de.flapdoodle.guava.Flatter.java Source code

Introduction

Here is the source code for de.flapdoodle.guava.Flatter.java

Source

/**
 * Copyright (C) 2013
 *   Michael Mosmann <michael@mosmann.de>
 *
 * 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 de.flapdoodle.guava;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;

public abstract class Flatter {

    private Flatter() {
        // no instance
    }

    public static <P, T> Function<? super P, Iterable<? extends Flat<P, T>>> flat(
            final Function<? super P, ? extends Iterable<? extends T>> sub) {
        return new Function<P, Iterable<? extends Flat<P, T>>>() {

            @Override
            public Iterable<? extends Flat<P, T>> apply(final P parent) {
                return Iterables.transform(sub.apply(parent), new Function<T, Flat<P, T>>() {
                    public Flat<P, T> apply(T value) {
                        return new Flat<P, T>(parent, value);
                    };
                });
            }

        };
    }

    public static <A, P, T> Function<? super Flat<A, P>, Iterable<? extends Flat<Flat<A, P>, T>>> flatted(
            final Function<? super P, ? extends Iterable<? extends T>> sub) {
        return new Function<Flat<A, P>, Iterable<? extends Flat<Flat<A, P>, T>>>() {

            @Override
            public Iterable<? extends Flat<Flat<A, P>, T>> apply(final Flat<A, P> parent) {
                return Iterables.transform(sub.apply(parent.value()), new Function<T, Flat<Flat<A, P>, T>>() {
                    public Flat<Flat<A, P>, T> apply(T value) {
                        return new Flat<Flat<A, P>, T>(parent, value);
                    };
                });
            }

        };
    }
}