com.facebook.buck.rules.coercer.MapConcatenatingCoercer.java Source code

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Here is the source code for com.facebook.buck.rules.coercer.MapConcatenatingCoercer.java

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/*
 * Copyright 2018-present Facebook, Inc.
 *
 * 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.buck.rules.coercer;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

class MapConcatenatingCoercer extends JsonTypeConcatenatingCoercer {

    MapConcatenatingCoercer() {
        super(Map.class);
    }

    @Override
    public Object concat(Iterable<Object> elements) {
        @SuppressWarnings("unchecked")
        Iterable<Set<Entry<Object, Object>>> maps = Iterables.transform(elements,
                map -> ((Map<Object, Object>) map).entrySet());
        return ImmutableMap.copyOf(Iterables.concat(maps));
    }
}