Enum ra_ap_hir_ty::Ty

pub enum Ty {
    Apply(ApplicationTy),
    Projection(ProjectionTy),
    Opaque(OpaqueTy),
    Placeholder(TypeParamId),
    Bound(BoundVar),
    Infer(InferTy),
    Dyn(Arc<[GenericPredicate]>),
    Unknown,
}

A type.

See also the TyKind enum in rustc (librustc/ty/sty.rs), which represents the same thing (but in a different way).

This should be cheap to clone.

Variants

Apply(ApplicationTy)

A nominal type with (maybe 0) type parameters. This might be a primitive type like bool, a struct, tuple, function pointer, reference or several other things.

Projection(ProjectionTy)

A "projection" type corresponds to an (unnormalized) projection like <P0 as Trait<P1..Pn>>::Foo. Note that the trait and all its parameters are fully known.

Opaque(OpaqueTy)

An opaque type (impl Trait).

This is currently only used for return type impl trait; each instance of impl Trait in a return type gets its own ID.

Placeholder(TypeParamId)

A placeholder for a type parameter; for example, T in fn f<T>(x: T) {} when we're type-checking the body of that function. In this situation, we know this stands for some type, but don't know the exact type.

Bound(BoundVar)

A bound type variable. This is used in various places: when representing some polymorphic type like the type of function fn f<T>, the type parameters get turned into variables; during trait resolution, inference variables get turned into bound variables and back; and in Dyn the Self type is represented with a bound variable as well.

Infer(InferTy)

A type variable used during type checking.

Dyn(Arc<[GenericPredicate]>)

A trait object (dyn Trait or bare Trait in pre-2018 Rust).

The predicates are quantified over the Self type, i.e. Ty::Bound(0) represents the Self type inside the bounds. This is currently implicit; Chalk has the Binders struct to make it explicit, but it didn't seem worth the overhead yet.

Unknown

A placeholder for a type which could not be computed; this is propagated to avoid useless error messages. Doubles as a placeholder where type variables are inserted before type checking, since we want to try to infer a better type here anyway -- for the IDE use case, we want to try to infer as much as possible even in the presence of type errors.

Implementations

impl Ty

pub fn def_crates(
    &self,
    db: &dyn HirDatabase,
    cur_crate: CrateId
) -> Option<ArrayVec<[CrateId; 2]>>

impl Ty

pub fn from_hir(ctx: &TyLoweringContext<'_>, type_ref: &TypeRef) -> Self

pub fn from_hir_ext(
    ctx: &TyLoweringContext<'_>,
    type_ref: &TypeRef
) -> (Self, Option<TypeNs>)

impl Ty

pub fn simple(ctor: TypeCtor) -> Ty

pub fn apply_one(ctor: TypeCtor, param: Ty) -> Ty

pub fn apply(ctor: TypeCtor, parameters: Substs) -> Ty

pub fn unit() -> Self

pub fn fn_ptr(sig: FnSig) -> Self

pub fn as_reference(&self) -> Option<(&Ty, Mutability)>

pub fn as_reference_or_ptr(&self) -> Option<(&Ty, Rawness, Mutability)>

pub fn strip_references(&self) -> &Ty

pub fn as_adt(&self) -> Option<(AdtId, &Substs)>

pub fn as_tuple(&self) -> Option<&Substs>

pub fn is_never(&self) -> bool

pub fn dyn_trait_ref(&self) -> Option<&TraitRef>

If this is a dyn Trait type, this returns the Trait part.

pub fn dyn_trait(&self) -> Option<TraitId>

If this is a dyn Trait, returns that trait.

pub fn callable_sig(&self, db: &dyn HirDatabase) -> Option<FnSig>

pub fn apply_substs(self, substs: Substs) -> Ty

If this is a type with type parameters (an ADT or function), replaces the Substs for these type parameters with the given ones. (So e.g. if self is Option<_> and the substs contain u32, we'll have Option<u32> afterwards.)

pub fn substs(&self) -> Option<Substs>

Returns the type parameters of this type if it has some (i.e. is an ADT or function); so if self is Option<u32>, this returns the u32.

pub fn impl_trait_bounds(
    &self,
    db: &dyn HirDatabase
) -> Option<Vec<GenericPredicate>>

pub fn associated_type_parent_trait(
    &self,
    db: &dyn HirDatabase
) -> Option<TraitId>

Trait Implementations

impl Clone for Ty

fn clone(&self) -> Ty

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Ty

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

Formats the value using the given formatter.

impl Eq for Ty

impl Hash for Ty

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl<'_> HirDisplay for &'_ Ty

fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError>

fn display<'a>(&'a self, db: &'a dyn HirDatabase) -> HirDisplayWrapper<'a, Self> where
    Self: Sized, 

Returns a Displayable type that is human-readable. Use this for showing types to the user (e.g. diagnostics)

fn display_truncated<'a>(
    &'a self,
    db: &'a dyn HirDatabase,
    max_size: Option<usize>
) -> HirDisplayWrapper<'a, Self> where
    Self: Sized, 

Returns a Displayable type that is human-readable and tries to be succinct. Use this for showing types to the user where space is constrained (e.g. doc popups)

fn display_source_code<'a>(
    &'a self,
    db: &'a dyn HirDatabase,
    module_id: ModuleId
) -> Result<String, DisplaySourceCodeError>

Returns a String representation of self that can be inserted into the given module. Use this when generating code (e.g. assists)

impl HirDisplay for Ty

fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError>

fn display<'a>(&'a self, db: &'a dyn HirDatabase) -> HirDisplayWrapper<'a, Self> where
    Self: Sized, 

Returns a Displayable type that is human-readable. Use this for showing types to the user (e.g. diagnostics)

fn display_truncated<'a>(
    &'a self,
    db: &'a dyn HirDatabase,
    max_size: Option<usize>
) -> HirDisplayWrapper<'a, Self> where
    Self: Sized, 

Returns a Displayable type that is human-readable and tries to be succinct. Use this for showing types to the user where space is constrained (e.g. doc popups)

fn display_source_code<'a>(
    &'a self,
    db: &'a dyn HirDatabase,
    module_id: ModuleId
) -> Result<String, DisplaySourceCodeError>

Returns a String representation of self that can be inserted into the given module. Use this when generating code (e.g. assists)

impl PartialEq<Ty> for Ty

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl StructuralEq for Ty

impl StructuralPartialEq for Ty

impl TypeWalk for Ty

fn walk(&self, f: &mut impl FnMut(&Ty))

fn walk_mut_binders(
    &mut self,
    f: &mut impl FnMut(&mut Ty, DebruijnIndex),
    binders: DebruijnIndex
)

Walk the type, counting entered binders.

fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty))

fn fold_binders(
    self,
    f: &mut impl FnMut(Ty, DebruijnIndex) -> Ty,
    binders: DebruijnIndex
) -> Self where
    Self: Sized, 

fn fold(self, f: &mut impl FnMut(Ty) -> Ty) -> Self where
    Self: Sized, 

fn subst_bound_vars(self, substs: &Substs) -> Self where
    Self: Sized, 

Substitutes Ty::Bound vars with the given substitution.

fn subst_bound_vars_at_depth(
    self,
    substs: &Substs,
    depth: DebruijnIndex
) -> Self where
    Self: Sized, 

Substitutes Ty::Bound vars with the given substitution.

fn shift_bound_vars(self, n: DebruijnIndex) -> Self where
    Self: Sized, 

Shifts up debruijn indices of Ty::Bound vars by n.