[][src]Struct rustc_data_structures::transitive_relation::TransitiveRelation

pub struct TransitiveRelation<T: Clone + Debug + Eq + Hash> {
    elements: Vec<T>,
    map: FxHashMap<T, Index>,
    edges: Vec<Edge>,
    closure: Lock<Option<BitMatrix<usize, usize>>>,
}
🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Fields

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Methods

impl<T: Clone + Debug + Eq + Hash> TransitiveRelation<T>
[src]

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Applies the (partial) function to each edge and returns a new relation. If f returns None for any end-point, returns None.

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Indicate that a < b (where < is this relation)

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Check whether a < target (transitively)

Important traits for Vec<u8>

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Thinking of x R y as an edge x -> y in a graph, this returns all things reachable from a.

Really this probably ought to be impl Iterator<Item=&T>, but I'm too lazy to make that work, and -- given the caching strategy -- it'd be a touch tricky anyhow.

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Picks what I am referring to as the "postdominating" upper-bound for a and b. This is usually the least upper bound, but in cases where there is no single least upper bound, it is the "mutual immediate postdominator", if you imagine a graph where a < b means a -> b.

This function is needed because region inference currently requires that we produce a single "UB", and there is no best choice for the LUB. Rather than pick arbitrarily, I pick a less good, but predictable choice. This should help ensure that region inference yields predictable results (though it itself is not fully sufficient).

Examples are probably clearer than any prose I could write (there are corresponding tests below, btw). In each case, the query is postdom_upper_bound(a, b):

// returns Some(x), which is also LUB
a -> a1 -> x
           ^
           |
b -> b1 ---+

// returns Some(x), which is not LUB (there is none)
// diagonal edges run left-to-right
a -> a1 -> x
  \/       ^
  /\       |
b -> b1 ---+

// returns None
a -> a1
b -> b1

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Viewing the relation as a graph, computes the "mutual immediate postdominator" of a set of points (if one exists). See postdom_upper_bound for details.

Important traits for Vec<u8>

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Returns the set of bounds X such that:

  • a < X and b < X
  • there is no Y != X such that a < Y and Y < X
    • except for the case where X < a (i.e., a strongly connected component in the graph). In that case, the smallest representative of the SCC is returned (as determined by the internal indices).

Note that this set can, in principle, have any size.

Important traits for Vec<u8>

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Given an element A, returns the maximal set {B} of elements B such that

  • A != B
  • A R B is true
  • for each i, j: B[i] R B[j] does not hold

The intuition is that this moves "one step up" through a lattice (where the relation is encoding the <= relation for the lattice). So e.g. if the relation is -> and we have

a -> b -> d -> f
|              ^
+--> c -> e ---+

then parents(a) returns [b, c]. The postdom_parent function would further reduce this to just f.

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

A "best" parent in some sense. See parents and postdom_upper_bound for more details.

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Trait Implementations

impl<T: Clone + Clone + Debug + Eq + Hash> Clone for TransitiveRelation<T>
[src]

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

impl<T: Debug + Clone + Debug + Eq + Hash> Debug for TransitiveRelation<T>
[src]

Formats the value using the given formatter. Read more

impl<T> Encodable for TransitiveRelation<T> where
    T: Clone + Encodable + Debug + Eq + Hash + Clone
[src]

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

impl<T> Decodable for TransitiveRelation<T> where
    T: Clone + Decodable + Debug + Eq + Hash + Clone
[src]

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

impl<CTX, T> HashStable<CTX> for TransitiveRelation<T> where
    T: HashStable<CTX> + Eq + Debug + Clone + Hash
[src]

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Auto Trait Implementations

impl<T> Send for TransitiveRelation<T> where
    T: Send

impl<T> !Sync for TransitiveRelation<T>

Blanket Implementations

impl<T> Erased for T
[src]

impl<T> Send for T where
    T: ?Sized
[src]

impl<T> Sync for T where
    T: ?Sized
[src]

impl<T> ToOwned for T where
    T: Clone
[src]

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

impl<T> From for T
[src]

Performs the conversion.

impl<T, U> Into for T where
    U: From<T>, 
[src]

Performs the conversion.

impl<T, U> TryFrom for T where
    T: From<U>, 
[src]

🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

🔬 This is a nightly-only experimental API. (try_from)

Performs the conversion.

impl<T> Borrow for T where
    T: ?Sized
[src]

Important traits for &'a mut R

Immutably borrows from an owned value. Read more

impl<T, U> TryInto for T where
    U: TryFrom<T>, 
[src]

🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

🔬 This is a nightly-only experimental API. (try_from)

Performs the conversion.

impl<T> BorrowMut for T where
    T: ?Sized
[src]

Important traits for &'a mut R

Mutably borrows from an owned value. Read more

impl<T> Any for T where
    T: 'static + ?Sized
[src]

🔬 This is a nightly-only experimental API. (get_type_id)

this method will likely be replaced by an associated static

Gets the TypeId of self. Read more

impl<T> Encodable for T where
    T: UseSpecializedEncodable + ?Sized
[src]

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

impl<T> Decodable for T where
    T: UseSpecializedDecodable
[src]

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

impl<E> SpecializationError for E
[src]

🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

Create an error for a missing method specialization. Defaults to panicking with type, trait & method names. S is the encoder/decoder state type, T is the type being encoded/decoded, and the arguments are the names of the trait and method that should've been overridden. Read more

impl<T> Erased for T