BishBosh.State.InstancesByPosition

AUTHOR

Dr. Alistair Ward

DESCRIPTION

Records the number of times each position has been encountered since the last unrepeatable move.

Types

Type-synonyms

Constants

leastCyclicPlies :: NPlies

The smallest number of repeatable plies (applied by alternating players) required to form a cycle.

Data-types

data InstancesByPosition position

Wrap the type, so that class-instances can be hung from it.

Instances

Eq position => Eq (InstancesByPosition position)

Defined in BishBosh.State.InstancesByPosition

Methods

(==) :: InstancesByPosition position -> InstancesByPosition position -> Bool

(/=) :: InstancesByPosition position -> InstancesByPosition position -> Bool

NFData position => NFData (InstancesByPosition position)

Defined in BishBosh.State.InstancesByPosition

Methods

rnf :: InstancesByPosition position -> ()

(Ord position, ReflectableOnX position) => ReflectableOnX (InstancesByPosition position)

Defined in BishBosh.State.InstancesByPosition

Methods

reflectOnX :: InstancesByPosition position -> InstancesByPosition position

Functions

countConsecutiveRepeatablePlies :: InstancesByPosition position -> NPlies

• Count the total number of consecutive repeatable plies amongst recent moves.
• This is equivalent to the number of entries in the map, since adding a non-repeatable move triggers a purge.

countPositionRepetitions :: InstancesByPosition position -> NPositions

Count the total number of repetitions of positions.

getNDistinctPositions :: InstancesByPosition position -> NPositions

The number of distinct positions.

findMaximumInstances :: InstancesByPosition position -> NPositions

• Find the maximum number of times any one position has already been visited.
• CAVEAT: only those positions that can still be reached are considered.

Constructors

mkInstancesByPosition

Arguments

:: (Foldable foldable, Ord position)

=> (a -> position)

Position-constructor.

-> foldable a

Data from which to construct positions.

-> InstancesByPosition position

Construct from repeatable data.

mkSingleton :: position -> InstancesByPosition position

Constructor.

Mutators

insertPosition

Arguments

:: Ord position

=> Bool

Whether the turn which led to the specified position, was repeatable.

-> position

-> Transformation position

Insert a position into the collection.

deletePosition :: Ord position => position -> Transformation position

Remove a position from the collection, as required to implement rollback.

Predicates

anyInstancesByPosition :: (NPositions -> Bool) -> InstancesByPosition position -> Bool

Predicate: apply the specified predicate to the map.