001    /*
002     * Copyright 2010-2013 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.jet.util.slicedmap;
018    
019    import java.util.Collection;
020    import java.util.Collections;
021    import java.util.Iterator;
022    import java.util.Map;
023    
024    public interface SlicedMap extends Iterable<Map.Entry<SlicedMapKey<?, ?>, ?>> {
025    
026        SlicedMap DO_NOTHING = new SlicedMap() {
027            @Override
028            public <K, V> V get(ReadOnlySlice<K, V> slice, K key) {
029                return slice.computeValue(this, key, null, true);
030            }
031    
032            @Override
033            public <K, V> Collection<K> getKeys(WritableSlice<K, V> slice) {
034                return Collections.emptySet();
035            }
036    
037            @Override
038            public Iterator<Map.Entry<SlicedMapKey<?, ?>, ?>> iterator() {
039                return Collections.<Map.Entry<SlicedMapKey<?, ?>, ?>>emptySet().iterator();
040            }
041        };
042    
043        <K, V> V get(ReadOnlySlice<K, V> slice, K key);
044    
045        // slice.isCollective() must return true
046        <K, V> Collection<K> getKeys(WritableSlice<K, V> slice);
047    }