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.utils;
018    
019    import org.jetbrains.annotations.NotNull;
020    import org.jetbrains.annotations.Nullable;
021    
022    public class Nulls {
023        private static final Object NULL_VALUE = new Object();
024    
025        @Nullable
026        @SuppressWarnings("unchecked")
027        public static <V> V unescape(@NotNull Object value) {
028            if (value == NULL_VALUE) return null;
029            return (V) value;
030        }
031    
032        @NotNull
033        public static <V> Object escape(@Nullable V value) {
034            if (value == null) return NULL_VALUE;
035            return value;
036        }
037    }