Struct BoundVar

pub struct BoundVar {
    pub debruijn: DebruijnIndex,
    pub index: usize,
}

Identifies a particular bound variable within a binder. Variables are identified by the combination of a DebruijnIndex, which identifies the binder, and an index within that binder.

Consider this case:

forall<'a, 'b> { forall<'c, 'd> { ... } }

Within the ... term:

• the variable 'a have a debruijn index of 1 and index 0
• the variable 'b have a debruijn index of 1 and index 1
• the variable 'c have a debruijn index of 0 and index 0
• the variable 'd have a debruijn index of 0 and index 1

The variables 'a and 'b both have debruijn index of 1 because, counting out, they are the 2nd binder enclosing .... The indices identify the location within that binder.

The variables 'c and 'd both have debruijn index of 0 because they appear in the innermost binder enclosing the .... The indices identify the location within that binder.

Fields

debruijn: DebruijnIndex

Debruijn index, which identifies the binder.

index: usize

Index within the binder.

Implementations

impl BoundVar

pub fn new(debruijn: DebruijnIndex, index: usize) -> BoundVar

Creates a new bound variable.

pub fn to_ty<I>(self, interner: I) -> Ty<I>

where I: Interner,

Casts the bound variable to a type.

pub fn to_lifetime<I>(self, interner: I) -> Lifetime<I>

where I: Interner,

Wrap the bound variable in a lifetime.

pub fn to_const<I>(self, interner: I, ty: Ty<I>) -> Const<I>

where I: Interner,

Wraps the bound variable in a constant.

pub fn bound_within(self, outer_binder: DebruijnIndex) -> bool

True if this variable is bound within the amount innermost binders.

pub fn shifted_in(self) -> BoundVar

Adjusts the debruijn index (see DebruijnIndex::shifted_in).

pub fn shifted_in_from(self, outer_binder: DebruijnIndex) -> BoundVar

Adjusts the debruijn index (see DebruijnIndex::shifted_in).

pub fn shifted_out(self) -> Option<BoundVar>

Adjusts the debruijn index (see DebruijnIndex::shifted_in).

pub fn shifted_out_to(self, outer_binder: DebruijnIndex) -> Option<BoundVar>

Adjusts the debruijn index (see DebruijnIndex::shifted_in).

pub fn index_if_innermost(self) -> Option<usize>

Return the index of the bound variable, but only if it is bound at the innermost binder. Otherwise, returns None.

pub fn index_if_bound_at(self, debruijn: DebruijnIndex) -> Option<usize>

Return the index of the bound variable, but only if it is bound at the innermost binder. Otherwise, returns None.

Trait Implementations

impl Clone for BoundVar

fn clone(&self) -> BoundVar

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BoundVar

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

Formats the value using the given formatter.

impl Hash for BoundVar

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl HirDisplay for BoundVar

fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError>

fn into_displayable<'a>( &'a self, db: &'a dyn HirDatabase, max_size: Option<usize>, limited_size: Option<usize>, omit_verbose_types: bool, display_target: DisplayTarget, closure_style: ClosureStyle, show_container_bounds: bool, ) -> HirDisplayWrapper<'a, Self>

where Self: Sized,

Returns a Displayable type that is human-readable.

fn display<'a>( &'a self, db: &'a dyn HirDatabase, edition: Edition, ) -> HirDisplayWrapper<'a, Self>

where Self: Sized,

Returns a Displayable type that is human-readable. Use this for showing types to the user (e.g. diagnostics)

fn display_truncated<'a>( &'a self, db: &'a dyn HirDatabase, max_size: Option<usize>, edition: Edition, ) -> HirDisplayWrapper<'a, Self>

where Self: Sized,

Returns a Displayable type that is human-readable and tries to be succinct. Use this for showing types to the user where space is constrained (e.g. doc popups)

fn display_limited<'a>( &'a self, db: &'a dyn HirDatabase, limited_size: Option<usize>, edition: Edition, ) -> HirDisplayWrapper<'a, Self>

where Self: Sized,

Returns a Displayable type that is human-readable and tries to limit the number of items inside. Use this for showing definitions which may contain too many items, like trait, struct, enum

fn display_source_code<'a>( &'a self, db: &'a dyn HirDatabase, module_id: ModuleId, allow_opaque: bool, ) -> Result<String, DisplaySourceCodeError>

Returns a String representation of self that can be inserted into the given module. Use this when generating code (e.g. assists)

fn display_test<'a>( &'a self, db: &'a dyn HirDatabase, ) -> HirDisplayWrapper<'a, Self>

where Self: Sized,

Returns a String representation of self for test purposes

fn display_with_container_bounds<'a>( &'a self, db: &'a dyn HirDatabase, show_container_bounds: bool, edition: Edition, ) -> HirDisplayWrapper<'a, Self>

where Self: Sized,

Returns a String representation of self that shows the constraint from the container for functions

impl Ord for BoundVar

fn cmp(&self, other: &BoundVar) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for BoundVar

fn eq(&self, other: &BoundVar) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for BoundVar

fn partial_cmp(&self, other: &BoundVar) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for BoundVar

impl Eq for BoundVar

impl StructuralPartialEq for BoundVar