Enum chalk_ir::DomainGoal [−][src]
pub enum DomainGoal<I: Interner> { Holds(WhereClause<I>), WellFormed(WellFormed<I>), FromEnv(FromEnv<I>), Normalize(Normalize<I>), IsLocal(Ty<I>), IsUpstream(Ty<I>), IsFullyVisible(Ty<I>), LocalImplAllowed(TraitRef<I>), Compatible, DownstreamType(Ty<I>), Reveal, ObjectSafe(TraitId<I>), }
Expand description
A “domain goal” is a goal that is directly about Rust, rather than a pure logical statement. As much as possible, the Chalk solver should avoid decomposing this enum, and instead treat its values opaquely.
Variants
Holds(WhereClause<I>)
Simple goal that is true if the where clause is true.
WellFormed(WellFormed<I>)
True if the type or trait ref is well-formed.
FromEnv(FromEnv<I>)
True if the trait ref can be derived from in-scope where clauses.
Normalize(Normalize<I>)
True if the alias type can be normalized to some other type
IsLocal(Ty<I>)
True if a type is considered to have been “defined” by the current crate. This is true for
a struct Foo { }
but false for a #[upstream] struct Foo { }
. However, for fundamental types
like Box<T>
, it is true if T
is local.
IsUpstream(Ty<I>)
True if a type is not considered to have been “defined” by the current crate. This is
false for a struct Foo { }
but true for a #[upstream] struct Foo { }
. However, for
fundamental types like Box<T>
, it is true if T
is upstream.
IsFullyVisible(Ty<I>)
True if a type and its input types are fully visible, known types. That is, there are no unknown type parameters anywhere in this type.
More formally, for each struct S<P0..Pn>: forall<P0..Pn> { IsFullyVisible(S<P0…Pn>) :- IsFullyVisible(P0), … IsFullyVisible(Pn) }
Note that any of these types can have lifetimes in their parameters too, but we only consider type parameters.
LocalImplAllowed(TraitRef<I>)
Used to dictate when trait impls are allowed in the current (local) crate based on the orphan rules.
LocalImplAllowed(T: Trait)
is true if the type T is allowed to impl trait Trait in
the current crate. Under the current rules, this is unconditionally true for all types if
the Trait is considered to be “defined” in the current crate. If that is not the case, then
LocalImplAllowed(T: Trait)
can still be true if IsLocal(T)
is true.
Used to activate the “compatible modality” rules. Rules that introduce predicates that have to do with “all compatible universes” should depend on this clause so that they only apply if this is present.
DownstreamType(Ty<I>)
Used to indicate that a given type is in a downstream crate. Downstream crates contain the current crate at some level of their dependencies.
Since chalk does not actually see downstream types, this is usually introduced with implication on a fresh, universally quantified type.
forall
This makes a new type T
available and makes DownstreamType(T)
provable for that type.
Used to activate the “reveal mode”, in which opaque (impl Trait
) types can be equated
to their actual type.
ObjectSafe(TraitId<I>)
Used to indicate that a trait is object safe.
Implementations
Convert Implemented(...)
into FromEnv(...)
, but leave other
goals unchanged.
Lists generic arguments that are inputs to this domain goal.
Trait Implementations
Cast a value to type T
.
Cast a value to type T
.
Cast a value to type T
.
Cast a value to type T
.
Cast a value to type T
.
fn could_match(
&self,
interner: &I,
db: &dyn UnificationDatabase<I>,
other: &DomainGoal<I>
) -> bool
[src]
fn could_match(
&self,
interner: &I,
db: &dyn UnificationDatabase<I>,
other: &DomainGoal<I>
) -> bool
[src]Checks whether self
and other
could possibly match.
fn could_match(
&self,
interner: &I,
db: &dyn UnificationDatabase<I>,
other: &DomainGoal<I>
) -> bool
[src]
fn could_match(
&self,
interner: &I,
db: &dyn UnificationDatabase<I>,
other: &DomainGoal<I>
) -> bool
[src]Checks whether self
and other
could possibly match.
type Result = DomainGoal<I>
type Result = DomainGoal<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
). Read more
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. Read more
type Interner = I
type Interner = I
The interner associated with the type.
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
This method tests for !=
.
fn super_visit_with<'i, B>(
&self,
visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
[src]
fn super_visit_with<'i, B>(
&self,
visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
[src]Recursively visits the type contents.
fn visit_with<'i, B>(
&self,
visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
[src]
fn visit_with<'i, B>(
&self,
visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
[src]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. Read more
impl<I: Interner> Copy for DomainGoal<I> where
I::InternedSubstitution: Copy,
I::InternedLifetime: Copy,
I::InternedType: Copy,
[src]Auto Trait Implementations
impl<I> RefUnwindSafe for DomainGoal<I> where
<I as Interner>::DefId: RefUnwindSafe,
<I as Interner>::InternedLifetime: RefUnwindSafe,
<I as Interner>::InternedSubstitution: RefUnwindSafe,
<I as Interner>::InternedType: RefUnwindSafe,
impl<I> Send for DomainGoal<I> where
<I as Interner>::DefId: Send,
<I as Interner>::InternedLifetime: Send,
<I as Interner>::InternedSubstitution: Send,
<I as Interner>::InternedType: Send,
impl<I> Sync for DomainGoal<I> where
<I as Interner>::DefId: Sync,
<I as Interner>::InternedLifetime: Sync,
<I as Interner>::InternedSubstitution: Sync,
<I as Interner>::InternedType: Sync,
impl<I> Unpin for DomainGoal<I> where
<I as Interner>::DefId: Unpin,
<I as Interner>::InternedLifetime: Unpin,
<I as Interner>::InternedSubstitution: Unpin,
<I as Interner>::InternedType: Unpin,
impl<I> UnwindSafe for DomainGoal<I> where
<I as Interner>::DefId: UnwindSafe,
<I as Interner>::InternedLifetime: UnwindSafe,
<I as Interner>::InternedSubstitution: UnwindSafe,
<I as Interner>::InternedType: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more
Cast a value to type U
using CastTo
.
Cast a value to type T
.
Cast a value to type T
.
Cast a value to type T
.
Cast a value to type T
.
Cast a value to type T
.
Cast a value to type T
.
impl<T, I> CouldMatch<T> for T where
T: Zip<I> + HasInterner<Interner = I> + ?Sized,
I: Interner,
[src]
impl<T, I> CouldMatch<T> for T where
T: Zip<I> + HasInterner<Interner = I> + ?Sized,
I: Interner,
[src]Checks whether self
and other
could possibly match.
Shifts this term in one level of binders.
Shifts a term valid at outer_binder
so that it is
valid at the innermost binder. See DebruijnIndex::shifted_in_from
for a detailed explanation. Read more
Shifts a term valid at the innermost binder so that it is
valid at outer_binder
. See DebruijnIndex::shifted_out_to
for a detailed explanation. Read more
Shifts this term out one level of binders.