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/*
* Copyright (C) 2002-2017 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.doubles;
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 get(), put() and
* 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 cast to the return type (false
* for booleans) at creation, but can be changed using the
* defaultReturnValue() method.
*
*
For uniformity reasons, even maps returning objects implement the default
* return value (of course, in this case the default return value is
* initialized to {@code null}).
*
*
Warning: to fall in line as much as possible with the
* {@linkplain java.util.Map standard map interface}, it is strongly suggested
* that standard versions of get(), put() and
* remove() for maps with primitive-type values return
* {@code null} to denote missing keys rather than wrap the default
* return value in an object (of course, for maps with object keys and values
* this is not possible, as there is no type-specific version).
*
* @see Function
*/
public interface Double2ReferenceFunction extends Function {
/** 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)
*/
V put(double key, V value);
/** 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)
*/
V get(double key);
/** 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)
*/
V remove(double key);
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
V put(Double key, V value);
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
V get(Object key);
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
V remove(Object key);
/** Returns {@code true} if this map contains a mapping for the specified key.
* @see Function#containsKey(Object)
*/
boolean containsKey(double key);
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
boolean containsKey(Object key);
/** Sets the default return value.
*
* This value must be returned by type-specific versions of
* get(), put() and remove() to
* denote that the map does not contain the specified key. It must be
* 0/false/{@code null} by default.
*
* @param rv the new default return value.
* @see #defaultReturnValue()
*/
void defaultReturnValue(V rv);
/** Gets the default return value.
*
* @return the current default return value.
*/
V defaultReturnValue();
}