org.organicdesign.fp.collections

Interface UnmodMap<K,V>

All Superinterfaces:

Iterable<UnmodMap.UnEntry<K,V>>, Map<K,V>, Sized, Transformable<UnmodMap.UnEntry<K,V>>, UnmodIterable<UnmodMap.UnEntry<K,V>>

All Known Subinterfaces:

ImMap<K,V>, ImMapTrans<K,V>, ImSortedMap<K,V>, ImUnsortedMap<K,V>, MutableUnsortedMap<K,V>, UnmodSortedMap<K,V>

All Known Implementing Classes:

FunctionUtils.UnmodifiableMap, FunctionUtils.UnmodifiableSortedMap, PersistentHashMap, PersistentHashMap.MutableHashMap, PersistentTreeMap, UnmodMap.AbstractUnmodMap

public interface UnmodMap<K,V>
extends Map<K,V>, UnmodIterable<UnmodMap.UnEntry<K,V>>, Sized

An unmodifiable map. This cannot extend Collection because the remove() method would then be inherited from both Collection and Map and Collection.remove() returns a boolean while Map.remove() returns a V (the type of the value in the key/value pair). Maybe an UnmodSizedIterable is called for?

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	UnmodMap.AbstractUnmodMap<K,V> Implements equals and hashCode() methods compatible with java.util.Map (which ignores order) to make defining unmod Maps easier.
static interface	UnmodMap.UnEntry<K,V> A map entry (key-value pair).

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Nested classes/interfaces inherited from interface org.organicdesign.fp.collections.UnmodIterable

UnmodIterable.AbstractUnmodIterable<T>

Method Summary

Modifier and Type	Method and Description
default void	clear() Deprecated.
default V	compute(K key, BiFunction<? super K,? super V,? extends V> remappingFunction) Deprecated.
default V	computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction) Deprecated.
default V	computeIfPresent(K key, BiFunction<? super K,? super V,? extends V> remappingFunction) Deprecated.
default boolean	containsValue(Object value) Most maps are not designed for this - the default implementation has O(n) performance.
default UnmodSet<Map.Entry<K,V>>	entrySet() Returns a view of the mappings contained in this map.
default boolean	isEmpty()
default UnmodSet<K>	keySet() Returns a view of the keys contained in this map.
default V	merge(K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction) Deprecated.
default V	put(K key, V value) Deprecated.
default void	putAll(Map<? extends K,? extends V> m) Deprecated.
default V	putIfAbsent(K key, V value) Deprecated.
default V	remove(Object key) Deprecated.
default boolean	remove(Object key, Object value) Deprecated.
default V	replace(K key, V value) Deprecated.
default boolean	replace(K key, V oldValue, V newValue) Deprecated.
default void	replaceAll(BiFunction<? super K,? super V,? extends V> function) Deprecated.
default UnmodCollection<V>	values() Deprecated.

Methods inherited from interface java.util.Map

containsKey, equals, forEach, get, getOrDefault, hashCode, size

Methods inherited from interface org.organicdesign.fp.collections.UnmodIterable

concat, drop, filter, flatMap, foldLeft, foldLeft, hash, hashCode, head, iterator, map, precat, take, takeWhile, toString

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface org.organicdesign.fp.xform.Transformable

toImList, toImMap, toImSet, toImSortedMap, toImSortedSet, toMutableList, toMutableMap, toMutableSet, toMutableSortedMap, toMutableSortedSet

Methods inherited from interface org.organicdesign.fp.collections.Sized

size

Method Detail

clear

@Deprecated
default void clear()

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

clear in interface Map<K,V>

compute

@Deprecated
default V compute(K key,
                              BiFunction<? super K,? super V,? extends V> remappingFunction)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

compute in interface Map<K,V>

computeIfAbsent

@Deprecated
default V computeIfAbsent(K key,
                                      Function<? super K,? extends V> mappingFunction)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

computeIfAbsent in interface Map<K,V>

computeIfPresent

@Deprecated
default V computeIfPresent(K key,
                                       BiFunction<? super K,? super V,? extends V> remappingFunction)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

computeIfPresent in interface Map<K,V>

containsValue

default boolean containsValue(Object value)

Most maps are not designed for this - the default implementation has O(n) performance.

Specified by:

containsValue in interface Map<K,V>

entrySet

default UnmodSet<Map.Entry<K,V>> entrySet()

Returns a view of the mappings contained in this map. The set will contain UnmodMap.UnEntry items, but that return signature is illegal in Java, so you'll just have to remember. An UnmodMap is iterable, so this method is probably not nearly as useful as it once was.

Specified by:

entrySet in interface Map<K,V>

isEmpty

default boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

keySet

default UnmodSet<K> keySet()

Returns a view of the keys contained in this map. An UnmodMap is iterable, so this method is probably not nearly as useful as it once was.

Specified by:

keySet in interface Map<K,V>

merge

@Deprecated
default V merge(K key,
                            V value,
                            BiFunction<? super V,? super V,? extends V> remappingFunction)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

merge in interface Map<K,V>

put

@Deprecated
default V put(K key,
                          V value)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

put in interface Map<K,V>

putAll

@Deprecated
default void putAll(Map<? extends K,? extends V> m)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

putAll in interface Map<K,V>

putIfAbsent

@Deprecated
default V putIfAbsent(K key,
                                  V value)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

putIfAbsent in interface Map<K,V>

remove

@Deprecated
default V remove(Object key)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

remove in interface Map<K,V>

remove

@Deprecated
default boolean remove(Object key,
                                   Object value)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

remove in interface Map<K,V>

replace

@Deprecated
default boolean replace(K key,
                                    V oldValue,
                                    V newValue)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

replace in interface Map<K,V>

replace

@Deprecated
default V replace(K key,
                              V value)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

replace in interface Map<K,V>

replaceAll

@Deprecated
default void replaceAll(BiFunction<? super K,? super V,? extends V> function)

Deprecated.

Not allowed - this is supposed to be unmodifiable

Specified by:

replaceAll in interface Map<K,V>

values

@Deprecated
default UnmodCollection<V> values()

Deprecated.

This method has been deprecated because it is impossible to implement equals() or hashCode() on the resulting collection, and calling this method is probably at least a missed opportunity, if not an outright error. Use an UnmodMap as an UnmodIterable<UnmodMap.UnEntry> instead. If you don't care about eliminating duplicate values, and want a compatible return type call:

myMap.map((UnEntry<K,V> entry) -> entry.getValue())
             .toImSet();

If you want to keep a count of duplicates, try something like this, but it has a different signature:

ImMap<V,Integer> valueCounts = myMap.foldLeft(PersistentHashMap.empty(),
                     (ImMap<V,Integer> accum, UnEntry<K,V> origEntry) -> {
                             V inVal = origEntry.getValue();
                             return accum.assoc(inVal,
                                                accum.getOrElse(inVal, 0) + 1);
                         });

You really shouldn't turn values() into a List, because a List has order and an unsorted Map is unordered by key, and especially unordered by value. On a SortedMap, List is the proper return type. java.util.HashMap.values() returns an instance of java.util.HashMap.Values which does *not* have equals() or hashCode() defined. This is because List.equals() and Set.equals() return not-equal when compared to a Collection. There is no good way to implement a reflexive equals with both of those because they are just too different. Ultimately, Collection just isn't specific enough to instantiate, but we do it anyway here for backward compatibility. We don't implement equals() or hashCode() either because the result could have duplicates. If the Map isn't sorted, the result could have random ordering.

Specified by:

values in interface Map<K,V>