/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.tinkerpop.gremlin.structure;
import org.apache.tinkerpop.gremlin.process.traversal.Path;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.function.Function;
/**
* Column references a particular type of column in a complex data structure such as a {@link java.util.Map}, a {@link java.util.Map.Entry}, or a {@link org.apache.tinkerpop.gremlin.process.traversal.Path}.
*
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public enum Column implements Function<Object, Object> {
/**
* The keys associated with the data structure.
*/
keys {
@Override
public Object apply(final Object object) {
if (object instanceof Map)
return new LinkedHashSet<>(((Map<?,?>) object).keySet());
else if (object instanceof Map.Entry)
return ((Map.Entry) object).getKey();
else if (object instanceof Path)
return new ArrayList<>(((Path) object).labels());
else
throw new IllegalArgumentException("The provided object does not have accessible keys: " + object.getClass());
}
},
/**
* The values associated with the data structure.
*/
values {
@Override
public Object apply(final Object object) {
if (object instanceof Map)
return new ArrayList<>(((Map<?,?>) object).values());
else if (object instanceof Map.Entry)
return ((Map.Entry) object).getValue();
else if (object instanceof Path)
return new ArrayList<>(((Path) object).objects());
else
throw new IllegalArgumentException("The provided object does not have accessible keys: " + object.getClass());
}
}
}