Enum GraphResult 

pub enum GraphResult {
    VisitOrder,
    Reached,
    CostTable,
    Distance,
    Path,
}

What a graph helper answers.

Variants

VisitOrder

Vec[T] — every state reached, in the order the walk reached it.

Reached

Set[T] — every state reached, without an order.

CostTable

Map[T, Int] — the least cost from the start to each reachable state. A state that is not reachable is simply absent, which is why this needs no Option.

Distance

Option[Int] — the cost of the cheapest path to a goal, or None when no goal is reachable. “Unreachable” is an ordinary outcome of a search, not a fault, and a sentinel -1 would be a number nobody wrote.

Path

Option[Vec[T]] — the route to the goal a search stopped at, from the start to the goal inclusive, or None when no goal is reachable.

The Option is Distance’s, for the same reason: a helper that takes a goal may not find one. An empty Vec could not stand for that, because a route that was found always holds at least its own start — so “no route” and “a route of nothing” would be the same value.

Trait Implementations

impl Clone for GraphResult

fn clone(&self) -> GraphResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for GraphResult

impl Debug for GraphResult

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

Formats the value using the given formatter.

impl Eq for GraphResult

impl PartialEq for GraphResult

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for GraphResult