Struct chalk_ir::Binders [−][src]
pub struct Binders<T: HasInterner> { pub binders: VariableKinds<T::Interner>, // some fields omitted }
Expand description
Indicates that the value
is universally quantified over N
parameters of the given kinds, where N == self.binders.len()
. A
variable with depth i < N
refers to the value at
self.binders[i]
. Variables with depth >= N
are free.
(IOW, we use deBruijn indices, where binders are introduced in reverse order
of self.binders
.)
Fields
binders: VariableKinds<T::Interner>
The binders that quantify over the value.
Implementations
As with WhereClause::into_well_formed_goal
, but for a
quantified where clause. For example, forall<T> { Implemented(T: Trait)}
would map to forall<T> { WellFormed(T: Trait) }
.
As with WhereClause::into_from_env_goal
, but mapped over any
binders. For example, forall<T> { Implemented(T: Trait)}
would map to forall<T> { FromEnv(T: Trait) }
.
Create new binders.
Wraps the given value in a binder without variables, i.e. for<> (value)
. Since our deBruijn indices count binders, not variables, this
is sometimes useful.
Skips the binder and returns the “bound” value. This is a
risky thing to do because it’s easy to get confused about
De Bruijn indices and the like. skip_binder
is only valid
when you are either extracting data that has nothing to
do with bound vars, or you are being very careful about
your depth accounting.
Some examples where skip_binder
is reasonable:
- extracting the
TraitId
from a TraitRef; - checking if there are any fields in a StructDatum
Skips the binder and returns the “bound” value as well as the skipped free variables. This
is just as risky as [skip_binders
].
Converts &Binders<T>
to Binders<&T>
. Produces new Binders
with cloned quantifiers containing a reference to the original
value, leaving the original in place.
Maps the binders by applying a function.
pub fn filter_map<U, OP>(self, op: OP) -> Option<Binders<U>> where
OP: FnOnce(T) -> Option<U>,
U: HasInterner<Interner = T::Interner>,
[src]
pub fn filter_map<U, OP>(self, op: OP) -> Option<Binders<U>> where
OP: FnOnce(T) -> Option<U>,
U: HasInterner<Interner = T::Interner>,
[src]Transforms the inner value according to the given function; returns
None
if the function returns None
.
Maps a function taking Binders<&T>
over &Binders<T>
.
Creates a Substitution
containing bound vars such that applying this
substitution will not change the value, i.e. ^0.0, ^0.1, ^0.2
and so
on.
Creates a fresh binders that contains a single type variable. The result of the closure will be embedded in this binder. Note that you should be careful with what you return from the closure to account for the binder that will be added.
XXX FIXME – this is potentially a pretty footgun-y function.
impl<T, I> Binders<Binders<T>> where
T: Fold<I> + HasInterner<Interner = I>,
T::Result: HasInterner<Interner = I>,
I: Interner,
[src]
impl<T, I> Binders<Binders<T>> where
T: Fold<I> + HasInterner<Interner = I>,
T::Result: HasInterner<Interner = I>,
I: Interner,
[src]This turns two levels of binders (for<A> for<B>
) into one level (for<A, B>
).
pub fn substitute(
self,
interner: &I,
parameters: &impl AsParameters<I> + ?Sized
) -> T::Result
[src]
pub fn substitute(
self,
interner: &I,
parameters: &impl AsParameters<I> + ?Sized
) -> T::Result
[src]Substitute parameters
for the variables introduced by these
binders. So if the binders represent (e.g.) <X, Y> { T }
and
parameters is the slice [A, B]
, then returns [X => A, Y => B] T
.
Trait Implementations
fn cast_to(
self,
_interner: &<QuantifiedWhereClause<I> as HasInterner>::Interner
) -> QuantifiedWhereClause<I>
[src]
fn cast_to(
self,
_interner: &<QuantifiedWhereClause<I> as HasInterner>::Interner
) -> QuantifiedWhereClause<I>
[src]Cast a value to type T
.
impl<I, T> CastTo<ProgramClause<I>> for Binders<T> where
I: Interner,
T: HasInterner<Interner = I> + CastTo<DomainGoal<I>>,
[src]
impl<I, T> CastTo<ProgramClause<I>> for Binders<T> where
I: Interner,
T: HasInterner<Interner = I> + CastTo<DomainGoal<I>>,
[src]Cast a value to type T
.
impl<T, I: Interner> Fold<I> for Binders<T> where
T: HasInterner<Interner = I> + Fold<I>,
<T as Fold<I>>::Result: HasInterner<Interner = I>,
I: Interner,
[src]
impl<T, I: Interner> Fold<I> for Binders<T> where
T: HasInterner<Interner = I> + Fold<I>,
<T as Fold<I>>::Result: HasInterner<Interner = I>,
I: Interner,
[src]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
impl<V, U> IntoIterator for Binders<V> where
V: HasInterner + IntoIterator<Item = U>,
U: HasInterner<Interner = V::Interner>,
[src]
impl<V, U> IntoIterator for Binders<V> where
V: HasInterner + IntoIterator<Item = U>,
U: HasInterner<Interner = V::Interner>,
[src]Allows iterating over a Binders<Vec
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<T: HasInterner + Copy> Copy for Binders<T> where
<T::Interner as Interner>::InternedVariableKinds: Copy,
[src]Auto Trait Implementations
impl<T> RefUnwindSafe for Binders<T> where
T: RefUnwindSafe,
<<T as HasInterner>::Interner as Interner>::InternedVariableKinds: RefUnwindSafe,
impl<T> Send for Binders<T> where
T: Send,
<<T as HasInterner>::Interner as Interner>::InternedVariableKinds: Send,
impl<T> Sync for Binders<T> where
T: Sync,
<<T as HasInterner>::Interner as Interner>::InternedVariableKinds: Sync,
impl<T> Unpin for Binders<T> where
T: Unpin,
<<T as HasInterner>::Interner as Interner>::InternedVariableKinds: Unpin,
impl<T> UnwindSafe for Binders<T> where
T: UnwindSafe,
<<T as HasInterner>::Interner as Interner>::InternedVariableKinds: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more
Cast a value to type U
using CastTo
.
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.