Struct chalk_ir::Substitution

pub struct Substitution<I: Interner> { /* fields omitted */ }

A mapping of inference variables to instantiations thereof.

Implementations

impl<I: Interner> Substitution<I>

pub fn debug<'a>(&'a self, interner: &'a I) -> SubstitutionDebug<'a, I>

Show debug output for the substitution.

impl<I: Interner> Substitution<I>

pub fn with_angle(&self, interner: &I) -> Angle<GenericArg<I>>

Displays the substitution in the form < P0, .. Pn >, or (if the substitution is empty) as an empty string.

impl<I: Interner> Substitution<I>

pub fn from(
    interner: &I,
    parameters: impl IntoIterator<Item = impl CastTo<GenericArg<I>>>
) -> Self

Create a substitution from parameters.

pub fn from_fallible<E>(
    interner: &I,
    parameters: impl IntoIterator<Item = Result<impl CastTo<GenericArg<I>>, E>>
) -> Result<Self, E>

Try to create a substitution from parameters.

pub fn interned(&self) -> &I::InternedSubstitution

Get the interned representation of the substitution.

pub fn at(&self, interner: &I, index: usize) -> &GenericArg<I>

Index into the list of parameters.

pub fn from1(interner: &I, parameter: impl CastTo<GenericArg<I>>) -> Self

Create a substitution from a single parameter.

pub fn empty(interner: &I) -> Self

Create an empty substitution.

pub fn is_empty(&self, interner: &I) -> bool

Check whether this is an empty substitution.

pub fn iter(&self, interner: &I) -> Iter<GenericArg<I>>

Get an iterator over the parameters of the substitution.

pub fn parameters(&self, interner: &I) -> &[GenericArg<I>]

Get the parameters associated with a substitution.

pub fn len(&self, interner: &I) -> usize

Get the length of the substitution (number of parameters).

pub fn is_identity_subst(&self, interner: &I) -> bool

A substitution is an identity substitution if it looks like this

?0 := ?0
?1 := ?1
?2 := ?2
...

Basically, each value is mapped to a type or lifetime with its same index.

pub fn apply<T>(&self, value: &T, interner: &I) -> T::Result where
    T: Fold<I, I>, 

Apply the substitution to a value.

Trait Implementations

impl<I: Interner> AsParameters<I> for Substitution<I>

fn as_parameters(&self, interner: &I) -> &[GenericArg<I>]

Convert the current value to parameters.

impl<I: Clone + Interner> Clone for Substitution<I> where
    I::InternedSubstitution: Clone, 

fn clone(&self) -> Substitution<I>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<I: Copy + Interner> Copy for Substitution<I> where
    I::InternedSubstitution: Copy, 

impl<I: Interner> Debug for Substitution<I>

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

Formats the value using the given formatter.

impl<I: Interner> Display for Substitution<I>

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

Formats the value using the given formatter.

impl<I: Eq + Interner> Eq for Substitution<I> where
    I::InternedSubstitution: Eq, 

impl<I: Interner, TI: TargetInterner<I>> Fold<I, TI> for Substitution<I>

type Result = Substitution<TI>

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).

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

type Interner = I

The interner associated with the type.

impl<I: Hash + Interner> Hash for Substitution<I> where
    I::InternedSubstitution: Hash, 

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<I: PartialEq + Interner> PartialEq<Substitution<I>> for Substitution<I> where
    I::InternedSubstitution: PartialEq, 

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

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

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

This method tests for !=.

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

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

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

fn visit_with<'i, R: VisitResult>(
    &self,
    visitor: &mut dyn Visitor<'i, I, Result = R>,
    outer_binder: DebruijnIndex
) -> R 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 Substitution<I>

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

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