src.it.unimi.dsi.fastutil.objects.Reference2ReferenceFunction Maven / Gradle / Ivy
/* Generic definitions */
/* Assertions (useful to generate conditional code) */
/* Current type and class (and size, if applicable) */
/* Value methods */
/* Interfaces (keys) */
/* Interfaces (values) */
/* Abstract implementations (keys) */
/* Abstract implementations (values) */
/* Static containers (keys) */
/* Static containers (values) */
/* Implementations */
/* Synchronized wrappers */
/* Unmodifiable wrappers */
/* Other wrappers */
/* Methods (keys) */
/* Methods (values) */
/* Methods (keys/values) */
/* Methods that have special names depending on keys (but the special names depend on values) */
/* Equality */
/* Object/Reference-only definitions (keys) */
/* Object/Reference-only definitions (values) */
/*
* Copyright (C) 2002-2013 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 get(), put() and
* remove() cannot rely on 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 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
* 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 Reference2ReferenceFunction extends Function {
/** 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/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();
}