com.facebook.presto.util.MapTransformer.java Source code

Introduction

Here is the source code for com.facebook.presto.util.MapTransformer.java

Source

/*
 * 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 com.facebook.presto.util;

import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.collect.BiMap;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;

import java.util.Map;

public class MapTransformer<K, V> {
    private final Map<K, V> map;

    public static <K, V> MapTransformer<K, V> of(Map<K, V> map) {
        return new MapTransformer<>(map);
    }

    public MapTransformer(Map<K, V> map) {
        this.map = map;
    }

    public <V1> MapTransformer<K, V1> transformValues(Function<V, V1> function) {
        return new MapTransformer<>(Maps.transformValues(map, function));
    }

    public MapTransformer<K, V> filterValues(Predicate<? super V> predicate) {
        return new MapTransformer<>(Maps.filterValues(map, predicate));
    }

    public <V1 extends V> MapTransformer<K, V1> castValues(Class<V1> clazz) {
        return transformValues(MoreFunctions.<V, V1>cast(clazz));
    }

    public Map<K, V> map() {
        return map;
    }

    public MapTransformer<V, K> inverse() {
        return new MapTransformer<>(ImmutableBiMap.copyOf(map).inverse());
    }

    public BiMap<K, V> biMap() {
        return ImmutableBiMap.copyOf(map);
    }

    public Map<K, V> immutableMap() {
        return ImmutableMap.copyOf(map);
    }
}