001    /*
002     * Copyright (C) 2011 The Guava Authors
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005     * in compliance with the License. You may obtain a copy of the License at
006     *
007     * http://www.apache.org/licenses/LICENSE-2.0
008     *
009     * Unless required by applicable law or agreed to in writing, software distributed under the License
010     * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011     * or implied. See the License for the specific language governing permissions and limitations under
012     * the License.
013     */
014    
015    package com.google.common.collect;
016    
017    import com.google.common.annotations.Beta;
018    import com.google.common.annotations.GwtCompatible;
019    
020    /**
021     * Indicates whether an endpoint of some range is contained in the range itself ("closed") or not
022     * ("open"). If a range is unbounded on a side, it is neither open nor closed on that side; the
023     * bound simply does not exist.
024     *
025     * @since 10.0
026     */
027    @Beta
028    @GwtCompatible
029    public enum BoundType {
030      /**
031       * The endpoint value <i>is not</i> considered part of the set ("exclusive").
032       */
033      OPEN {
034        @Override
035        BoundType flip() {
036          return CLOSED;
037        }
038      },
039      /**
040       * The endpoint value <i>is</i> considered part of the set ("inclusive").
041       */
042      CLOSED {
043        @Override
044        BoundType flip() {
045          return OPEN;
046        }
047      };
048    
049      /**
050       * Returns the bound type corresponding to a boolean value for inclusivity.
051       */
052      static BoundType forBoolean(boolean inclusive) {
053        return inclusive ? CLOSED : OPEN;
054      }
055    
056      abstract BoundType flip();
057    }