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// SPDX-License-Identifier: Apache-2.0
/*
* extended-functions
* Copyright 2021-2024 Marko Zajc
*
* 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 org.eu.zajc.ef.unary;
import java.util.Objects;
import java.util.function.UnaryOperator;
import javax.annotation.Nonnull;
import org.eu.zajc.ef.binary.BooleanBinaryOperator;
/**
* Represents an operation on a single {@code boolean}-valued operand that produces
* an {@code boolean}-valued result. This is the primitive type specialization of
* {@link UnaryOperator} for {@code boolean}.
*
*
* This is a functional interface whose functional method is
* {@link #applyAsBoolean(boolean)}.
*
* @see UnaryOperator
* @see BooleanBinaryOperator
*
* @author Marko Zajc
*/
public interface BooleanUnaryOperator {
/**
* Applies this operator to the given operand.
*
* @param operand
* the operand
*
* @return the operator result
*/
boolean applyAsBoolean(boolean operand);
/**
* Returns a composed operator that first applies the {@code before} operator to its
* input, and then applies this operator to the result. If evaluation of either
* operator throws an exception, it is relayed to the caller of the composed
* operator.
*
* @param before
* the operator to apply before this operator is applied
*
* @return a composed operator that first applies the {@code before} operator and
* then applies this operator
*
* @throws NullPointerException
* if before is null
*
* @see #andThen(BooleanUnaryOperator)
*/
@Nonnull
default BooleanUnaryOperator compose(@Nonnull BooleanUnaryOperator before) {
Objects.requireNonNull(before);
return (boolean v) -> applyAsBoolean(before.applyAsBoolean(v));
}
/**
* Returns a composed operator that first applies this operator to its input, and
* then applies the {@code after} operator to the result. If evaluation of either
* operator throws an exception, it is relayed to the caller of the composed
* operator.
*
* @param after
* the operator to apply after this operator is applied
*
* @return a composed operator that first applies this operator and then applies the
* {@code after} operator
*
* @throws NullPointerException
* if after is null
*
* @see #compose(BooleanUnaryOperator)
*/
@Nonnull
default BooleanUnaryOperator andThen(@Nonnull BooleanUnaryOperator after) {
Objects.requireNonNull(after);
return (boolean t) -> after.applyAsBoolean(applyAsBoolean(t));
}
/**
* Returns a unary operator that always returns its input argument.
*
* @return a unary operator that always returns its input argument
*/
@Nonnull
static BooleanUnaryOperator identity() {
return t -> t;
}
}