Examples with LongToIntFunction java.util.function.LongToIntFunction used on opensource projects

Example 1 with LongToIntFunction

use of java.util.function.LongToIntFunction in project MindsEye by SimiaCryptus.

the class TestUtil method shuffle.

/**
 * Shuffle int stream.
 *
 * @param stream the stream
 * @return the int stream
 */
public static IntStream shuffle(@Nonnull IntStream stream) {
    // http://primes.utm.edu/lists/small/10000.txt
    long coprimeA = 41387;
    long coprimeB = 9967;
    long ringSize = coprimeA * coprimeB - 1;
    @Nonnull IntToLongFunction fn = x -> (x * coprimeA * coprimeA) % ringSize;
    @Nonnull LongToIntFunction inv = x -> (int) ((x * coprimeB * coprimeB) % ringSize);
    @Nonnull IntUnaryOperator conditions = x -> {
        assert x < ringSize;
        assert x >= 0;
        return x;
    };
    return stream.map(conditions).mapToLong(fn).sorted().mapToInt(inv);
}