it.unimi.dsi.fastutil.objects.Object2IntMap Maven / Gradle / Ivy
Show all versions of fastutil-core Show documentation
/*
* Copyright (C) 2002-2022 Sebastiano Vigna
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package it.unimi.dsi.fastutil.objects;
import it.unimi.dsi.fastutil.ints.IntCollection;
import java.util.function.Consumer;
import java.util.Map;
/** A type-specific {@link Map}; provides some additional methods that use polymorphism to avoid (un)boxing, and handling of a default return value.
*
* Besides extending the corresponding type-specific {@linkplain it.unimi.dsi.fastutil.Function function}, this interface strengthens {@link Map#entrySet()},
* {@link #keySet()} and {@link #values()}. Moreover, a number of methods, such as {@link #size()}, {@link #defaultReturnValue()}, etc., are un-defaulted
* as their function default do not make sense for a map.
* Maps returning entry sets of type {@link FastEntrySet} support also fast iteration.
*
*
A submap or subset may or may not have an
* independent default return value (which however must be initialized to the
* default return value of the originator).
*
* @see Map
*/
public interface Object2IntMap extends Object2IntFunction , Map {
/** An entry set providing fast iteration.
*
* In some cases (e.g., hash-based classes) iteration over an entry set requires the creation
* of a large number of {@link java.util.Map.Entry} objects. Some {@code fastutil}
* maps might return {@linkplain Map#entrySet() entry set} objects of type {@code FastEntrySet}: in this case, {@link #fastIterator() fastIterator()}
* will return an iterator that is guaranteed not to create a large number of objects, possibly
* by returning always the same entry (of course, mutated), and {@link #fastForEach(Consumer)} will apply
* the provided consumer to all elements of the entry set, which might be represented
* always by the same entry (of course, mutated).
*/
interface FastEntrySet extends ObjectSet > {
/** Returns a fast iterator over this entry set; the iterator might return always the same entry instance, suitably mutated.
*
* @return a fast iterator over this entry set; the iterator might return always the same {@link java.util.Map.Entry} instance, suitably mutated.
*/
ObjectIterator > fastIterator();
/** Iterates quickly over this entry set; the iteration might happen always on the same entry instance, suitably mutated.
*
* This default implementation just delegates to {@link #forEach(Consumer)}.
*
* @param consumer a consumer that will by applied to the entries of this set; the entries might be represented
* by the same entry instance, suitably mutated.
* @since 8.1.0
*/
default void fastForEach(final Consumer > consumer) {
forEach(consumer);
}
}
/**
* Returns the number of key/value mappings in this map. If the
* map contains more than {@link Integer#MAX_VALUE} elements, returns {@link Integer#MAX_VALUE}.
*
* @return the number of key-value mappings in this map.
* @see it.unimi.dsi.fastutil.Size64
*/
@Override
int size();
/** Removes all of the mappings from this map (optional operation).
* The map will be empty after this call returns.
*
* @throws UnsupportedOperationException if the {@link #clear()} operation is not supported by this map
*/
@Override
default void clear() { throw new UnsupportedOperationException(); }
/** Sets the default return value (optional operation).
*
* This value must be returned by type-specific versions of {@code get()},
* {@code put()} and {@code remove()} to denote that the map does not contain
* the specified key. It must be 0/{@code false} by default.
*
* @param rv the new default return value.
* @see #defaultReturnValue()
*/
@Override
void defaultReturnValue(int rv);
/** Gets the default return value.
*
* @return the current default return value.
*/
@Override
int defaultReturnValue();
/** Returns a type-specific set view of the mappings contained in this map.
*
*
This method is necessary because there is no inheritance along
* type parameters: it is thus impossible to strengthen {@link Map#entrySet()}
* so that it returns an {@link it.unimi.dsi.fastutil.objects.ObjectSet}
* of type-specific entries (the latter makes it possible to
* access keys and values with type-specific methods).
*
* @return a type-specific set view of the mappings contained in this map.
* @see Map#entrySet()
*/
ObjectSet > object2IntEntrySet();
/** Returns a set view of the mappings contained in this map.
* @apiNote Note that this specification strengthens the one given in {@link Map#entrySet()}.
*
* @return a set view of the mappings contained in this map.
* @see Map#entrySet()
* @deprecated Please use the corresponding type-specific method instead.
*/
@Deprecated
@Override
@SuppressWarnings({ "unchecked", "rawtypes" })
default ObjectSet> entrySet() {
return (ObjectSet)object2IntEntrySet();
}
/** {@inheritDoc}
* This default implementation just delegates to the corresponding type-specific–{@linkplain it.unimi.dsi.fastutil.Function function} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer put(final K key, final Integer value) {
return Object2IntFunction.super.put(key, value);
}
/** {@inheritDoc}
*
This default implementation just delegates to the corresponding type-specific–{@linkplain it.unimi.dsi.fastutil.Function function} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer get(final Object key) {
return Object2IntFunction.super.get(key);
}
/** {@inheritDoc}
*
This default implementation just delegates to the corresponding type-specific–{@linkplain it.unimi.dsi.fastutil.Function function} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer remove(final Object key) {
return Object2IntFunction.super.remove(key);
}
/** {@inheritDoc}
* @apiNote Note that this specification strengthens the one given in {@link Map#keySet()}.
* @return a set view of the keys contained in this map.
* @see Map#keySet()
*/
@Override
ObjectSet keySet();
/** {@inheritDoc}
* @apiNote Note that this specification strengthens the one given in {@link Map#values()}.
* @return a set view of the values contained in this map.
* @see Map#values()
*/
@Override
IntCollection values();
/** Returns true if this function contains a mapping for the specified key.
*
* @param key the key.
* @return true if this function associates a value to {@code key}.
* @see Map#containsKey(Object)
*/
@Override
boolean containsKey(Object key);
/** Returns {@code true} if this map maps one or more keys to the specified value.
* @see Map#containsValue(Object)
*/
boolean containsValue(int value);
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default boolean containsValue(final Object value) {
return value == null ? false : containsValue(((Integer)(value)).intValue());
}
// Defaultable methods
@Override
default void forEach(final java.util.function.BiConsumer consumer) {
final ObjectSet > entrySet = object2IntEntrySet();
final Consumer > wrappingConsumer = (entry) -> consumer.accept((entry.getKey()), Integer.valueOf(entry.getIntValue()));
if (entrySet instanceof FastEntrySet) {
((FastEntrySet )entrySet).fastForEach(wrappingConsumer);
} else {
entrySet.forEach(wrappingConsumer);
}
}
/** Returns the value to which the specified key is mapped, or the {@code defaultValue} if this
* map contains no mapping for the key.
*
* @param key the key.
* @param defaultValue the default mapping of the key.
*
* @return the value to which the specified key is mapped, or the {@code defaultValue} if this map contains no mapping for the key.
*
* @see java.util.Map#getOrDefault(Object, Object)
* @since 8.0.0
*/
@Override
default int getOrDefault(final Object key, final int defaultValue) {
final int v;
return ((v = getInt(key)) != defaultReturnValue() || containsKey(key)) ? v : defaultValue;
}
/** {@inheritDoc}
* This default implementation just delegates to the corresponding {@link Map} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer getOrDefault(final Object key, final Integer defaultValue) {
return Map.super.getOrDefault(key, defaultValue);
}
/** If the specified key is not already associated with a value, associates it with the given
* value and returns the {@linkplain #defaultReturnValue() default return value}, else returns
* the current value.
*
* @param key key with which the specified value is to be associated.
* @param value value to be associated with the specified key.
*
* @return the previous value associated with the specified key, or the {@linkplain #defaultReturnValue() default return value} if there was no mapping for the key.
*
* @see java.util.Map#putIfAbsent(Object, Object)
* @since 8.0.0
*/
default int putIfAbsent(final K key, final int value) {
final int v = getInt(key), drv = defaultReturnValue();
if (v != drv || containsKey(key)) return v;
put(key, value);
return drv;
}
/** Removes the entry for the specified key only if it is currently mapped to the specified value.
*
* @param key key with which the specified value is associated.
* @param value value expected to be associated with the specified key.
*
* @return {@code true} if the value was removed.
*
* @see java.util.Map#remove(Object, Object)
* @since 8.0.0
*/
default boolean remove(final Object key, final int value) {
final int curValue = getInt(key);
if (!( (curValue) == (value) ) || (curValue == defaultReturnValue() && !containsKey(key))) return false;
removeInt(key);
return true;
}
/** Replaces the entry for the specified key only if currently mapped to the specified value.
*
* @param key key with which the specified value is associated.
* @param oldValue value expected to be associated with the specified key.
* @param newValue value to be associated with the specified key.
*
* @return {@code true} if the value was replaced.
*
* @see java.util.Map#replace(Object, Object, Object)
* @since 8.0.0
*/
default boolean replace(final K key, final int oldValue, final int newValue) {
final int curValue = getInt(key);
if (!( (curValue) == (oldValue) ) || (curValue == defaultReturnValue() && !containsKey(key))) return false;
put(key, newValue);
return true;
}
/** Replaces the entry for the specified key only if it is currently mapped to some value.
*
* @param key key with which the specified value is associated.
* @param value value to be associated with the specified key.
*
* @return the previous value associated with the specified key, or the {@linkplain #defaultReturnValue() default return value} if there was no mapping for the key.
*
* @see java.util.Map#replace(Object, Object)
* @since 8.0.0
*/
default int replace(final K key, final int value) { return containsKey(key) ? put(key, value) : defaultReturnValue(); }
/** If the specified key is not already associated with a value, attempts to compute its value
* using the given mapping function and enters it into this map.
*
*
Note that contrarily to the default {@linkplain java.util.Map#computeIfAbsent(Object, java.util.function.Function) computeIfAbsent()},
* it is not possible to not add a value for a given key, since the {@code mappingFunction} cannot
* return {@code null}. If such a behavior is needed, please use the corresponding nullable version.
*
* @apiNote all {@code computeIfAbsent()} methods have a different logic based on the argument;
* no delegation is performed, contrarily to other superficially similar
* methods such as {@link java.util.Iterator#forEachRemaining} or {@link java.util.List#replaceAll}.
*
* @param key key with which the specified value is to be associated.
* @param mappingFunction the function to compute a value.
*
* @return the current (existing or computed) value associated with the specified key.
*
* @see java.util.Map#computeIfAbsent(Object, java.util.function.Function)
* @since 8.0.0
*/
default int computeIfAbsent(final K key, final java.util.function.ToIntFunction mappingFunction) {
java.util.Objects.requireNonNull(mappingFunction);
final int v = getInt(key);
if (v != defaultReturnValue() || containsKey(key)) return v;
int newValue = mappingFunction.applyAsInt(key);
put(key, newValue);
return newValue;
}
/**
* @deprecated Please use {@code computeIfAbsent()} instead.
*/
@Deprecated
default int computeIntIfAbsent(final K key, final java.util.function.ToIntFunction mappingFunction) {
return computeIfAbsent(key, mappingFunction);
}
/** If the specified key is not already associated with a value, attempts to compute its value
* using the given mapping function and enters it into this map, unless the key is not present
* in the given mapping function.
*
*
This version of {@linkplain java.util.Map#computeIfAbsent(Object, java.util.function.Function) computeIfAbsent()}
* uses a type-specific version of {@code fastutil}'s {@link it.unimi.dsi.fastutil.Function Function}.
* Since {@link it.unimi.dsi.fastutil.Function Function} has a {@link it.unimi.dsi.fastutil.Function#containsKey(Object) containsKey()}
* method, it is possible to avoid adding a key by having {@code containsKey()} return {@code false} for that key.
*
* @apiNote all {@code computeIfAbsent()} methods have a different logic based on the argument;
* no delegation is performed, contrarily to other superficially similar
* methods such as {@link java.util.Iterator#forEachRemaining} or {@link java.util.List#replaceAll}.
*
* @param key key with which the specified value is to be associated.
* @param mappingFunction the function to compute a value.
*
* @return the current (existing or computed) value associated with the specified key.
*
* @see java.util.Map#computeIfAbsent(Object, java.util.function.Function)
* @since 8.0.0
*/
default int computeIfAbsent(final K key, final Object2IntFunction mappingFunction) {
java.util.Objects.requireNonNull(mappingFunction);
final int v = getInt(key), drv = defaultReturnValue();
if (v != drv || containsKey(key)) return v;
if (!mappingFunction.containsKey(key)) return drv;
int newValue = mappingFunction.getInt(key);
put(key, newValue);
return newValue;
}
/**
* @deprecated Please use {@code computeIfAbsent()} instead.
*/
@Deprecated
default int computeIntIfAbsentPartial(final K key, final Object2IntFunction mappingFunction) {
return computeIfAbsent(key, mappingFunction);
}
/** If the value for the specified key is present, attempts to compute a new mapping given the key and its current mapped value.
*
* @apiNote The JDK specification for this method equates not being associated with a value with being associated with {code null}.
* This is not the case for this method.
*
* @param key key with which the specified value is to be associated.
* @param remappingFunction the function to compute a value.
*
* @return the new value associated with the specified key, or the {@linkplain #defaultReturnValue() default return value} if none.
*
* @see java.util.Map#computeIfPresent(Object, java.util.function.BiFunction)
* @since 8.0.0
*/
default int computeIntIfPresent(final K key, final java.util.function.BiFunction remappingFunction) {
java.util.Objects.requireNonNull(remappingFunction);
final int oldValue = getInt(key), drv = defaultReturnValue();
if (oldValue == drv && !containsKey(key)) return drv;
final Integer newValue = remappingFunction.apply((key), Integer.valueOf(oldValue));
if (newValue == null) { removeInt(key); return drv; }
int newVal = (newValue).intValue();
put(key, newVal);
return newVal;
}
/** Attempts to compute a mapping for the specified key and its current mapped value (or {@code null} if there is no current mapping).
*
*
If the function returns {@code null}, the mapping is removed (or remains absent if initially absent).
* If the function itself throws an (unchecked) exception, the exception is rethrown, and the current mapping is left unchanged.
*
* @param key key with which the specified value is to be associated.
* @param remappingFunction the function to compute a value.
*
* @return the new value associated with the specified key, or the {@linkplain #defaultReturnValue() default return value} if none.
*
* @see java.util.Map#compute(Object, java.util.function.BiFunction)
* @since 8.0.0
*/
default int computeInt(final K key, final java.util.function.BiFunction remappingFunction) {
java.util.Objects.requireNonNull(remappingFunction);
final int oldValue = getInt(key), drv = defaultReturnValue();
final boolean contained = oldValue != drv || containsKey(key);
final Integer newValue = remappingFunction.apply((key), contained ? Integer.valueOf(oldValue) : null);
if (newValue == null) {
if (contained) removeInt(key);
return drv;
}
final int newVal = (newValue).intValue();
put(key, newVal);
return newVal;
}
/**
* If the specified key is not already associated with a value, associates it with the given {@code value}.
* Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is {@code null}.
*
* @apiNote The JDK specification for this method equates not being associated with a value with being associated with {code null}.
* This is not the case for this method.
*
* @param key key with which the resulting value is to be associated.
* @param value the value to be merged with the existing value associated with the key or, if no existing value is associated with the key, to be associated with the key.
* @param remappingFunction the function to recompute a value if present.
*
* @return the new value associated with the specified key, or the {@linkplain #defaultReturnValue() default return value} if no value is associated with the key.
*
* @see java.util.Map#merge(Object, Object, java.util.function.BiFunction)
* @since 8.0.0
*/
default int merge(final K key, final int value, final java.util.function.BiFunction remappingFunction) {
java.util.Objects.requireNonNull(remappingFunction);
final int oldValue = getInt(key), drv = defaultReturnValue();
final int newValue;
if (oldValue != drv || containsKey(key)) {
final Integer mergedValue = remappingFunction.apply(Integer.valueOf(oldValue), Integer.valueOf(value));
if (mergedValue == null) { removeInt(key); return drv; }
newValue = (mergedValue).intValue();
} else {
newValue = value;
}
put(key, newValue);
return newValue;
}
/**
* If the specified key is not already associated with a value, associates it with the given {@code value}.
* Otherwise, replaces the associated value with the results of the given remapping function.
*
* @apiNote The JDK specification for this method equates not being associated with a value with being associated with {code null}.
* This is not the case for this method. Moreover, this method cannot delete entries as the type-specific remapping
* function cannot return {@code null}.
*
* @param key key with which the resulting value is to be associated.
* @param value the value to be merged with the existing value associated with the key or, if no existing value is associated with the key, to be associated with the key.
* @param remappingFunction the function to recompute a value if present.
*
* @return the new value associated with the specified key.
*
* @see java.util.Map#merge(Object, Object, java.util.function.BiFunction)
* @since 8.5.0
*/
default int mergeInt(final K key, final int value, final java.util.function.IntBinaryOperator remappingFunction) {
java.util.Objects.requireNonNull(remappingFunction);
final int oldValue = getInt(key), drv = defaultReturnValue();
final int newValue = oldValue != drv || containsKey(key) ? remappingFunction.applyAsInt(oldValue, value) : value;
put(key, newValue);
return newValue;
}
// Because our primitive BinaryOperator interface extends both the JDK's primitive
// and object BinaryOperator interfaces, calling this method with it would be ambiguous.
// This overload exists to pass it to the proper primitive overload.
/**
* If the specified key is not already associated with a value, associates it with the given {@code value}.
* Otherwise, replaces the associated value with the results of the given remapping function.
*
* @apiNote The JDK specification for this method equates not being associated with a value with being associated with {code null}.
* This is not the case for this method. Moreover, this method cannot delete entries as the type-specific remapping
* function cannot return {@code null}.
*
*
WARNING: Overriding this method is almost always a mistake, as this
* overload only exists to disambiguate. Instead, override the overload
* that uses the JDK's primitive binary operator (e.g. {@link java.util.function.IntBinaryOperator}).
*
*
If Java supported final default methods, this would be one, but sadly it does not.
*
*
If you checked and are overriding the version with {@code java.util.function.XBinaryOperator}, and
* still see this warning, then your IDE is incorrectly conflating this method with the proper
* method to override, and you can safely ignore this message.
*
* @param key key with which the resulting value is to be associated.
* @param value the value to be merged with the existing value associated with the key or, if no existing value is associated with the key, to be associated with the key.
* @param remappingFunction the function to recompute a value if present.
*
* @see java.util.Map#merge(Object, Object, java.util.function.BiFunction)
* @since 8.5.1
*/
default int mergeInt(final K key, final int value, final it.unimi.dsi.fastutil.ints.IntBinaryOperator remappingFunction) {
return mergeInt(key, value, (java.util.function.IntBinaryOperator)remappingFunction);
}
/**
* @deprecated Please use {@code merge()} instead.
*/
@Deprecated
default int mergeInt(final K key, final int value, final java.util.function.BiFunction remappingFunction) {
return merge(key, value, remappingFunction);
}
/** {@inheritDoc}
*
This default implementation just delegates to the corresponding {@link Map} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer putIfAbsent(final K key, final Integer value) {
return Map.super.putIfAbsent(key, value);
}
/** {@inheritDoc}
*
This default implementation just delegates to the corresponding {@link Map} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default boolean remove(final Object key, final Object value) {
return Map.super.remove(key, value);
}
/** {@inheritDoc}
*
This default implementation just delegates to the corresponding {@link Map} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default boolean replace(final K key, final Integer oldValue, final Integer newValue) {
return Map.super.replace(key, oldValue, newValue);
}
/** {@inheritDoc}
*
This default implementation just delegates to the corresponding {@link Map} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer replace(final K key, final Integer value) {
return Map.super.replace(key, value);
}
/** {@inheritDoc}
*
This default implementation just delegates to the corresponding {@link Map} method.
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer merge(final K key, final Integer value, final java.util.function.BiFunction remappingFunction) {
return Map.super.merge(key, value, remappingFunction);
}
/** A type-specific {@link java.util.Map.Entry}; provides some additional methods
* that use polymorphism to avoid (un)boxing.
*
* @see java.util.Map.Entry
*/
interface Entry extends Map.Entry {
/** Returns the value corresponding to this entry.
* @see java.util.Map.Entry#getValue()
*/
int getIntValue();
/** Replaces the value corresponding to this entry with the specified value (optional operation).
* @see java.util.Map.Entry#setValue(Object)
*/
int setValue(final int value);
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer getValue() {
return Integer.valueOf(getIntValue());
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Integer setValue(final Integer value) {
return Integer.valueOf(setValue((value).intValue()));
}
}
}