com.google.javascript.rhino

Interface PMap<K,V>

All Known Implementing Classes:

HamtPMap

public interface PMap<K,V>

A minimal interface for null-hostile, persistent immutable maps.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	PMap.BiFunction<A,B,C> See java.util.function.BiFunction.
static interface	PMap.BiPredicate<A,B> See java.util.function.BiPredicate.

Method Summary

Modifier and Type	Method and Description
boolean	equivalent(PMap<K,V> that, PMap.BiPredicate<V,V> equivalence) Checks equality recursively based on the given equivalence.
V	get(K key) Retrieves the given key from the map, or returns null if it is not present.
boolean	isEmpty() Returns whether this map is empty.
PMap<K,V>	minus(K key) Returns a new map with the given key removed.
PMap<K,V>	plus(K key, V value) Returns a new map with the given key-value pair added.
PMap<K,V>	reconcile(PMap<K,V> that, PMap.BiFunction<V,V,V> joiner) Performs a reconcile operation.
java.lang.Iterable<V>	values() Returns an iterable for the values in this map.

Method Detail

isEmpty

boolean isEmpty()

Returns whether this map is empty.

values

java.lang.Iterable<V> values()

Returns an iterable for the values in this map.

get

@Nullable
V get(K key)

Retrieves the given key from the map, or returns null if it is not present.

plus

PMap<K,V> plus(K key,
               V value)

Returns a new map with the given key-value pair added. If the value is already present, then this same map will be returned.

minus

PMap<K,V> minus(K key)

Returns a new map with the given key removed. If the key was not present in the first place, then this same map will be returned.

reconcile

PMap<K,V> reconcile(PMap<K,V> that,
                    PMap.BiFunction<V,V,V> joiner)

Performs a reconcile operation. The joiner is called for all conflicting (based on Object#equals) values between the two maps, or if a key is missing from one map. If both maps have equal values then that value will be added directly to the result without calling the joiner. If the joiner returns null, then the entry is removed. The first argument to the joined always comes from 'this' map, and the second is always from 'that'. Note that that map must be the same implementation.

equivalent

boolean equivalent(PMap<K,V> that,
                   PMap.BiPredicate<V,V> equivalence)

Checks equality recursively based on the given equivalence. Short-circuits as soon as a 'false' result is found, or if a key in one map is missing from the other. The equivalence will only be called on two non-null values. Note that that map must be the same implementation. Note that the equivalence MUST be reflective (i.e. equivalence.test(x, x) == true).