self, offset: usize) -> (Self, Self::Slice)
where Self: Clone,

Split off a slice of tokens from the input

fn finish(&mut self) -> Self::Slice

Advance to the end of the stream

fn peek_finish(&self) -> (Self, Self::Slice)
where Self: Clone,

Advance to the end of the stream

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types§

impl<'i> Stream for &'i str

type Token = char

type Slice = &'i str

type IterOffsets = CharIndices<'i>

type Checkpoint = Checkpoint<&'i str, &'i str>

fn iter_offsets(&self) -> Self::IterOffsets

fn eof_offset(&self) -> usize

fn next_token(&mut self) -> Option<Self::Token>

fn offset_for<P>(&self, predicate: P) -> Option<usize>
where P: Fn(Self::Token) -> bool,

fn offset_at(&self, tokens: usize) -> Result<usize, Needed>

fn next_slice(&mut self, offset: usize) -> Self::Slice

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

fn reset(&mut self, checkpoint: &Self::Checkpoint)

fn raw(&self) -> &dyn Debug

impl<'i, T> Stream for &'i [T]
where T: Clone + Debug,

type Token = T

type Slice = &'i [T]

type IterOffsets = Enumerate<Cloned<Iter<'i, T>>>

type Checkpoint = Checkpoint<&'i [T], &'i [T]>

fn iter_offsets(&self) -> Self::IterOffsets

fn eof_offset(&self) -> usize

fn next_token(&mut self) -> Option<Self::Token>

fn offset_for<P>(&self, predicate: P) -> Option<usize>
where P: Fn(Self::Token) -> bool,

fn offset_at(&self, tokens: usize) -> Result<usize, Needed>

fn next_slice(&mut self, offset: usize) -> Self::Slice

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

fn reset(&mut self, checkpoint: &Self::Checkpoint)

fn raw(&self) -> &dyn Debug

impl<I> Stream for (I, usize)
where I: Stream<Token = u8> + Clone,

type Token = bool

type Slice = (<I as Stream>::Slice, usize, usize)

type IterOffsets = BitOffsets<I>

type Checkpoint = Checkpoint<(<I as Stream>::Checkpoint, usize), (I, usize)>

fn iter_offsets(&self) -> Self::IterOffsets

fn eof_offset(&self) -> usize

fn next_token(&mut self) -> Option<Self::Token>

fn offset_for<P>(&self, predicate: P) -> Option<usize>
where P: Fn(Self::Token) -> bool,

fn offset_at(&self, tokens: usize) -> Result<usize, Needed>

fn next_slice(&mut self, offset: usize) -> Self::Slice

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

fn reset(&mut self, checkpoint: &Self::Checkpoint)

fn raw(&self) -> &dyn Debug

Implementors§

impl<'i> Stream for &'i BStr

type Token = u8

type Slice = &'i [u8]

type IterOffsets = Enumerate<Cloned<Iter<'i, u8>>>

type Checkpoint = Checkpoint<&'i BStr, &'i BStr>

impl<'i> Stream for &'i Bytes

type Token = u8

type Slice = &'i [u8]

type IterOffsets = Enumerate<Cloned<Iter<'i, u8>>>

type Checkpoint = Checkpoint<&'i Bytes, &'i Bytes>

impl<I: Stream> Stream for Located<I>

type Token = <I as Stream>::Token

type Slice = <I as Stream>::Slice

type IterOffsets = <I as Stream>::IterOffsets

type Checkpoint = Checkpoint<<I as Stream>::Checkpoint, Located<I>>

impl<I: Stream> Stream for Partial<I>

type Token = <I as Stream>::Token

type Slice = <I as Stream>::Slice

type IterOffsets = <I as Stream>::IterOffsets

type Checkpoint = Checkpoint<<I as Stream>::Checkpoint, Partial<I>>

impl<I: Stream, S: Debug> Stream for Stateful<I, S>

type Token = <I as Stream>::Token

type Slice = <I as Stream>::Slice

type IterOffsets = <I as Stream>::IterOffsets

type Checkpoint = Checkpoint<<I as Stream>::Checkpoint, Stateful<I, S>>