/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.commons.collections4.functors;

import org.apache.commons.collections4.Closure;
import org.apache.commons.collections4.Predicate;

Closure implementation that executes a closure repeatedly until a condition is met,
like a do-while or while loop.

WARNING: from v4.1 onwards this class will not be serializable anymore
in order to prevent potential remote code execution exploits. Please refer to
COLLECTIONS-580
for more details.

Since:
3.0/**
 * Closure implementation that executes a closure repeatedly until a condition is met,
 * like a do-while or while loop.
 * <p>
 * <b>WARNING:</b> from v4.1 onwards this class will <b>not</b> be serializable anymore
 * in order to prevent potential remote code execution exploits. Please refer to
 * <a href="https://issues.apache.org/jira/browse/COLLECTIONS-580">COLLECTIONS-580</a>
 * for more details.
 * </p>
 *
 * @since 3.0
 */
public class WhileClosure<E> implements Closure<E> {

    
The test condition /** The test condition */
    private final Predicate<? super E> iPredicate;
    
The closure to call /** The closure to call */
    private final Closure<? super E> iClosure;
    
The flag, true is a do loop, false is a while /** The flag, true is a do loop, false is a while */
    private final boolean iDoLoop;

    
Factory method that performs validation.
Params:
predicate –  the predicate used to evaluate when the loop terminates, not null
closure –  the closure the execute, not null
doLoop –  true to act as a do-while loop, always executing the closure once
Type parameters:
<E> – the type that the closure acts on
Throws:
NullPointerException – if the predicate or closure is null
Returns:
the while closure/**
     * Factory method that performs validation.
     *
     * @param <E> the type that the closure acts on
     * @param predicate  the predicate used to evaluate when the loop terminates, not null
     * @param closure  the closure the execute, not null
     * @param doLoop  true to act as a do-while loop, always executing the closure once
     * @return the <code>while</code> closure
     * @throws NullPointerException if the predicate or closure is null
     */
    public static <E> Closure<E> whileClosure(final Predicate<? super E> predicate,
                                              final Closure<? super E> closure, final boolean doLoop) {
        if (predicate == null) {
            throw new NullPointerException("Predicate must not be null");
        }
        if (closure == null) {
            throw new NullPointerException("Closure must not be null");
        }
        return new WhileClosure<>(predicate, closure, doLoop);
    }

    
Constructor that performs no validation.
Use whileClosure if you want that.
Params:
predicate –  the predicate used to evaluate when the loop terminates, not null
closure –  the closure the execute, not null
doLoop –  true to act as a do-while loop, always executing the closure once/**
     * Constructor that performs no validation.
     * Use <code>whileClosure</code> if you want that.
     *
     * @param predicate  the predicate used to evaluate when the loop terminates, not null
     * @param closure  the closure the execute, not null
     * @param doLoop  true to act as a do-while loop, always executing the closure once
     */
    public WhileClosure(final Predicate<? super E> predicate, final Closure<? super E> closure, final boolean doLoop) {
        super();
        iPredicate = predicate;
        iClosure = closure;
        iDoLoop = doLoop;
    }

    
Executes the closure until the predicate is false.
Params:
input –  the input object/**
     * Executes the closure until the predicate is false.
     *
     * @param input  the input object
     */
    @Override
    public void execute(final E input) {
        if (iDoLoop) {
            iClosure.execute(input);
        }
        while (iPredicate.evaluate(input)) {
            iClosure.execute(input);
        }
    }

    
Gets the predicate in use.
Returns:
the predicate
Since:
3.1/**
     * Gets the predicate in use.
     *
     * @return the predicate
     * @since 3.1
     */
    public Predicate<? super E> getPredicate() {
        return iPredicate;
    }

    
Gets the closure.
Returns:
the closure
Since:
3.1/**
     * Gets the closure.
     *
     * @return the closure
     * @since 3.1
     */
    public Closure<? super E> getClosure() {
        return iClosure;
    }

    
Is the loop a do-while loop.
Returns:
true is do-while, false if while
Since:
3.1/**
     * Is the loop a do-while loop.
     *
     * @return true is do-while, false if while
     * @since 3.1
     */
    public boolean isDoLoop() {
        return iDoLoop;
    }

}