rustc_parse::parser::item

Struct FnParseMode

source
pub(crate) struct FnParseMode {
    pub(super) req_name: fn(_: Edition) -> bool,
    pub(super) req_body: bool,
}
Expand description

Parsing configuration for functions.

The syntax of function items is slightly different within trait definitions, impl blocks, and modules. It is still parsed using the same code, just with different flags set, so that even when the input is wrong and produces a parse error, it still gets into the AST and the rest of the parser and type checker can run.

Fields§

§req_name: fn(_: Edition) -> bool

A function pointer that decides if, per-parameter p, p must have a pattern or just a type. This field affects parsing of the parameters list.

fn foo(alef: A) -> X { X::new() }
       -----^^ affects parsing this part of the function signature
       |
       if req_name returns false, then this name is optional

fn bar(A) -> X;
       ^
       |
       if req_name returns true, this is an error

Calling this function pointer should only return false if:

  • The item is being parsed inside of a trait definition. Within an impl block or a module, it should always evaluate to true.
  • The span is from Edition 2015. In particular, you can get a 2015 span inside a 2021 crate using macros.
§req_body: bool

If this flag is set to true, then plain, semicolon-terminated function prototypes are not allowed here.

fn foo(alef: A) -> X { X::new() }
                     ^^^^^^^^^^^^
                     |
                     this is always allowed

fn bar(alef: A, bet: B) -> X;
                            ^
                            |
                            if req_body is set to true, this is an error

This field should only be set to false if the item is inside of a trait definition or extern block. Within an impl block or a module, it should always be set to true.

Trait Implementations§

source§

impl Clone for FnParseMode

source§

fn clone(&self) -> FnParseMode

Returns a copy of the value. Read more
source§

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

Performs copy-assignment from source. Read more
source§

impl Copy for FnParseMode

Auto Trait Implementations§

Blanket Implementations§

source§

impl<T> Aligned for T

source§

const ALIGN: Alignment = _

Alignment of Self.
source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

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

source§

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

source§

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

source§

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

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

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

source§

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

Mutably borrows from an owned value. Read more
source§

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

source§

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

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
source§

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

source§

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<_>>()).

source§

type Output = R

source§

impl<T> Filterable for T

source§

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
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T> Instrument for T

source§

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

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
source§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
source§

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

source§

fn into(self) -> U

Calls U::from(self).

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

source§

impl<T> IntoEither for T

source§

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
source§

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
source§

impl<T> Pointable for T

source§

const ALIGN: usize = _

The alignment of pointer.
source§

type Init = T

The type for initializers.
source§

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

Initializes a with the given initializer. Read more
source§

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

Dereferences the given pointer. Read more
source§

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

Mutably dereferences the given pointer. Read more
source§

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
source§

impl<T> Same for T

source§

type Output = T

Should always be Self
source§

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

source§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

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

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

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

source§

type Error = Infallible

The type returned in the event of a conversion error.
source§

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

Performs the conversion.
source§

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

source§

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

The type returned in the event of a conversion error.
source§

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

Performs the conversion.
source§

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

source§

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

source§

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

source§

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

source§

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

source§

fn vzip(self) -> V

source§

impl<T> WithSubscriber for T

source§

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
source§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
source§

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

source§

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

source§

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

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: 16 bytes