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/*
* 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.Function;
/** A type-specific {@link Function}; provides some additional methods that use polymorphism to avoid (un)boxing.
*
* Type-specific versions of {@code get()}, {@code put()} and
* {@code remove()} cannot rely on {@code null} to denote absence of
* a key. Rather, they return a {@linkplain #defaultReturnValue() default
* return value}, which is set to 0/false at creation, but can be changed using
* the {@code defaultReturnValue()} method.
*
*
For uniformity reasons, even functions returning objects implement the default
* return value (of course, in this case the default return value is
* initialized to {@code null}).
*
*
The default implementation of optional operations just throw an {@link
* UnsupportedOperationException}, except for the type-specific {@code
* containsKey()}, which return true. Generic versions of accessors delegate to
* the corresponding type-specific counterparts following the interface rules.
*
*
Warning: to fall in line as much as possible with the
* {@linkplain java.util.Map standard map interface}, it is required that
* standard versions of {@code get()}, {@code put()} and
* {@code remove()} for maps with primitive-type keys or values return
* {@code null} to denote missing keys rather than wrap the default
* return value in an object. In case both keys and values are reference
* types, the default return value must be returned instead, thus violating
* the {@linkplain java.util.Map standard map interface} when the default
* return value is not {@code null}.
*
* @see Function
*/
@FunctionalInterface
public interface Reference2CharFunction extends Function, java.util.function.ToIntFunction {
/** {@inheritDoc}
* @since 8.0.0
*/
@Override
default int applyAsInt(K operand) { return getChar(operand); }
/** Adds a pair to the map (optional operation).
*
* @param key the key.
* @param value the value.
* @return the old value, or the {@linkplain #defaultReturnValue() default return value} if no value was present for the given key.
* @see Function#put(Object,Object)
*/
default char put(final K key, final char value) {
throw new UnsupportedOperationException();
}
/** Returns the value to which the given key is mapped.
*
* @param key the key.
* @return the corresponding value, or the {@linkplain #defaultReturnValue() default return value} if no value was present for the given key.
* @see Function#get(Object)
*/
char getChar(Object key);
/** Returns the value associated by this function to the specified key, or give the specified
* value if not present.
*
* @param key the key.
* @param defaultValue the value to return if not present.
* @return the corresponding value, or {@code defaultValue} if no value was present for the given key.
* @see Function#getOrDefault(Object, Object)
* @since 8.5.0
*/
default char getOrDefault(final Object key, final char defaultValue) {
final char v;
return ((v = getChar(key)) != defaultReturnValue() || containsKey(key)) ? v : defaultValue;
}
/** Removes the mapping with the given key (optional operation).
* @param key the key.
* @return the old value, or the {@linkplain #defaultReturnValue() default return value} if no value was present for the given key.
* @see Function#remove(Object)
*/
default char removeChar(final Object key) {
throw new UnsupportedOperationException();
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Character put(final K key, final Character value) {
final K k = (key);
final boolean containsKey = containsKey(k);
final char v = put(k, (value).charValue());
return containsKey ? Character.valueOf(v) : null;
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Character get(final Object key) {
final Object k = (key);
final char v;
return ((v = getChar(k)) != defaultReturnValue() || containsKey(k)) ? Character.valueOf(v) : null;
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Character getOrDefault(final Object key, Character defaultValue) {
final Object k = (key);
final char v = getChar(k);
return (v != defaultReturnValue() || containsKey(k)) ? Character.valueOf(v) : defaultValue;
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default Character remove(final Object key) {
final Object k = (key);
return containsKey(k) ? Character.valueOf(removeChar(k)) : null;
}
/** 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}/{@code null} by default.
*
* @param rv the new default return value.
* @see #defaultReturnValue()
*/
default void defaultReturnValue(char rv) {
throw new UnsupportedOperationException();
}
/** Gets the default return value.
*
* This default implementation just return the default null value
* of the type ({@code null} for objects, 0 for scalars, false for Booleans).
*
* @return the current default return value.
*/
default char defaultReturnValue() {
return ((char)0);
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead.
*/
@Deprecated
@Override
default java.util.function.Function andThen(java.util.function.Function after) {
return Function.super.andThen(after);
}
default it.unimi.dsi.fastutil.objects.Reference2ByteFunction andThenByte(it.unimi.dsi.fastutil.chars.Char2ByteFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.bytes.Byte2CharFunction composeByte(it.unimi.dsi.fastutil.bytes.Byte2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2ShortFunction andThenShort(it.unimi.dsi.fastutil.chars.Char2ShortFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.shorts.Short2CharFunction composeShort(it.unimi.dsi.fastutil.shorts.Short2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2IntFunction andThenInt(it.unimi.dsi.fastutil.chars.Char2IntFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.ints.Int2CharFunction composeInt(it.unimi.dsi.fastutil.ints.Int2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2LongFunction andThenLong(it.unimi.dsi.fastutil.chars.Char2LongFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.longs.Long2CharFunction composeLong(it.unimi.dsi.fastutil.longs.Long2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2CharFunction andThenChar(it.unimi.dsi.fastutil.chars.Char2CharFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.chars.Char2CharFunction composeChar(it.unimi.dsi.fastutil.chars.Char2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2FloatFunction andThenFloat(it.unimi.dsi.fastutil.chars.Char2FloatFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.floats.Float2CharFunction composeFloat(it.unimi.dsi.fastutil.floats.Float2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2DoubleFunction andThenDouble(it.unimi.dsi.fastutil.chars.Char2DoubleFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.doubles.Double2CharFunction composeDouble(it.unimi.dsi.fastutil.doubles.Double2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2ObjectFunction andThenObject(it.unimi.dsi.fastutil.chars.Char2ObjectFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.objects.Object2CharFunction composeObject(it.unimi.dsi.fastutil.objects.Object2ReferenceFunction before) { return k -> getChar(before.get(k)); }
default it.unimi.dsi.fastutil.objects.Reference2ReferenceFunction andThenReference(it.unimi.dsi.fastutil.chars.Char2ReferenceFunction after) { return k -> after.get(getChar(k)); } default it.unimi.dsi.fastutil.objects.Reference2CharFunction composeReference(it.unimi.dsi.fastutil.objects.Reference2ReferenceFunction before) { return k -> getChar(before.get(k)); }
}