Struct move_model::ty::Substitution

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pub struct Substitution { /* private fields */ }
Expand description

A type substitution.

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impl Substitution

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pub fn new() -> Self

Creates a new substitution.

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pub fn bind(&mut self, var: u16, ty: Type)

Binds the type variables.

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pub fn specialize(&self, t: &Type) -> Type

Specializes the type, substituting all variables bound in this substitution.

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pub fn get_substitution(&self, var: u16, shallow: bool) -> Option<Type>

Return either a shallow or deep substitution of the type variable.

If deep substitution is requested, follow down the substitution chain until either

  • Some(ty) when the final type is not a type variable or
  • None when the final type variable does not have a substitution
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pub fn unify( &mut self, variance: Variance, t1: &Type, t2: &Type ) -> Result<Type, TypeUnificationError>

Unify two types, returning the unified type.

This currently implements the following notion of type compatibility:

    1. References are dropped (i.e. &T and T are compatible)
    1. All integer types are compatible if co-variance is allowed.
    1. With the joint effect of 1) and 2), if (P, Q) is compatible under co-variance, (&P, Q), (P, &Q), and (&P, &Q) are all compatible under co-variance.
    1. If in two tuples (P1, P2, …, Pn) and (Q1, Q2, …, Qn), all (Pi, Qi) pairs are compatible under co-variance, then the two tuples are compatible under co-variance.

The substitution will be refined by variable assignments as needed to perform unification. If unification fails, the substitution will be in some intermediate state; to implement transactional unification, the substitution must be cloned before calling this.

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impl Clone for Substitution

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fn clone(&self) -> Substitution

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for Substitution

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

Formats the value using the given formatter. Read more
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impl Default for Substitution

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fn default() -> Self

Returns the “default value” for a type. Read more

Auto Trait Implementations§

Blanket Implementations§

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

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

const: unstable · source§

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

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

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

const: unstable · 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.

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impl<T> ToOwned for Twhere T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

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

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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

The type returned in the event of a conversion error.
const: unstable · source§

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

Performs the conversion.
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impl<V, T> VZip<V> for Twhere V: MultiLane<T>,

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fn vzip(self) -> V