Ntriples.php

1. 8.x drupal/core/vendor/easyrdf/easyrdf/lib/EasyRdf/Parser/Ntriples.php
2. 8.x drupal/core/vendor/easyrdf/easyrdf/lib/EasyRdf/Serialiser/Ntriples.php

<?php

/**
 * EasyRdf
 *
 * LICENSE
 *
 * Copyright (c) 2009-2012 Nicholas J Humfrey.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author 'Nicholas J Humfrey" may be used to endorse or
 *    promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * @package    EasyRdf
 * @copyright  Copyright (c) 2009-2012 Nicholas J Humfrey
 * @license    http://www.opensource.org/licenses/bsd-license.php
 * @version    $Id$
 */

/**
 * A pure-php class to parse N-Triples with no dependancies.
 *
 * @package    EasyRdf
 * @copyright  Copyright (c) 2009-2012 Nicholas J Humfrey
 * @license    http://www.opensource.org/licenses/bsd-license.php
 */
class EasyRdf_Parser_Ntriples extends EasyRdf_Parser {

  /**
   * Decodes an encoded N-Triples string. Any \-escape sequences are substituted
   * with their decoded value.
   *
   * @param  string $str An encoded N-Triples string.
   * @return The unencoded string.
   **/
  protected function unescapeString($str) {
    if (strpos($str, '\\') === false) {
      return $str;
    }
    $mappings = array(
      't' => chr(0x9),
      'b' => chr(0x8),
      'n' => chr(0xa),
      'r' => chr(0xd),
      'f' => chr(0xc),
      '\\"' => chr(0x22),
      '\'' => chr(0x27),
    );
    foreach ($mappings as $in => $out) {
      $str = preg_replace('/\\x5c([' . $in . '])/', $out, $str);
    }
    if (stripos($str, '\\u') === false) {
      return $str;
    }
    while (preg_match('/\\\\(U)([0-9A-F]{8})/', $str, $matches) || preg_match('/\\\\(u)([0-9A-F]{4})/', $str, $matches)) {
      $no = hexdec($matches[2]);
      if ($no < 128) {
        $char = chr($no);
      }
      elseif ($no < 2048) {
        $char = chr(($no >> 6) + 192) . chr(($no & 63) + 128);
      }
      elseif ($no < 65536) {
        $char = chr(($no >> 12) + 224) . chr(($no >> 6 & 63) + 128) . chr(($no & 63) + 128);
      }
      elseif ($no < 2097152) {
        $char = chr(($no >> 18) + 240) . chr(($no >> 12 & 63) + 128) . chr(($no >> 6 & 63) + 128) . chr(($no & 63) + 128);
      }
      else {
        $char = '';
      }
      $str = str_replace('\\' . $matches[1] . $matches[2], $char, $str);
    }
    return $str;
  }

  /**
   * @ignore
   */
  protected function parseNtriplesSubject($sub) {
    if (preg_match('/<([^<>]+)>/', $sub, $matches)) {
      return $this
        ->unescapeString($matches[1]);
    }
    elseif (preg_match('/_:([A-Za-z0-9]*)/', $sub, $matches)) {
      if (empty($matches[1])) {
        return $this->graph
          ->newBNodeId();
      }
      else {
        $nodeid = $this
          ->unescapeString($matches[1]);
        return $this
          ->remapBnode($nodeid);
      }
    }
    else {
      throw new EasyRdf_Exception("Failed to parse subject: {$sub}");
    }
  }

  /**
   * @ignore
   */
  protected function parseNtriplesObject($obj) {
    if (preg_match('/"(.+)"\\^\\^<([^<>]+)>/', $obj, $matches)) {
      return array(
        'type' => 'literal',
        'value' => $this
          ->unescapeString($matches[1]),
        'datatype' => $this
          ->unescapeString($matches[2]),
      );
    }
    elseif (preg_match('/"(.+)"@([\\w\\-]+)/', $obj, $matches)) {
      return array(
        'type' => 'literal',
        'value' => $this
          ->unescapeString($matches[1]),
        'lang' => $this
          ->unescapeString($matches[2]),
      );
    }
    elseif (preg_match('/"(.*)"/', $obj, $matches)) {
      return array(
        'type' => 'literal',
        'value' => $this
          ->unescapeString($matches[1]),
      );
    }
    elseif (preg_match('/<([^<>]+)>/', $obj, $matches)) {
      return array(
        'type' => 'uri',
        'value' => $matches[1],
      );
    }
    elseif (preg_match('/_:([A-Za-z0-9]*)/', $obj, $matches)) {
      if (empty($matches[1])) {
        return array(
          'type' => 'bnode',
          'value' => $this->graph
            ->newBNodeId(),
        );
      }
      else {
        $nodeid = $this
          ->unescapeString($matches[1]);
        return array(
          'type' => 'bnode',
          'value' => $this
            ->remapBnode($nodeid),
        );
      }
    }
    else {
      throw new EasyRdf_Exception("Failed to parse object: {$obj}");
    }
  }

  /**
   * Parse an N-Triples document into an EasyRdf_Graph
   *
   * @param object EasyRdf_Graph $graph   the graph to load the data into
   * @param string               $data    the RDF document data
   * @param string               $format  the format of the input data
   * @param string               $baseUri the base URI of the data being parsed
   * @return integer             The number of triples added to the graph
   */
  public function parse($graph, $data, $format, $baseUri) {
    parent::checkParseParams($graph, $data, $format, $baseUri);
    if ($format != 'ntriples') {
      throw new EasyRdf_Exception("EasyRdf_Parser_Ntriples does not support: {$format}");
    }
    $lines = preg_split("/[\r\n]+/", strval($data));
    foreach ($lines as $line) {
      if (preg_match("/^\\s*#/", $line)) {
        continue;
      }
      elseif (preg_match("/(.+)\\s+<([^<>]+)>\\s+(.+)\\s*\\./", $line, $matches)) {
        $this
          ->addTriple($this
          ->parseNtriplesSubject($matches[1]), $this
          ->unescapeString($matches[2]), $this
          ->parseNtriplesObject($matches[3]));
      }
    }
    return $this->tripleCount;
  }

}