Struct chalk_solve::infer::unify::OccursCheck
source · struct OccursCheck<'u, 't, I: Interner> {
unifier: &'u mut Unifier<'t, I>,
var: EnaVariable<I>,
universe_index: UniverseIndex,
}
Fields§
§unifier: &'u mut Unifier<'t, I>
§var: EnaVariable<I>
§universe_index: UniverseIndex
Implementations§
source§impl<'u, 't, I: Interner> OccursCheck<'u, 't, I>
impl<'u, 't, I: Interner> OccursCheck<'u, 't, I>
fn new( unifier: &'u mut Unifier<'t, I>, var: EnaVariable<I>, universe_index: UniverseIndex, ) -> Self
Trait Implementations§
source§impl<'i, I: Interner> FallibleTypeFolder<I> for OccursCheck<'_, 'i, I>
impl<'i, I: Interner> FallibleTypeFolder<I> for OccursCheck<'_, 'i, I>
§type Error = NoSolution
type Error = NoSolution
The type this folder returns when folding fails. This is
commonly
NoSolution
.source§fn as_dyn(&mut self) -> &mut dyn FallibleTypeFolder<I, Error = Self::Error>
fn as_dyn(&mut self) -> &mut dyn FallibleTypeFolder<I, Error = Self::Error>
Creates a
dyn
value from this folder. Unfortunately, this
must be added manually to each impl of FallibleTypeFolder; it
permits the default implements below to create a
&mut dyn FallibleTypeFolder
from Self
without knowing what
Self
is (by invoking this method). Effectively, this limits
impls of FallibleTypeFolder
to types for which we are able to
create a dyn value (i.e., not [T]
types).source§fn try_fold_free_placeholder_ty(
&mut self,
universe: PlaceholderIndex,
_outer_binder: DebruijnIndex,
) -> Fallible<Ty<I>>
fn try_fold_free_placeholder_ty( &mut self, universe: PlaceholderIndex, _outer_binder: DebruijnIndex, ) -> Fallible<Ty<I>>
Invoked for each occurrence of a placeholder type; these are
used when we instantiate binders universally. Returns a type
to use instead, which should be suitably shifted to account
for
binders
. Read moresource§fn try_fold_free_placeholder_const(
&mut self,
ty: Ty<I>,
universe: PlaceholderIndex,
_outer_binder: DebruijnIndex,
) -> Fallible<Const<I>>
fn try_fold_free_placeholder_const( &mut self, ty: Ty<I>, universe: PlaceholderIndex, _outer_binder: DebruijnIndex, ) -> Fallible<Const<I>>
As with
try_fold_free_placeholder_ty
, but for constants.source§fn try_fold_free_placeholder_lifetime(
&mut self,
ui: PlaceholderIndex,
_outer_binder: DebruijnIndex,
) -> Fallible<Lifetime<I>>
fn try_fold_free_placeholder_lifetime( &mut self, ui: PlaceholderIndex, _outer_binder: DebruijnIndex, ) -> Fallible<Lifetime<I>>
As with
try_fold_free_placeholder_ty
, but for lifetimes.source§fn try_fold_inference_ty(
&mut self,
var: InferenceVar,
kind: TyVariableKind,
_outer_binder: DebruijnIndex,
) -> Fallible<Ty<I>>
fn try_fold_inference_ty( &mut self, var: InferenceVar, kind: TyVariableKind, _outer_binder: DebruijnIndex, ) -> Fallible<Ty<I>>
Invoked for each occurrence of a inference type; these are
used when we instantiate binders universally. Returns a type
to use instead, which should be suitably shifted to account
for
binders
. Read moresource§fn try_fold_inference_const(
&mut self,
ty: Ty<I>,
var: InferenceVar,
_outer_binder: DebruijnIndex,
) -> Fallible<Const<I>>
fn try_fold_inference_const( &mut self, ty: Ty<I>, var: InferenceVar, _outer_binder: DebruijnIndex, ) -> Fallible<Const<I>>
As with
try_fold_inference_ty
, but for constants.source§fn try_fold_inference_lifetime(
&mut self,
var: InferenceVar,
outer_binder: DebruijnIndex,
) -> Fallible<Lifetime<I>>
fn try_fold_inference_lifetime( &mut self, var: InferenceVar, outer_binder: DebruijnIndex, ) -> Fallible<Lifetime<I>>
As with
try_fold_inference_ty
, but for lifetimes.source§fn forbid_free_vars(&self) -> bool
fn forbid_free_vars(&self) -> bool
If overridden to return true, then folding will panic if a
free variable is encountered. This should be done if free
type/lifetime variables are not expected.
source§fn try_fold_ty(
&mut self,
ty: Ty<I>,
outer_binder: DebruijnIndex,
) -> Result<Ty<I>, Self::Error>
fn try_fold_ty( &mut self, ty: Ty<I>, outer_binder: DebruijnIndex, ) -> Result<Ty<I>, Self::Error>
Top-level callback: invoked for each
Ty<I>
that is
encountered when folding. By default, invokes
try_super_fold_with
, which will in turn invoke the more
specialized folding methods below, like try_fold_free_var_ty
.source§fn try_fold_lifetime(
&mut self,
lifetime: Lifetime<I>,
outer_binder: DebruijnIndex,
) -> Result<Lifetime<I>, Self::Error>
fn try_fold_lifetime( &mut self, lifetime: Lifetime<I>, outer_binder: DebruijnIndex, ) -> Result<Lifetime<I>, Self::Error>
Top-level callback: invoked for each
Lifetime<I>
that is
encountered when folding. By default, invokes
try_super_fold_with
, which will in turn invoke the more
specialized folding methods below, like try_fold_free_var_lifetime
.source§fn try_fold_const(
&mut self,
constant: Const<I>,
outer_binder: DebruijnIndex,
) -> Result<Const<I>, Self::Error>
fn try_fold_const( &mut self, constant: Const<I>, outer_binder: DebruijnIndex, ) -> Result<Const<I>, Self::Error>
Top-level callback: invoked for each
Const<I>
that is
encountered when folding. By default, invokes
try_super_fold_with
, which will in turn invoke the more
specialized folding methods below, like try_fold_free_var_const
.source§fn try_fold_program_clause(
&mut self,
clause: ProgramClause<I>,
outer_binder: DebruijnIndex,
) -> Result<ProgramClause<I>, Self::Error>
fn try_fold_program_clause( &mut self, clause: ProgramClause<I>, outer_binder: DebruijnIndex, ) -> Result<ProgramClause<I>, Self::Error>
Invoked for every program clause. By default, recursively folds the goals contents.
source§fn try_fold_goal(
&mut self,
goal: Goal<I>,
outer_binder: DebruijnIndex,
) -> Result<Goal<I>, Self::Error>
fn try_fold_goal( &mut self, goal: Goal<I>, outer_binder: DebruijnIndex, ) -> Result<Goal<I>, Self::Error>
Invoked for every goal. By default, recursively folds the goals contents.
source§fn try_fold_free_var_ty(
&mut self,
bound_var: BoundVar,
outer_binder: DebruijnIndex,
) -> Result<Ty<I>, Self::Error>
fn try_fold_free_var_ty( &mut self, bound_var: BoundVar, outer_binder: DebruijnIndex, ) -> Result<Ty<I>, Self::Error>
Invoked for
TyKind::BoundVar
instances that are not bound
within the type being folded over: Read moresource§fn try_fold_free_var_lifetime(
&mut self,
bound_var: BoundVar,
outer_binder: DebruijnIndex,
) -> Result<Lifetime<I>, Self::Error>
fn try_fold_free_var_lifetime( &mut self, bound_var: BoundVar, outer_binder: DebruijnIndex, ) -> Result<Lifetime<I>, Self::Error>
As
try_fold_free_var_ty
, but for lifetimes.source§fn try_fold_free_var_const(
&mut self,
ty: Ty<I>,
bound_var: BoundVar,
outer_binder: DebruijnIndex,
) -> Result<Const<I>, Self::Error>
fn try_fold_free_var_const( &mut self, ty: Ty<I>, bound_var: BoundVar, outer_binder: DebruijnIndex, ) -> Result<Const<I>, Self::Error>
As
try_fold_free_var_ty
, but for constants.source§fn forbid_free_placeholders(&self) -> bool
fn forbid_free_placeholders(&self) -> bool
If overridden to return true, we will panic when a free
placeholder type/lifetime/const is encountered.
source§fn forbid_inference_vars(&self) -> bool
fn forbid_inference_vars(&self) -> bool
If overridden to return true, inference variables will trigger
panics when folded. Used when inference variables are
unexpected.
Auto Trait Implementations§
impl<'u, 't, I> Freeze for OccursCheck<'u, 't, I>
impl<'u, 't, I> !RefUnwindSafe for OccursCheck<'u, 't, I>
impl<'u, 't, I> !Send for OccursCheck<'u, 't, I>
impl<'u, 't, I> !Sync for OccursCheck<'u, 't, I>
impl<'u, 't, I> Unpin for OccursCheck<'u, 't, I>where
I: Unpin,
impl<'u, 't, I> !UnwindSafe for OccursCheck<'u, 't, I>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<T> Cast for T
impl<T> Cast for T
source§fn cast<U>(self, interner: <U as HasInterner>::Interner) -> Uwhere
Self: CastTo<U>,
U: HasInterner,
fn cast<U>(self, interner: <U as HasInterner>::Interner) -> Uwhere
Self: CastTo<U>,
U: HasInterner,
Cast a value to type
U
using CastTo
.