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.conversion; import at.gridtec.lambda4j.Lambda; import at.gridtec.lambda4j.consumer.bi.BiLongConsumer; import at.gridtec.lambda4j.function.bi.BiFunction2; import at.gridtec.lambda4j.function.bi.BiLongFunction; import at.gridtec.lambda4j.function.bi.to.ToIntBiFunction2; import at.gridtec.lambda4j.function.conversion.BooleanToLongFunction; import at.gridtec.lambda4j.function.conversion.ByteToLongFunction; import at.gridtec.lambda4j.function.conversion.CharToLongFunction; import at.gridtec.lambda4j.function.conversion.FloatToLongFunction; import at.gridtec.lambda4j.function.conversion.IntToByteFunction; import at.gridtec.lambda4j.function.conversion.IntToCharFunction; import at.gridtec.lambda4j.function.conversion.IntToFloatFunction; import at.gridtec.lambda4j.function.conversion.IntToShortFunction; import at.gridtec.lambda4j.function.conversion.LongToIntFunction2; import at.gridtec.lambda4j.function.conversion.ShortToLongFunction; import at.gridtec.lambda4j.operator.binary.IntBinaryOperator2; import at.gridtec.lambda4j.operator.binary.LongBinaryOperator2; import at.gridtec.lambda4j.predicate.bi.BiLongPredicate; 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.DoubleToLongFunction; import java.util.function.IntConsumer; import java.util.function.IntFunction; import java.util.function.IntPredicate; import java.util.function.IntToDoubleFunction; import java.util.function.IntToLongFunction; import java.util.function.IntUnaryOperator; import java.util.function.LongToIntFunction; import java.util.function.LongUnaryOperator; import java.util.function.ToLongFunction; /** * Represents an operation that accepts two {@code long}-valued input arguments and produces a * {@code int}-valued result. * This is a primitive specialization of {@link BiFunction2}. * <p> * This is a {@link FunctionalInterface} whose functional method is {@link #applyAsInt(long, long)}. * * @see BiFunction2 */ @SuppressWarnings("unused") @FunctionalInterface public interface BiLongToIntFunction extends Lambda { /** * Constructs a {@link BiLongToIntFunction} 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 expression A lambda expression or (typically) a method reference, e.g. {@code this::method} * @return A {@code BiLongToIntFunction} 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 BiLongToIntFunction of(@Nullable final BiLongToIntFunction expression) { return expression; } /** * Calls the given {@link BiLongToIntFunction} with the given arguments and returns its result. * * @param function The function to be called * @param value1 The first argument to the function * @param value2 The second argument to the function * @return The result from the given {@code BiLongToIntFunction}. * @throws NullPointerException If given argument is {@code null} */ static int call(@Nonnull final BiLongToIntFunction function, long value1, long value2) { Objects.requireNonNull(function); return function.applyAsInt(value1, value2); } /** * Creates a {@link BiLongToIntFunction} which uses the {@code first} parameter of this one as argument for the * given {@link LongToIntFunction}. * * @param function The function which accepts the {@code first} parameter of this one * @return Creates a {@code BiLongToIntFunction} which uses the {@code first} parameter of this one as argument for * the given {@code LongToIntFunction}. * @throws NullPointerException If given argument is {@code null} */ @Nonnull static BiLongToIntFunction onlyFirst(@Nonnull final LongToIntFunction function) { Objects.requireNonNull(function); return (value1, value2) -> function.applyAsInt(value1); } /** * Creates a {@link BiLongToIntFunction} which uses the {@code second} parameter of this one as argument for the * given {@link LongToIntFunction}. * * @param function The function which accepts the {@code second} parameter of this one * @return Creates a {@code BiLongToIntFunction} which uses the {@code second} parameter of this one as argument for * the given {@code LongToIntFunction}. * @throws NullPointerException If given argument is {@code null} */ @Nonnull static BiLongToIntFunction onlySecond(@Nonnull final LongToIntFunction function) { Objects.requireNonNull(function); return (value1, value2) -> function.applyAsInt(value2); } /** * Creates a {@link BiLongToIntFunction} which always returns a given value. * * @param ret The return value for the constant * @return A {@code BiLongToIntFunction} which always returns a given value. */ @Nonnull static BiLongToIntFunction constant(int ret) { return (value1, value2) -> ret; } /** * Applies this function to the given arguments. * * @param value1 The first argument to the function * @param value2 The second argument to the function * @return The return value from the function, which is its result. */ int applyAsInt(long value1, long value2); /** * Applies this function partially to some arguments of this one, producing a {@link LongToIntFunction2} as result. * * @param value1 The first argument to this function used to partially apply this function * @return A {@code LongToIntFunction2} that represents this function partially applied the some arguments. */ @Nonnull default LongToIntFunction2 papplyAsInt(long value1) { return (value2) -> this.applyAsInt(value1, value2); } /** * 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 ToIntBiFunction2} 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 ToIntBiFunction2} 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> ToIntBiFunction2<A, B> compose(@Nonnull final ToLongFunction<? super A> before1, @Nonnull final ToLongFunction<? super B> before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (a, b) -> applyAsInt(before1.applyAsLong(a), before2.applyAsLong(b)); } /** * Returns a composed {@link BiBooleanToIntFunction} 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 BiBooleanToIntFunction} 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 BiBooleanToIntFunction composeFromBoolean(@Nonnull final BooleanToLongFunction before1, @Nonnull final BooleanToLongFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link BiByteToIntFunction} 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 BiByteToIntFunction} 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 BiByteToIntFunction composeFromByte(@Nonnull final ByteToLongFunction before1, @Nonnull final ByteToLongFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link BiCharToIntFunction} 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 BiCharToIntFunction} 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 BiCharToIntFunction composeFromChar(@Nonnull final CharToLongFunction before1, @Nonnull final CharToLongFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link BiDoubleToIntFunction} 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 function to apply before this function is applied * @return A composed {@code BiDoubleToIntFunction} 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 BiDoubleToIntFunction composeFromDouble(@Nonnull final DoubleToLongFunction before1, @Nonnull final DoubleToLongFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link BiFloatToIntFunction} 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 BiFloatToIntFunction} 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 BiFloatToIntFunction composeFromFloat(@Nonnull final FloatToLongFunction before1, @Nonnull final FloatToLongFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link IntBinaryOperator2} 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 IntBinaryOperator2} 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 IntBinaryOperator2 composeFromInt(@Nonnull final IntToLongFunction before1, @Nonnull final IntToLongFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link BiLongToIntFunction} that first applies the {@code before} operators 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 operator to apply before this function is applied * @param before2 The second operator to apply before this function is applied * @return A composed {@code BiLongToIntFunction} that first applies the {@code before} operators 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 BiLongToIntFunction composeFromLong(@Nonnull final LongUnaryOperator before1, @Nonnull final LongUnaryOperator before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link BiShortToIntFunction} 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 BiShortToIntFunction} 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 BiShortToIntFunction composeFromShort(@Nonnull final ShortToLongFunction before1, @Nonnull final ShortToLongFunction before2) { Objects.requireNonNull(before1); Objects.requireNonNull(before2); return (value1, value2) -> applyAsInt(before1.applyAsLong(value1), before2.applyAsLong(value2)); } /** * Returns a composed {@link BiLongFunction} 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 BiLongFunction} 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> BiLongFunction<S> andThen(@Nonnull final IntFunction<? extends S> after) { Objects.requireNonNull(after); return (value1, value2) -> after.apply(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongPredicate} 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 BiLongPredicate} 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 BiLongPredicate andThenToBoolean(@Nonnull final IntPredicate after) { Objects.requireNonNull(after); return (value1, value2) -> after.test(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongToByteFunction} 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 BiLongToByteFunction} 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 BiLongToByteFunction andThenToByte(@Nonnull final IntToByteFunction after) { Objects.requireNonNull(after); return (value1, value2) -> after.applyAsByte(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongToCharFunction} 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 BiLongToCharFunction} 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 BiLongToCharFunction andThenToChar(@Nonnull final IntToCharFunction after) { Objects.requireNonNull(after); return (value1, value2) -> after.applyAsChar(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongToDoubleFunction} 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 double}. * * @param after The function to apply after this function is applied * @return A composed {@code BiLongToDoubleFunction} 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 * double}. */ @Nonnull default BiLongToDoubleFunction andThenToDouble(@Nonnull final IntToDoubleFunction after) { Objects.requireNonNull(after); return (value1, value2) -> after.applyAsDouble(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongToFloatFunction} 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 BiLongToFloatFunction} 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 BiLongToFloatFunction andThenToFloat(@Nonnull final IntToFloatFunction after) { Objects.requireNonNull(after); return (value1, value2) -> after.applyAsFloat(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongToIntFunction} 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 int}. * * @param after The operator to apply after this function is applied * @return A composed {@code BiLongToIntFunction} 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 * int}. */ @Nonnull default BiLongToIntFunction andThenToInt(@Nonnull final IntUnaryOperator after) { Objects.requireNonNull(after); return (value1, value2) -> after.applyAsInt(applyAsInt(value1, value2)); } /** * Returns a composed {@link LongBinaryOperator2} 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 LongBinaryOperator2} 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 LongBinaryOperator2 andThenToLong(@Nonnull final IntToLongFunction after) { Objects.requireNonNull(after); return (value1, value2) -> after.applyAsLong(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongToShortFunction} 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 BiLongToShortFunction} 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 BiLongToShortFunction andThenToShort(@Nonnull final IntToShortFunction after) { Objects.requireNonNull(after); return (value1, value2) -> after.applyAsShort(applyAsInt(value1, value2)); } /** * Returns a composed {@link BiLongConsumer} that fist applies this function to its input, and then consumes the * result using the given {@link IntConsumer}. 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 BiLongConsumer} that first applies this function to its input, and then consumes the * result using the given {@code IntConsumer}. * @throws NullPointerException If given argument is {@code null} */ @Nonnull default BiLongConsumer consume(@Nonnull final IntConsumer consumer) { Objects.requireNonNull(consumer); return (value1, value2) -> consumer.accept(applyAsInt(value1, value2)); } /** * Returns a memoized (caching) version of this {@link BiLongToIntFunction}. 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 BiLongToIntFunction}. * @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 BiLongToIntFunction memoized() { if (isMemoized()) { return this; } else { final Map<Pair<Long, Long>, Integer> cache = new ConcurrentHashMap<>(); final Object lock = new Object(); return (BiLongToIntFunction & Memoized) (value1, value2) -> { final int returnValue; synchronized (lock) { returnValue = cache.computeIfAbsent(Pair.of(value1, value2), key -> applyAsInt(key.getLeft(), key.getRight())); } return returnValue; }; } } /** * Returns a composed {@link BiFunction2} which represents this {@link BiLongToIntFunction}. Thereby the primitive * input argument for this function is autoboxed. This method provides the possibility to use this * {@code BiLongToIntFunction} with methods provided by the {@code JDK}. * * @return A composed {@code BiFunction2} which represents this {@code BiLongToIntFunction}. */ @Nonnull default BiFunction2<Long, Long, Integer> boxed() { return this::applyAsInt; } }