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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 PACKAGE;
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
#ifdef JDK_PRIMITIVE_FUNCTION
public interface FUNCTION KEY_VALUE_GENERIC extends Function, JDK_PRIMITIVE_FUNCTION KEY_GENERIC VALUE_GENERIC {
#else
public interface FUNCTION KEY_VALUE_GENERIC extends Function {
#endif
#ifdef JDK_PRIMITIVE_FUNCTION
#if KEYS_BYTE_CHAR_SHORT_FLOAT
/** {@inheritDoc}
*
* @implSpec This default implementation delegates to the type-specific
* {@code get()} method after narrowing down the key to the
* actual key type, throwing an exception if the given key cannot be
* represented in the restricted domain. This is done for interoperability
* with the Java 8 function environment. The use of this method is discouraged, as
* unexpected errors can occur. Instead, the corresponding classes should be
* used (e.g., {@link it.unimi.dsi.fastutil.ints.Int2IntFunction} instead of
* {@link it.unimi.dsi.fastutil.shorts.Short2IntFunction}).
*
* @throws IllegalArgumentException If the given operand is not an element of the key domain.
* @since 8.0.0
* @deprecated Please use primitive types which do not have to be widened as keys.
*/
@Deprecated
#else
/** {@inheritDoc}
* @since 8.0.0
*/
#endif
@Override
default VALUE_GENERIC_TYPE_WIDENED JDK_PRIMITIVE_FUNCTION_APPLY(KEY_GENERIC_TYPE_WIDENED operand) { return GET_VALUE(KEY_NARROWING(operand)); }
#endif
/** 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 VALUE_GENERIC_TYPE put(final KEY_GENERIC_TYPE key, final VALUE_GENERIC_TYPE 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)
*/
VALUE_GENERIC_TYPE GET_VALUE(KEY_TYPE 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 VALUE_GENERIC_TYPE getOrDefault(final KEY_TYPE key, final VALUE_GENERIC_TYPE defaultValue) {
final VALUE_GENERIC_TYPE v;
return ((v = GET_VALUE(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 VALUE_GENERIC_TYPE REMOVE_VALUE(final KEY_TYPE key) {
throw new UnsupportedOperationException();
}
#if KEYS_PRIMITIVE || VALUES_PRIMITIVE
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default VALUE_GENERIC_CLASS put(final KEY_GENERIC_CLASS key, final VALUE_GENERIC_CLASS value) {
final KEY_GENERIC_TYPE k = KEY_CLASS2TYPE(key);
final boolean containsKey = containsKey(k);
final VALUE_GENERIC_TYPE v = put(k, VALUE_CLASS2TYPE(value));
return containsKey ? VALUE2OBJ(v) : null;
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default VALUE_GENERIC_CLASS get(final Object key) {
#if KEYS_PRIMITIVE
if (key == null) return null;
#endif
final KEY_TYPE k = KEY_OBJ2TYPE(key);
final VALUE_GENERIC_TYPE v;
return ((v = GET_VALUE(k)) != defaultReturnValue() || containsKey(k)) ? VALUE2OBJ(v) : null;
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default VALUE_GENERIC_CLASS getOrDefault(final Object key, VALUE_GENERIC_CLASS defaultValue) {
#if KEYS_PRIMITIVE
if (key == null) return defaultValue;
#endif
final KEY_TYPE k = KEY_OBJ2TYPE(key);
final VALUE_GENERIC_TYPE v = GET_VALUE(k);
return (v != defaultReturnValue() || containsKey(k)) ? VALUE2OBJ(v) : defaultValue;
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default VALUE_GENERIC_CLASS remove(final Object key) {
#if KEYS_PRIMITIVE
if (key == null) return null;
#endif
final KEY_TYPE k = KEY_OBJ2TYPE(key);
return containsKey(k) ? VALUE2OBJ(REMOVE_VALUE(k)) : null;
}
#if KEYS_PRIMITIVE
/** Returns true if this function contains a mapping for the specified key.
*
* Note that for some kind of functions (e.g., hashes) this method will
* always return true. In particular, this default implementation always
* returns true.
*
* @param key the key.
* @return true if this function associates a value to {@code key}.
* @see Function#containsKey(Object)
*/
default boolean containsKey(KEY_TYPE key) {
return true;
}
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead. */
@Deprecated
@Override
default boolean containsKey(final Object key) {
return key == null ? false : containsKey(KEY_OBJ2TYPE(key));
}
#endif
#endif
/** 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(VALUE_GENERIC_TYPE 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 VALUE_GENERIC_TYPE defaultReturnValue() {
return VALUE_NULL;
}
#if KEYS_PRIMITIVE && (KEY_INDEX == VALUE_INDEX)
static KEY_VALUE_GENERIC FUNCTION identity() {
return k -> k;
}
#endif
#define FUNCTION_NAME(K, V) K ## 2 ## V ## Function
#if KEYS_REFERENCE && VALUES_REFERENCE
#define K_T_G
#define T_K_G
#define V_T_G
#define T_V_G
#else
#if KEYS_PRIMITIVE
#define K_T_G
#define T_K_G
#else
#define K_T_G
#define T_K_G
#endif
#if VALUES_PRIMITIVE
#define V_T_G
#define T_V_G
#else
#define V_T_G
#define T_V_G
#endif
#endif
#if KEYS_PRIMITIVE
/** {@inheritDoc}
* @deprecated Please use the corresponding type-specific method instead.
*/
@Deprecated
@Override
default java.util.function.Function compose(java.util.function.Function before) {
return Function.super.compose(before);
}
#define GET_BEFORE GET_KEY
#else
#define GET_BEFORE get
#endif
#if VALUES_PRIMITIVE
/** {@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);
}
#define GET_AFTER(T_C) get
#else
#define GET_AFTER(T_C) get ## T_C
#endif
#define COMPOSITION(K_C, V_C, T_C, T_P, G_A, G_B, T_G, K_T_G, V_T_G, T_V_G, T_K_G) \
default T_G PACKAGE.FUNCTION_NAME(K_C, T_C) K_T_G andThen ## T_C(VALUE_PACKAGE.FUNCTION_NAME(V_C, T_C) V_T_G after) { \
return k -> after.G_A(GET_VALUE(k)); \
} \
default T_G it.unimi.dsi.fastutil.T_P.FUNCTION_NAME(T_C, V_C) T_V_G compose ## T_C(it.unimi.dsi.fastutil.T_P.FUNCTION_NAME(T_C, K_C) T_K_G before) { \
return k -> GET_VALUE(before.G_B(k)); \
}
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Byte, bytes, GET_AFTER(Byte), get, , KEY_GENERIC, VALUE_GENERIC, VALUE_GENERIC, KEY_GENERIC)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Short, shorts, GET_AFTER(Short), get, , KEY_GENERIC, VALUE_GENERIC, VALUE_GENERIC, KEY_GENERIC)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Int, ints, GET_AFTER(Int), get, , KEY_GENERIC, VALUE_GENERIC, VALUE_GENERIC, KEY_GENERIC)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Long, longs, GET_AFTER(Long), get, , KEY_GENERIC, VALUE_GENERIC, VALUE_GENERIC, KEY_GENERIC)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Char, chars, GET_AFTER(Char), get, , KEY_GENERIC, VALUE_GENERIC, VALUE_GENERIC, KEY_GENERIC)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Float, floats, GET_AFTER(Float), get, , KEY_GENERIC, VALUE_GENERIC, VALUE_GENERIC, KEY_GENERIC)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Double, doubles, GET_AFTER(Double), get, , KEY_GENERIC, VALUE_GENERIC, VALUE_GENERIC, KEY_GENERIC)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Object, objects, get, GET_BEFORE, , K_T_G, V_T_G, T_V_G, T_K_G)
COMPOSITION(KEY_TYPE_CAP, VALUE_TYPE_CAP, Reference, objects, get, GET_BEFORE, , K_T_G, V_T_G, T_V_G, T_K_G)
}