Struct chalk_ir::UniverseIndex [−][src]
pub struct UniverseIndex {
pub counter: usize,
}
Expand description
An universe index is how a universally quantified parameter is
represented when it’s binder is moved into the environment.
An example chain of transformations would be:
forall<T> { Goal(T) }
(syntactical representation)
forall { Goal(?0) }
(used a DeBruijn index)
Goal(!U1)
(the quantifier was moved to the environment and replaced with a universe index)
See https://rustc-dev-guide.rust-lang.org/borrow_check/region_inference.html#placeholders-and-universes for more.
Fields
counter: usize
The counter for the universe index, starts with 0.
Implementations
Root universe index (0).
Root universe index (0).
Whether one universe can “see” another.
Increases the index counter.
Trait Implementations
type Result = Self
type Result = Self
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
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
This method tests for !=
.
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
fn visit_with<'i, B>(
&self,
_visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
_outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
fn visit_with<'i, B>(
&self,
_visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
_outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
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
Auto Trait Implementations
impl RefUnwindSafe for UniverseIndex
impl Send for UniverseIndex
impl Sync for UniverseIndex
impl Unpin for UniverseIndex
impl UnwindSafe for UniverseIndex
Blanket Implementations
Mutably borrows from an owned value. Read more
Cast a value to type U
using CastTo
.
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.