org.apache.clerezza.scala.utils.EzMGraph.scala Maven / Gradle / Ivy

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/*
 * 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.clerezza.scala.utils

import org.apache.clerezza
import org.apache.clerezza._
import org.apache.clerezza.implementation.graph.AbstractGraph
import org.apache.clerezza.implementation.in_memory.SimpleGraph

import _root_.scala.collection.mutable.HashMap


/**
  * EzGraph enhances graph writing, it can make writing rdf graphs in code a lot more
  * readable, as it avoids a lot of repetition.
  *
  * @param graph : a Triple collection
  * @author hjs, reto
  */
class EzGraph(val baseTc: Graph) extends AbstractGraph with TcDependentConversions {


    def this() = this(new SimpleGraph())

    def performFilter(subject: BlankNodeOrIRI, predicate: IRI,
                      obj: RDFTerm): java.util.Iterator[clerezza.Triple] = baseTc.filter(subject, predicate, obj)

    override def performSize = baseTc.size

    override def add(t: clerezza.Triple) = baseTc.add(t)

    /**
      * Add all triples into the other graph to this one
      */
    def +=(other: Graph) = {
        if (baseTc ne other) baseTc.addAll(other)
    }

    /**
      * create a new bnode
      */
    def bnode = blankNode

    def blankNode: BlankNode = {
        new BlankNode
    }

    private val namedBnodes = new HashMap[String, BlankNode]

    /**
      * create a new named bnode based EzGraphNode with the preferred writing style
      */
    def b_(name: String): BlankNode = {
        namedBnodes.get(name) match {
            case Some(bnode) => bnode
            case None => {
                val bn = new BlankNode
                namedBnodes.put(name, bn);
                bn
            }
        }
    }

}