Struct winnow::stream::Stateful

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pub struct Stateful<I, S> {
    pub input: I,
    pub state: S,
}
Expand description

Thread global state through your parsers

Use cases

  • Recursion checks
  • Error recovery
  • Debugging

§Example


#[derive(Debug)]
struct State<'s>(&'s mut u32);

impl<'s> State<'s> {
    fn count(&mut self) {
        *self.0 += 1;
    }
}

type Stream<'is> = Stateful<&'is str, State<'is>>;

fn word<'s>(i: &mut Stream<'s>) -> PResult<&'s str> {
  i.state.count();
  alpha1.parse_next(i)
}

let data = "Hello";
let mut state = 0;
let input = Stream { input: data, state: State(&mut state) };
let output = word.parse(input).unwrap();
assert_eq!(state, 1);

Fields§

§input: I

Inner input being wrapped in state

§state: S

User-provided state

Trait Implementations§

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impl<I, S> AsBStr for Stateful<I, S>
where I: AsBStr,

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fn as_bstr(&self) -> &[u8]

Casts the input type to a byte slice
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impl<I, S> AsBytes for Stateful<I, S>
where I: AsBytes,

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fn as_bytes(&self) -> &[u8]

Casts the input type to a byte slice
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impl<I, S> AsRef<I> for Stateful<I, S>

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fn as_ref(&self) -> &I

Converts this type into a shared reference of the (usually inferred) input type.
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impl<I: Clone, S: Clone> Clone for Stateful<I, S>

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fn clone(&self) -> Stateful<I, S>

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl<I, S, U> Compare<U> for Stateful<I, S>
where I: Compare<U>,

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fn compare(&self, other: U) -> CompareResult

Compares self to another value for equality
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impl<I: Debug, S: Debug> Debug for Stateful<I, S>

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

Formats the value using the given formatter. Read more
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impl<I: Default, S: Default> Default for Stateful<I, S>

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fn default() -> Stateful<I, S>

Returns the “default value” for a type. Read more
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impl<I, S> Deref for Stateful<I, S>

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type Target = I

The resulting type after dereferencing.
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fn deref(&self) -> &Self::Target

Dereferences the value.
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impl<I: Display, S> Display for Stateful<I, S>

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

Formats the value using the given formatter. Read more
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impl<I, S, T> FindSlice<T> for Stateful<I, S>
where I: FindSlice<T>,

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fn find_slice(&self, substr: T) -> Option<Range<usize>>

Returns the offset of the slice if it is found
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impl<I, S> Location for Stateful<I, S>
where I: Location,

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fn location(&self) -> usize

Number of indices input has advanced since start of parsing
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impl<I, S> Offset<<Stateful<I, S> as Stream>::Checkpoint> for Stateful<I, S>
where I: Stream, S: Debug,

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fn offset_from(&self, other: &<Stateful<I, S> as Stream>::Checkpoint) -> usize

Offset between the first byte of start and the first byte of selfa Read more
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impl<I, S> Offset for Stateful<I, S>
where I: Stream, S: Clone + Debug,

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fn offset_from(&self, start: &Self) -> usize

Offset between the first byte of start and the first byte of selfa Read more
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impl<I: PartialEq, S: PartialEq> PartialEq for Stateful<I, S>

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fn eq(&self, other: &Stateful<I, S>) -> bool

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<I, S> SliceLen for Stateful<I, S>
where I: SliceLen,

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fn slice_len(&self) -> usize

Calculates the input length, as indicated by its name, and the name of the trait itself
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impl<I: Stream, S: Debug> Stream for Stateful<I, S>

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type Token = <I as Stream>::Token

The smallest unit being parsed Read more
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type Slice = <I as Stream>::Slice

Sequence of Tokens Read more
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type IterOffsets = <I as Stream>::IterOffsets

Iterate with the offset from the current location
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type Checkpoint = Checkpoint<<I as Stream>::Checkpoint, Stateful<I, S>>

A parse location within the stream
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fn iter_offsets(&self) -> Self::IterOffsets

Iterate with the offset from the current location
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fn eof_offset(&self) -> usize

Returns the offset to the end of the input
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fn next_token(&mut self) -> Option<Self::Token>

Split off the next token from the input
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fn offset_for<P>(&self, predicate: P) -> Option<usize>
where P: Fn(Self::Token) -> bool,

Finds the offset of the next matching token
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fn offset_at(&self, tokens: usize) -> Result<usize, Needed>

Get the offset for the number of tokens into the stream Read more
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fn next_slice(&mut self, offset: usize) -> Self::Slice

Split off a slice of tokens from the input Read more
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fn checkpoint(&self) -> Self::Checkpoint

Save the current parse location within the stream
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fn reset(&mut self, checkpoint: &Self::Checkpoint)

Revert the stream to a prior Self::Checkpoint Read more
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fn raw(&self) -> &dyn Debug

Return the inner-most stream
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fn finish(&mut self) -> Self::Slice

Advance to the end of the stream
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impl<I, S> StreamIsPartial for Stateful<I, S>
where I: StreamIsPartial,

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type PartialState = <I as StreamIsPartial>::PartialState

Whether the stream is currently partial or complete
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fn complete(&mut self) -> Self::PartialState

Mark the stream is complete
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fn restore_partial(&mut self, state: Self::PartialState)

Restore the stream back to its previous state
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fn is_partial_supported() -> bool

Report whether the Stream is can ever be incomplete
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fn is_partial(&self) -> bool

Report whether the Stream is currently incomplete
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impl<I, S> UpdateSlice for Stateful<I, S>
where I: UpdateSlice, S: Clone + Debug,

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fn update_slice(self, inner: Self::Slice) -> Self

Convert an Output type to be used as Stream
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impl<I: Copy, S: Copy> Copy for Stateful<I, S>

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impl<I: Eq, S: Eq> Eq for Stateful<I, S>

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impl<I, S> StructuralPartialEq for Stateful<I, S>

Auto Trait Implementations§

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impl<I, S> Freeze for Stateful<I, S>
where I: Freeze, S: Freeze,

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impl<I, S> RefUnwindSafe for Stateful<I, S>

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impl<I, S> Send for Stateful<I, S>
where I: Send, S: Send,

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impl<I, S> Sync for Stateful<I, S>
where I: Sync, S: Sync,

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impl<I, S> Unpin for Stateful<I, S>
where I: Unpin, S: Unpin,

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impl<I, S> UnwindSafe for Stateful<I, S>
where I: UnwindSafe, S: UnwindSafe,

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T> ToString for T
where T: Display + ?Sized,

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default fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.