Enum PathStyle

Source

pub(super) enum PathStyle {
    Expr,
    Pat,
    Type,
    Mod,
}

Expand description

Specifies how to parse a path.

Variants§

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Expr

In some contexts, notably in expressions, paths with generic arguments are ambiguous with something else. For example, in expressions segment < .... can be interpreted as a comparison and segment ( .... can be interpreted as a function call. In all such contexts the non-path interpretation is preferred by default for practical reasons, but the path interpretation can be forced by the disambiguator ::, e.g. x<y> - comparisons, x::<y> - unambiguously a path.

Also, a path may never be followed by a :. This means that we can eagerly recover if we encounter it.

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Pat

The same as Expr, but may be followed by a :. For example, this code:

struct S;

let S: S;
//  ^ Followed by a `:`

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Type

In other contexts, notably in types, no ambiguity exists and paths can be written without the disambiguator, e.g., x<y> - unambiguously a path. Paths with disambiguators are still accepted, x::<Y> - unambiguously a path too.

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Mod

A path with generic arguments disallowed, e.g., foo::bar::Baz, used in imports, visibilities or attributes. Technically, this variant is unnecessary and e.g., Expr can be used instead (paths in “mod” contexts have to be checked later for absence of generic arguments anyway, due to macros), but it is used to avoid weird suggestions about expected tokens when something goes wrong.

Enum PathStyleCopy item path

Variants§

Expr

Pat

Type

Mod

Implementations§

impl PathStyle

fn has_generic_ambiguity(&self) -> bool

Trait Implementations§

impl Clone for PathStyle

fn clone(&self) -> PathStyle

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

impl PartialEq for PathStyle

fn eq(&self, other: &PathStyle) -> bool

fn ne(&self, other: &Rhs) -> bool

impl Copy for PathStyle

impl StructuralPartialEq for PathStyle

Auto Trait Implementations§

impl DynSend for PathStyle

impl DynSync for PathStyle

impl Freeze for PathStyle

impl RefUnwindSafe for PathStyle

impl Send for PathStyle

impl Sync for PathStyle

impl Unpin for PathStyle

impl UnwindSafe for PathStyle

Blanket Implementations§

impl<T> Aligned for T

const ALIGN: Alignment = _

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

fn type_id(&self) -> TypeId

impl<T> AnyEq for Twhere T: Any + PartialEq,

fn equals(&self, other: &(dyn Any + 'static)) -> bool

fn as_any(&self) -> &(dyn Any + 'static)

impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for Twhere T: Copy,

fn allocate_on(self, arena: &'tcx Arena<'tcx>) -> &'tcx mut T

fn allocate_from_iter( arena: &'tcx Arena<'tcx>, iter: impl IntoIterator<Item = T>, ) -> &'tcx mut [T]

impl<T> Borrow<T> for Twhere T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere T: ?Sized,

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

impl<T> CloneToUninit for Twhere T: Clone,

unsafe fn clone_to_uninit(&self, dst: *mut u8)

impl<T, R> CollectAndApply<T, R> for T

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

type Output = R

impl<T> Filterable for T

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

impl<T> From<T> for T

fn from(t: T) -> T

impl<T> Instrument for T

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

fn in_current_span(self) -> Instrumented<Self>

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

fn into(self) -> U

impl<T> IntoEither for T

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

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>where F: FnOnce(&Self) -> bool,

impl<T> Pointable for T

const ALIGN: usize = _

type Init = T

unsafe fn init(init: <T as Pointable>::Init) -> usize

unsafe fn deref<'a>(ptr: usize) -> &'a T

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

unsafe fn drop(ptr: usize)

impl<T> Same for T

type Output = T

impl<T> ToOwned for Twhere T: Clone,

type Owned = T

fn to_owned(&self) -> T

fn clone_into(&self, target: &mut T)

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

impl<I, T, U> Upcast<I, U> for Twhere U: UpcastFrom<I, T>,

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

Enum PathStyle

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

impl<T> AnyEq for T
where T: Any + PartialEq,

impl<'tcx, T> ArenaAllocatable<'tcx, IsCopy> for T
where T: Copy,

impl<T> Borrow<T> for T
where T: ?Sized,

impl<T> BorrowMut<T> for T
where T: ?Sized,

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

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

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

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

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

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

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

impl<I, T, U> Upcast<I, U> for T
where U: UpcastFrom<I, T>,

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

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

impl<'a, T> Captures<'a> for T
where T: ?Sized,

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

impl<T> MaybeSendSync for T
where T: Send + Sync,