Type Alias Substitution

pub type Substitution = Substitution<Interner>;

Interned list of generic arguments for an item. When an item has parent, the Substitution for it contains generic arguments for both its parent and itself. See chalk’s documentation for details.

See Binders for the constraint on the ordering.

Aliased Type

struct Substitution { /* private fields */ }

Implementations

impl<I> Substitution<I>

where I: Interner,

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

Show debug output for the substitution.

impl<I> Substitution<I>

where I: Interner,

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

Tries to create a sequence using an iterator of element-like things.

pub fn from_iter( interner: I, elements: impl IntoIterator<Item = impl CastTo<GenericArg<I>>>, ) -> Substitution<I>

Create a sequence from elements

pub fn from1( interner: I, element: impl CastTo<GenericArg<I>>, ) -> Substitution<I>

Create a sequence from a single element.

impl<I> Substitution<I>

where I: Interner,

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

Get the interned elements.

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

Returns a slice containing the elements.

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

Index into the sequence.

pub fn empty(interner: I) -> Substitution<I>

Create an empty sequence.

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

Check whether this is an empty sequence.

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

Get an iterator over the elements of the sequence.

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

Get the length of the sequence.

impl<I> Substitution<I>

where I: Interner,

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

where T: TypeFoldable<I>,

Apply the substitution to a value.

pub fn type_parameters(&self, interner: I) -> impl Iterator<Item = Ty<I>>

Gets an iterator of all type parameters.

impl<I> Substitution<I>

where I: Interner,

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.

Trait Implementations

impl<I> AsParameters<I> for Substitution<I>

where I: Interner,

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

Convert the current value to parameters.

impl<I> Clone for Substitution<I>

where I: Clone + Interner, <I as Interner>::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> Debug for Substitution<I>

where I: Interner,

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

Formats the value using the given formatter.

impl<I> Display for Substitution<I>

where I: Interner,

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

Formats the value using the given formatter.

impl<I> HasInterner for Substitution<I>

where I: Interner,

type Interner = I

The interner associated with the type.

impl<I> Hash for Substitution<I>

where I: Hash + Interner, <I as Interner>::InternedSubstitution: Hash,

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

where __H: Hasher,

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<I> Ord for Substitution<I>

where I: Ord + Interner, <I as Interner>::InternedSubstitution: Ord,

fn cmp(&self, other: &Substitution<I>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<I> PartialEq for Substitution<I>

where I: PartialEq + Interner, <I as Interner>::InternedSubstitution: PartialEq,

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<I> PartialOrd for Substitution<I>

where I: PartialOrd + Interner, <I as Interner>::InternedSubstitution: PartialOrd,

fn partial_cmp(&self, other: &Substitution<I>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<I> TypeFoldable<I> for Substitution<I>

where I: Interner,

fn try_fold_with<E>( self, folder: &mut dyn FallibleTypeFolder<I, Error = E>, outer_binder: DebruijnIndex, ) -> Result<Substitution<I>, E>

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.

fn fold_with( self, folder: &mut dyn TypeFolder<I, Error = Infallible>, outer_binder: DebruijnIndex, ) -> Self

A convenient alternative to try_fold_with for use with infallible folders. Do not override this method, to ensure coherence with try_fold_with.

impl<I> TypeVisitable<I> for Substitution<I>

where I: Interner,

fn visit_with<B>( &self, visitor: &mut dyn TypeVisitor<I, BreakTy = B>, outer_binder: DebruijnIndex, ) -> ControlFlow<B>

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> Copy for Substitution<I>

where I: Copy + Interner, <I as Interner>::InternedSubstitution: Copy,

impl<I> Eq for Substitution<I>

where I: Eq + Interner, <I as Interner>::InternedSubstitution: Eq,

impl<I> StructuralPartialEq for Substitution<I>

where I: Interner,