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ixjava developed by David Karnok

There is a newer version: 1.0.0

/*
 * Copyright 2011-2016 David Karnok
 *
 * 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 ix;

import java.util.Iterator;

final class IxZipArray extends Ix {

    final Iterable[] sources;

    final IxFunction zipper;

    IxZipArray(Iterable[] sources, IxFunction zipper) {
        this.sources = sources;
        this.zipper = zipper;
    }

    @SuppressWarnings("unchecked")
    @Override
    public Iterator iterator() {

        Iterable[] src = sources;

        Iterator[] iterators = new Iterator[src.length];
        for (int i = 0; i < iterators.length; i++) {
            iterators[i] = (Iterator)src[i].iterator();
        }

        return new ZipArrayIterator(iterators, zipper);
    }

    static final class ZipArrayIterator extends IxBaseIterator {

        final Iterator[] sources;

        final IxFunction zipper;

        ZipArrayIterator(Iterator[] sources, IxFunction zipper) {
            this.sources = sources;
            this.zipper = zipper;
        }

        @SuppressWarnings("unchecked")
        @Override
        protected boolean moveNext() {
            Iterator[] iterators = sources;
            int n = iterators.length;
            T[] a = (T[])new Object[n];

            for (int i = 0; i < n; i++) {
                Iterator it = iterators[i];
                if (it.hasNext()) {
                    a[i] = it.next();
                } else {
                    done = true;
                    return false;
                }
            }

            value = zipper.apply(a);
            hasValue = true;

            return true;
        }

    }

}