Struct chalk_ir::DynTy

pub struct DynTy<I: Interner> {
    pub bounds: Binders<QuantifiedWhereClauses<I>>,
    pub lifetime: Lifetime<I>,
}

A "DynTy" represents a trait object (dyn Trait). Trait objects are conceptually very related to an "existential type" of the form exists<T> { T: Trait } (another example of such type is impl Trait). DynTy represents the bounds on that type.

The "bounds" here represents the unknown self type. So, a type like dyn for<'a> Fn(&'a u32) would be represented with two-levels of binder, as "depicted" here:

exists<type> {
   vec![
       // A QuantifiedWhereClause:
       forall<region> { ^1.0: Fn(&^0.0 u32) }
   ]
}

The outer exists<type> binder indicates that there exists some type that meets the criteria within, but that type is not known. It is referenced within the type using ^1.0, indicating a bound type with debruijn index 1 (i.e., skipping through one level of binder).

Fields

bounds: Binders<QuantifiedWhereClauses<I>>

The unknown self type.

lifetime: Lifetime<I>

Lifetime of the DynTy.

Trait Implementations

impl<I: Clone + Interner> Clone for DynTy<I>

pub fn clone(&self) -> DynTy<I>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I: Interner> Copy for DynTy<I> where
    I::InternedLifetime: Copy,
    I::InternedQuantifiedWhereClauses: Copy,
    I::InternedVariableKinds: Copy, 

impl<I: Interner> Debug for DynTy<I>

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

Formats the value using the given formatter.

impl<I: Eq + Interner> Eq for DynTy<I>

impl<I: Interner> Fold<I> for DynTy<I>

type Result = DynTy<I>

The type of value that will be produced once folding is done. Typically this is Self, unless Self contains borrowed values, in which case owned values are produced (for example, one can fold over a &T value where T: Fold, in which case you get back a T, not a &T).

pub fn fold_with<'i>(
    &self,
    folder: &mut dyn Folder<'i, I>,
    outer_binder: DebruijnIndex
) -> Fallible<Self::Result> where
    I: 'i, 

Apply the given folder folder to self; binders is the number of binders that are in scope when beginning the folder. Typically binders starts as 0, but is adjusted when we encounter Binders<T> in the IR or other similar constructs.

impl<I: Interner> HasInterner for DynTy<I>

type Interner = I

The interner associated with the type.

impl<I: Hash + Interner> Hash for DynTy<I>

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

impl<I: PartialEq + Interner> PartialEq<DynTy<I>> for DynTy<I>

pub fn eq(&self, other: &DynTy<I>) -> bool

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

pub fn ne(&self, other: &DynTy<I>) -> bool

This method tests for !=.

impl<I: Interner> StructuralEq for DynTy<I>

impl<I: Interner> StructuralPartialEq for DynTy<I>

impl<I: Interner> Visit<I> for DynTy<I>

pub fn visit_with<'i, B>(
    &self,
    visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
    outer_binder: DebruijnIndex
) -> ControlFlow<B> where
    I: 'i, 

Apply the given visitor visitor to self; binders is the number of binders that are in scope when beginning the visitor. Typically binders starts as 0, but is adjusted when we encounter Binders<T> in the IR or other similar constructs.

impl<I: Interner> Zip<I> for DynTy<I>

pub fn zip_with<'i, Z: Zipper<'i, I>>(
    zipper: &mut Z,
    variance: Variance,
    a: &Self,
    b: &Self
) -> Fallible<()> where
    I: 'i, 

Uses the zipper to walk through two values, ensuring that they match.