Java tutorial
/* * Copyright (c) 2016 Gridtec. All rights reserved. * * 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 at.gridtec.lambda4j.function.bi.obj; import at.gridtec.lambda4j.Lambda; import at.gridtec.lambda4j.consumer.bi.obj.ObjDoubleConsumer2; import at.gridtec.lambda4j.function.BooleanFunction; import at.gridtec.lambda4j.function.ByteFunction; import at.gridtec.lambda4j.function.CharFunction; import at.gridtec.lambda4j.function.FloatFunction; import at.gridtec.lambda4j.function.ShortFunction; import at.gridtec.lambda4j.function.bi.BiFunction2; import at.gridtec.lambda4j.function.bi.conversion.BiBooleanToDoubleFunction; import at.gridtec.lambda4j.function.bi.conversion.BiByteToDoubleFunction; import at.gridtec.lambda4j.function.bi.conversion.BiCharToDoubleFunction; import at.gridtec.lambda4j.function.bi.conversion.BiFloatToDoubleFunction; import at.gridtec.lambda4j.function.bi.conversion.BiIntToDoubleFunction; import at.gridtec.lambda4j.function.bi.conversion.BiLongToDoubleFunction; import at.gridtec.lambda4j.function.bi.conversion.BiShortToDoubleFunction; import at.gridtec.lambda4j.function.bi.to.ToDoubleBiFunction2; import at.gridtec.lambda4j.function.conversion.BooleanToDoubleFunction; import at.gridtec.lambda4j.function.conversion.ByteToDoubleFunction; import at.gridtec.lambda4j.function.conversion.CharToDoubleFunction; import at.gridtec.lambda4j.function.conversion.DoubleToByteFunction; import at.gridtec.lambda4j.function.conversion.DoubleToCharFunction; import at.gridtec.lambda4j.function.conversion.DoubleToFloatFunction; import at.gridtec.lambda4j.function.conversion.DoubleToShortFunction; import at.gridtec.lambda4j.function.conversion.FloatToDoubleFunction; import at.gridtec.lambda4j.function.conversion.ShortToDoubleFunction; import at.gridtec.lambda4j.function.to.ToDoubleFunction2; import at.gridtec.lambda4j.operator.binary.DoubleBinaryOperator2; import at.gridtec.lambda4j.operator.unary.DoubleUnaryOperator2; import at.gridtec.lambda4j.predicate.bi.obj.ObjDoublePredicate; import org.apache.commons.lang3.tuple.Pair; import javax.annotation.Nonnegative; import javax.annotation.Nonnull; import javax.annotation.Nullable; import java.util.Map; import java.util.Objects; import java.util.concurrent.ConcurrentHashMap; import java.util.function.DoubleConsumer; import java.util.function.DoubleFunction; import java.util.function.DoublePredicate; import java.util.function.DoubleToIntFunction; import java.util.function.DoubleToLongFunction; import java.util.function.DoubleUnaryOperator; import java.util.function.Function; import java.util.function.IntFunction; import java.util.function.IntToDoubleFunction; import java.util.function.LongFunction; import java.util.function.LongToDoubleFunction; import java.util.function.ToDoubleFunction; /** * Represents an operation that accepts one object-valued and one {@code double}-valued input argument and produces a * {@code double}-valued result. * This is a (reference, double) specialization of {@link BiFunction2}. * <p> * This is a {@link FunctionalInterface} whose functional method is {@link #applyAsDouble(Object, double)}. * * @param <T> The type of the first argument to the function * @see BiFunction2 */ @SuppressWarnings("unused") @FunctionalInterface public interface ObjDoubleToDoubleFunction<T> extends Lambda { /** * Constructs a {@link ObjDoubleToDoubleFunction} based on a lambda expression or a method reference. Thereby the * given lambda expression or method reference is returned on an as-is basis to implicitly transform it to the * desired type. With this method, it is possible to ensure that correct type is used from lambda expression or * method reference. * * @param <T> The type of the first argument to the function * @param expression A lambda expression or (typically) a method reference, e.g. {@code this::method} * @return A {@code ObjDoubleToDoubleFunction} from given lambda expression or method reference. * @implNote This implementation allows the given argument to be {@code null}, but only if {@code null} given, * {@code null} will be returned. * @see <a href="https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html#syntax">Lambda * Expression</a> * @see <a href="https://docs.oracle.com/javase/tutorial/java/javaOO/methodreferences.html">Method Reference</a> */ static <T> ObjDoubleToDoubleFunction<T> of(@Nullable final ObjDoubleToDoubleFunction<T> expression) { return expression; } /** * Calls the given {@link ObjDoubleToDoubleFunction} with the given arguments and returns its result. * * @param <T> The type of the first argument to the function * @param function The function to be called * @param t The first argument to the function * @param value The second argument to the function * @return The result from the given {@code ObjDoubleToDoubleFunction}. * @throws NullPointerException If given argument is {@code null} */ static <T> double call(@Nonnull final ObjDoubleToDoubleFunction<? super T> function, T t, double value) { Objects.requireNonNull(function); return function.applyAsDouble(t, value); } /** * Creates a {@link ObjDoubleToDoubleFunction} which uses the {@code first} parameter of this one as argument for * the given {@link ToDoubleFunction}. * * @param <T> The type of the first argument to the function * @param function The function which accepts the {@code first} parameter of this one * @return Creates a {@code ObjDoubleToDoubleFunction} which uses the {@code first} parameter of this one as * argument for the given {@code ToDoubleFunction}. * @throws NullPointerException If given argument is {@code null} */ @Nonnull static <T> ObjDoubleToDoubleFunction<T> onlyFirst(@Nonnull final ToDoubleFunction<? super T> function) { Objects.requireNonNull(function); return (t, value) -> function.applyAsDouble(t); } /** * Creates a {@link ObjDoubleToDoubleFunction} which uses the {@code second} parameter of this one as argument for * the given {@link DoubleUnaryOperator}. * * @param <T> The type of the first argument to the function * @param operator The operator which accepts the {@code second} parameter of this one * @return Creates a {@code ObjDoubleToDoubleFunction} which uses the {@code second} parameter of this one as * argument for the given {@code DoubleUnaryOperator}. * @throws NullPointerException If given argument is {@code null} */ @Nonnull static <T> ObjDoubleToDoubleFunction<T> onlySecond(@Nonnull final DoubleUnaryOperator operator) { Objects.requireNonNull(operator); return (t, value) -> operator.applyAsDouble(value); } /** * Creates a {@link ObjDoubleToDoubleFunction} which always returns a given value. * * @param <T> The type of the first argument to the function * @param ret The return value for the constant * @return A {@code ObjDoubleToDoubleFunction} which always returns a given value. */ @Nonnull static <T> ObjDoubleToDoubleFunction<T> constant(double ret) { return (t, value) -> ret; } /** * Applies this function to the given arguments. * * @param t The first argument to the function * @param value The second argument to the function * @return The return value from the function, which is its result. */ double applyAsDouble(T t, double value); /** * Applies this operator partially to some arguments of this one, producing a {@link DoubleUnaryOperator2} as * result. * * @param t The first argument to this function used to partially apply this function * @return A {@code DoubleUnaryOperator2} that represents this operator partially applied the some arguments. */ @Nonnull default DoubleUnaryOperator2 papplyAsDouble(T t) { return (value) -> this.applyAsDouble(t, value); } /** * Applies this operator partially to some arguments of this one, producing a {@link ToDoubleFunction2} as result. * * @param value The second argument to this function used to partially apply this function * @return A {@code ToDoubleFunction2} that represents this operator partially applied the some arguments. */ @Nonnull default ToDoubleFunction2<T> papplyAsDouble(double value) { return (t) -> this.applyAsDouble(t, value); } /** * Returns the number of arguments for this function. * * @return The number of arguments for this function. * @implSpec The default implementation always returns {@code 2}. */ @Nonnegative default int arity() { return 2; } /** * Returns a composed {@link ToDoubleBiFunction2} that first applies the {@code before} functions to its input, and * then applies this function to the result. * If evaluation of either operation throws an exception, it is relayed to the caller of the composed operation. * * @param <A> The type of the argument to the first given function, and of composed function * @param <B> The type of the argument to the second given function, and of composed function * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code ToDoubleBiFunction2} that first applies the {@code before} functions to its input, and * then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is able to handle every type. */ @Nonnull default <A, B> ToDoubleBiFunction2<A, B> compose(@Nonnull final Function<? super A, ? extends T> before1, @Nonnull final ToDoubleFunction<? super B> before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (a, b) -> applyAsDouble(before1.apply(a), before2.applyAsDouble(b)); } /** * Returns a composed {@link BiBooleanToDoubleFunction} that first applies the {@code before} functions to its * input, and then applies this function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * execute an operation which accepts {@code boolean} input, before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code BiBooleanToDoubleFunction} that first applies the {@code before} functions to its * input, and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * boolean}. */ @Nonnull default BiBooleanToDoubleFunction composeFromBoolean(@Nonnull final BooleanFunction<? extends T> before1, @Nonnull final BooleanToDoubleFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link BiByteToDoubleFunction} that first applies the {@code before} functions to * its input, and then applies this function to the result. * If evaluation of either operation throws an exception, it is relayed to the caller of the composed operation. * This method is just convenience, to provide the ability to execute an operation which accepts {@code byte} input, * before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code BiByteToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * byte}. */ @Nonnull default BiByteToDoubleFunction composeFromByte(@Nonnull final ByteFunction<? extends T> before1, @Nonnull final ByteToDoubleFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link BiCharToDoubleFunction} that first applies the {@code before} functions to * its input, and then applies this function to the result. * If evaluation of either operation throws an exception, it is relayed to the caller of the composed operation. * This method is just convenience, to provide the ability to execute an operation which accepts {@code char} input, * before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code BiCharToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * char}. */ @Nonnull default BiCharToDoubleFunction composeFromChar(@Nonnull final CharFunction<? extends T> before1, @Nonnull final CharToDoubleFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link DoubleBinaryOperator2} that first applies the {@code before} functions to its input, * and then applies this function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * execute an operation which accepts {@code double} input, before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second operator to apply before this function is applied * @return A composed {@code DoubleBinaryOperator2} that first applies the {@code before} functions to its input, * and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * double}. */ @Nonnull default DoubleBinaryOperator2 composeFromDouble(@Nonnull final DoubleFunction<? extends T> before1, @Nonnull final DoubleUnaryOperator before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link BiFloatToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * execute an operation which accepts {@code float} input, before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code BiFloatToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * float}. */ @Nonnull default BiFloatToDoubleFunction composeFromFloat(@Nonnull final FloatFunction<? extends T> before1, @Nonnull final FloatToDoubleFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link BiIntToDoubleFunction} that first applies the {@code before} functions to * its input, and then applies this function to the result. * If evaluation of either operation throws an exception, it is relayed to the caller of the composed operation. * This method is just convenience, to provide the ability to execute an operation which accepts {@code int} input, * before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code BiIntToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * int}. */ @Nonnull default BiIntToDoubleFunction composeFromInt(@Nonnull final IntFunction<? extends T> before1, @Nonnull final IntToDoubleFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link BiLongToDoubleFunction} that first applies the {@code before} functions to * its input, and then applies this function to the result. * If evaluation of either operation throws an exception, it is relayed to the caller of the composed operation. * This method is just convenience, to provide the ability to execute an operation which accepts {@code long} input, * before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code BiLongToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * long}. */ @Nonnull default BiLongToDoubleFunction composeFromLong(@Nonnull final LongFunction<? extends T> before1, @Nonnull final LongToDoubleFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link BiShortToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * execute an operation which accepts {@code short} input, before this primitive function is executed. * * @param before1 The first function to apply before this function is applied * @param before2 The second function to apply before this function is applied * @return A composed {@code BiShortToDoubleFunction} that first applies the {@code before} functions to its input, * and then applies this function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to handle primitive values. In this case this is {@code * short}. */ @Nonnull default BiShortToDoubleFunction composeFromShort(@Nonnull final ShortFunction<? extends T> before1, @Nonnull final ShortToDoubleFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsDouble(before1.apply(value1), before2.applyAsDouble(value2)); } /** * Returns a composed {@link ObjDoubleFunction} that first applies this function to its input, and then applies the * {@code after} function to the result. * If evaluation of either operation throws an exception, it is relayed to the caller of the composed operation. * * @param <S> The type of return value from the {@code after} function, and of the composed function * @param after The function to apply after this function is applied * @return A composed {@code ObjDoubleFunction} that first applies this function to its input, and then applies the * {@code after} function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is able to return every type. */ @Nonnull default <S> ObjDoubleFunction<T, S> andThen(@Nonnull final DoubleFunction<? extends S> after) { Objects.requireNonNull(after); return (t, value) -> after.apply(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoublePredicate} that first applies this function to its input, and then applies the * {@code after} predicate to the result. If evaluation of either operation throws an exception, it is relayed to * the caller of the composed operation. This method is just convenience, to provide the ability to transform this * primitive function to an operation returning {@code boolean}. * * @param after The predicate to apply after this function is applied * @return A composed {@code ObjDoublePredicate} that first applies this function to its input, and then applies the * {@code after} predicate to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * boolean}. */ @Nonnull default ObjDoublePredicate<T> andThenToBoolean(@Nonnull final DoublePredicate after) { Objects.requireNonNull(after); return (t, value) -> after.test(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleToByteFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * transform this primitive function to an operation returning {@code byte}. * * @param after The function to apply after this function is applied * @return A composed {@code ObjDoubleToByteFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * byte}. */ @Nonnull default ObjDoubleToByteFunction<T> andThenToByte(@Nonnull final DoubleToByteFunction after) { Objects.requireNonNull(after); return (t, value) -> after.applyAsByte(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleToCharFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * transform this primitive function to an operation returning {@code char}. * * @param after The function to apply after this function is applied * @return A composed {@code ObjDoubleToCharFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * char}. */ @Nonnull default ObjDoubleToCharFunction<T> andThenToChar(@Nonnull final DoubleToCharFunction after) { Objects.requireNonNull(after); return (t, value) -> after.applyAsChar(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleToDoubleFunction} that first applies this function to its input, and then * applies the {@code after} operator to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * transform this primitive function to an operation returning {@code double}. * * @param after The operator to apply after this function is applied * @return A composed {@code ObjDoubleToDoubleFunction} that first applies this function to its input, and then * applies the {@code after} operator to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * double}. */ @Nonnull default ObjDoubleToDoubleFunction<T> andThenToDouble(@Nonnull final DoubleUnaryOperator after) { Objects.requireNonNull(after); return (t, value) -> after.applyAsDouble(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleToFloatFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * transform this primitive function to an operation returning {@code float}. * * @param after The function to apply after this function is applied * @return A composed {@code ObjDoubleToFloatFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * float}. */ @Nonnull default ObjDoubleToFloatFunction<T> andThenToFloat(@Nonnull final DoubleToFloatFunction after) { Objects.requireNonNull(after); return (t, value) -> after.applyAsFloat(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleToIntFunction} that first applies this function to its input, and then applies * the {@code after} function to the result. If evaluation of either operation throws an exception, it is relayed to * the caller of the composed operation. This method is just convenience, to provide the ability to transform this * primitive function to an operation returning {@code int}. * * @param after The function to apply after this function is applied * @return A composed {@code ObjDoubleToIntFunction} that first applies this function to its input, and then applies * the {@code after} function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * int}. */ @Nonnull default ObjDoubleToIntFunction<T> andThenToInt(@Nonnull final DoubleToIntFunction after) { Objects.requireNonNull(after); return (t, value) -> after.applyAsInt(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleToLongFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * transform this primitive function to an operation returning {@code long}. * * @param after The function to apply after this function is applied * @return A composed {@code ObjDoubleToLongFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * long}. */ @Nonnull default ObjDoubleToLongFunction<T> andThenToLong(@Nonnull final DoubleToLongFunction after) { Objects.requireNonNull(after); return (t, value) -> after.applyAsLong(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleToShortFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. This method is just convenience, to provide the ability to * transform this primitive function to an operation returning {@code short}. * * @param after The function to apply after this function is applied * @return A composed {@code ObjDoubleToShortFunction} that first applies this function to its input, and then * applies the {@code after} function to the result. * @throws NullPointerException If given argument is {@code null} * @implSpec The input argument of this method is a able to return primitive values. In this case this is {@code * short}. */ @Nonnull default ObjDoubleToShortFunction<T> andThenToShort(@Nonnull final DoubleToShortFunction after) { Objects.requireNonNull(after); return (t, value) -> after.applyAsShort(applyAsDouble(t, value)); } /** * Returns a composed {@link ObjDoubleConsumer2} that fist applies this function to its input, and then consumes the * result using the given {@link DoubleConsumer}. If evaluation of either operation throws an exception, it is * relayed to the caller of the composed operation. * * @param consumer The operation which consumes the result from this operation * @return A composed {@code ObjDoubleConsumer2} that first applies this function to its input, and then consumes * the result using the given {@code DoubleConsumer}. * @throws NullPointerException If given argument is {@code null} */ @Nonnull default ObjDoubleConsumer2<T> consume(@Nonnull final DoubleConsumer consumer) { Objects.requireNonNull(consumer); return (t, value) -> consumer.accept(applyAsDouble(t, value)); } /** * Returns a memoized (caching) version of this {@link ObjDoubleToDoubleFunction}. Whenever it is called, the * mapping between the input parameters and the return value is preserved in a cache, making subsequent calls * returning the memoized value instead of computing the return value again. * <p> * Unless the function and therefore the used cache will be garbage-collected, it will keep all memoized values * forever. * * @return A memoized (caching) version of this {@code ObjDoubleToDoubleFunction}. * @implSpec This implementation does not allow the input parameters or return value to be {@code null} for the * resulting memoized function, as the cache used internally does not permit {@code null} keys or values. * @implNote The returned memoized function can be safely used concurrently from multiple threads which makes it * thread-safe. */ @Nonnull default ObjDoubleToDoubleFunction<T> memoized() { if (isMemoized()) { return this; } else { final Map<Pair<T, Double>, Double> cache = new ConcurrentHashMap<>(); final Object lock = new Object(); return (ObjDoubleToDoubleFunction<T> & Memoized) (t, value) -> { final double returnValue; synchronized (lock) { returnValue = cache.computeIfAbsent(Pair.of(t, value), key -> applyAsDouble(key.getLeft(), key.getRight())); } return returnValue; }; } } /** * Returns a composed {@link BiFunction2} which represents this {@link ObjDoubleToDoubleFunction}. Thereby the * primitive input argument for this function is autoboxed. This method provides the possibility to use this {@code * ObjDoubleToDoubleFunction} with methods provided by the {@code JDK}. * * @return A composed {@code BiFunction2} which represents this {@code ObjDoubleToDoubleFunction}. */ @Nonnull default BiFunction2<T, Double, Double> boxed() { return this::applyAsDouble; } }