Enum rustc_expand::mbe::macro_parser::NamedMatch

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pub(crate) enum NamedMatch {
    MatchedSeq(Vec<NamedMatch>),
    MatchedSingle(ParseNtResult),
}
Expand description

NamedMatch is a pattern-match result for a single metavar. All MatchedNonterminals in the NamedMatch have the same non-terminal type (expr, item, etc).

The in-memory structure of a particular NamedMatch represents the match that occurred when a particular subset of a matcher was applied to a particular token tree.

The width of each MatchedSeq in the NamedMatch, and the identity of the MatchedNtNonTtss, will depend on the token tree it was applied to: each MatchedSeq corresponds to a single repetition in the originating token tree. The depth of the NamedMatch structure will therefore depend only on the nesting depth of repetitions in the originating token tree it was derived from.

In layperson’s terms: NamedMatch will form a tree representing nested matches of a particular meta variable. For example, if we are matching the following macro against the following invocation…

macro_rules! foo {
  ($($($x:ident),+);+) => {}
}

foo!(a, b, c, d; a, b, c, d, e);

Then, the tree will have the following shape:

MatchedSeq([
  MatchedSeq([
    MatchedNonterminal(a),
    MatchedNonterminal(b),
    MatchedNonterminal(c),
    MatchedNonterminal(d),
  ]),
  MatchedSeq([
    MatchedNonterminal(a),
    MatchedNonterminal(b),
    MatchedNonterminal(c),
    MatchedNonterminal(d),
    MatchedNonterminal(e),
  ])
])

Variants§

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MatchedSeq(Vec<NamedMatch>)

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MatchedSingle(ParseNtResult)

Trait Implementations§

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impl Clone for NamedMatch

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fn clone(&self) -> NamedMatch

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 Debug for NamedMatch

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

Formats the value using the given formatter. Read more

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Blanket Implementations§

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impl<T> Aligned for T

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const ALIGN: Alignment = _

Alignment of Self.
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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, R> CollectAndApply<T, R> for T

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fn collect_and_apply<I, F>(iter: I, f: F) -> R
where I: Iterator<Item = T>, F: FnOnce(&[T]) -> R,

Equivalent to f(&iter.collect::<Vec<_>>()).

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type Output = R

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impl<T> Filterable for T

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fn filterable( self, filter_name: &'static str, ) -> RequestFilterDataProvider<T, fn(_: DataRequest<'_>) -> bool>

Creates a filterable data provider with the given name for debugging. 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> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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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> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> Same for T

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type Output = T

Should always be Self
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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, 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.
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impl<I, T, U> Upcast<I, U> for T
where U: UpcastFrom<I, T>,

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fn upcast(self, interner: I) -> U

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impl<I, T> UpcastFrom<I, T> for T

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fn upcast_from(from: T, _tcx: I) -> T

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impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V

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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
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impl<'a, T> Captures<'a> for T
where T: ?Sized,

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impl<T> ErasedDestructor for T
where T: 'static,

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 32 bytes

Size for each variant:

  • MatchedSeq: 32 bytes
  • MatchedSingle: 32 bytes