N3Parser.php | searchcode

/lib/rdfapi-php/api/syntax/N3Parser.php

https://github.com/komagata/plnet
PHP | 1052 lines | 844 code | 78 blank | 130 comment | 42 complexity | d8a23eace8180640385702a1ff86ad33 MD5 | raw file
Possible License(s): LGPL-2.1

<?php



// ----------------------------------------------------------------------------------

// Class: N3Parser

// ----------------------------------------------------------------------------------





/**

 * PHP Notation3 Parser 

 * 

 * This parser can parse a subset of n3, reporting triples to a callback function 

 * or constructing a RAP Model ( http://www.wiwiss.fu-berlin.de/suhl/bizer/rdfapi )

 * 

 * Supported N3 features: 

 * <ul>

 *   <li>Standard things, repeated triples ( ; and , ), blank nodes using [ ], self-reference ('<>')</li>

 *   <li>@prefix mappings</li>

 *   <li>= maps to owl#sameAs</li>

 *   <li>a maps to rdf-syntax-ns#type</li>

 *   <li>Literal datytype- and xmlLanguageTag support 

 * </ul>

 * Un-supported N3 Features include: 

 * <ul>

 *   <li>Reification using { }</li>

 *   <li>. and ^ operators for tree traversal</li>

 *   <li>Any log operators, like log:forAll etc.</li>

 * </ul>

 *

 * This parser is based on n3.py from Epp released 2nd March, 2002. 

 * by Sean B. Palmer 

 * ( http://infomesh.net/2002/eep/20020302-013802/n3.py )

 * 

 * This parser is released under the GNU GPL license.

 * ( http://www.gnu.org/licenses/gpl.txt ) 

 * 

 *

 *

 * @author Sean B. Palmer <sean@mysterylights.com>, Gunnar AA. Grimnes <ggrimnes@csd.abdn.ac.uk>, Daniel Westphal <mail@d-westphal.de>

 * @version $Id: N3Parser.php,v 1.25 2006/05/15 05:24:36 tgauss Exp $

 * @package syntax

 * @access public

 **/



class N3Parser extends Object {





  /* ==================== Variables ==================== */



  var $Tokens;

  var $bNode;

  var $RDF_NS, $DAML_NS, $OWL_NS;

  var $debug;

  var $parseError;

  var $parsedNamespaces = array();



  /* ==================== Public Methods ==================== */



  /** 

   * Constructor 

   * @access public

   **/

  function N3Parser() { 

    //Regular expressions:

     $Name = '[A-Za-z0-9_@\.]+[^\.,;\[\] ]*';

     $URI = '<[^> ]*>';

     $bNode = '_:'.$Name;

     $Univar = '\?'.$Name;

     $QName = '(?:[A-Za-z][A-Za-z0-9_@\.]*)?:'.$Name;

     $Literal = '"(\\\"|[^"])*"'; # '"(?:\\"|[^"])*"'

//   $Literal = '"[^"\\\\]*(?:\\.\\[^"\\]*)*"'; # '"(?:\\"|[^"])*"'

     $LangTag = '@[A-Za-z\-]*[^ \^\.\;\,]';

     $Datatype = '(\^\^)[^ ,\.;)]+';

     $Datatype_URI = '(\^\^)'.$URI;  

     //     $LLiteral = '"""[^"\\\\]*(?:(?:.|"(?!""))[^"\\\\]*)*"""';

     $LLiteral = '"""[^"\\\\]*(?:(?:\\\\.|"(?!""))[^"\\\\]*)*"""';

     //          '"""[^"\\]*(?:(?:\\.|"(?!""))[^"\\]*)*"""'

     $Comment = '# .*$';

     $Prefix = '(?:[A-Za-z][A-Za-z0-9_]*)?:';

     $PrefixDecl = '@prefix';

     $WS = '[ \t]';

     $this->RDF_NS = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'; # for 'a' keyword

     $this->DAML_NS = 'http://www.daml.org/2001/03/daml+oil#'; # for '=' keyword

     $this->OWL_NS = 'http://www.w3.org/2002/07/owl#';



     //     $t = array( $LLiteral, $URI); //, $Literal, $PrefixDecl, $QName, $bNode, $Prefix,     

     //	    $Univar, 'a', '{', '}', '\(', '\)', '\[', '\]', ',', ';', '\.', $WS, $Comment);

     $t = array( $Datatype_URI,$Datatype,$LLiteral, $URI, $Literal, $PrefixDecl, $QName, $bNode, $Prefix, $Univar, 'a','=', '{', '}', '\(', '\)', '\[', '\]', ',', ';', '\.', $WS, $Comment,$LangTag);

     $this->Tokens="/(".join($t,"|").")/m";



     $this->bNode=0;

     $this->debug=0;

     $this->bNodeMap = array();

     $this->FixBnodes = FIX_BLANKNODES;

     $this->parseError=false;

  }

  



  /** 

   * Sets, if BlankNode labels should be replaced by the generic label from the constants.php file  

   * default is "false" -> the used label in n3 is parsed to the model

   * @param boolean

   * @access public 

   **/

  function setFixBnodes($set) {



  	if (($set===true) OR ($set===false)) $this->FixBnodes = $set;

  }

  

  

  /** 

   * This parses a N3 string and prints out the triples 

   * @param string $s

   * @access public 

   **/

  function parse($s) {

    //   """Get a string, tokenize, create list, convert to Eep store."""

    $stat=$this->n3tolist($s);

    foreach ( $stat as $t) { 



      if (count($t)>3) {           

        $object=$t[2];



        for ($i = 3; $i < 5; $i++){

          if ($t[$i][0]=='@')$object.=$t[$i];

          if (substr($t[$i],0,2)=='^^')$object.=$t[$i];                            

        };

      } else {$object=$t[2];};

         

      print '('.$t[0].', '.$t[1].', '.$object.")\n";



    }

    //   return [[eep.Article(t[0]), eep.Article(t[1]), eep.Article(t[2])] 

    //              for t in n3tolist(s)]

  }



  

  /** 

   * This parses a N3 string and calls func($subject, $predicate, $object) with each trioke

   * @param string $s

   * @param string $func

   * @access public 

   **/

  function uparse($s,$func) {

    //   """Get a string, tokenize, create list, convert to Eep store."""

    $stat=$this->n3tolist($s);

    foreach ( $stat as $t) { 



    	if (count($t)>3) {           

        $object=$t[2];



        for ($i = 3; $i < 5; $i++){

          if ($t[$i][0]=='@')$object.=$t[$i];

          if (substr($t[$i],0,2)=='^^')$object.=$t[$i];                            

        };

      } else {$object=$t[2];};

    	//    print "(".$t[0].", ".$t[1].", ".$t[2].")";

      

      $func($t[0],$t[1],$object);

    }

    //   return [[eep.Article(t[0]), eep.Article(t[1]), eep.Article(t[2])] 

    //              for t in n3tolist(s)]

  }





  /** 

   * This parses a N3 string and returns a memmodel 

   * @param string $s

   * @access public 

   * @return object Model

   **/



  function parse2model($s,$model = false) {

	if($model == false){

	    $m=new MemModel();

	}else{

		$m=$model;

	}

    //   """Get a string, tokenize, create list, convert to Eep store."""

    $stat=$this->n3tolist($s);



    foreach ( $stat as $t) { 

      $s=$this->toRDFNode($t[0],$t);

      $p=$this->toRDFNode($t[1],$t);

      $o=$this->toRDFNode($t[2],$t);

      	

       $new_statement= new Statement($s,$p,$o);     



      $m->add($new_statement);

      //    print "(".$t[0].", ".$t[1].", ".$t[2].")";

    }

    //   return [[eep.Article(t[0]), eep.Article(t[1]), eep.Article(t[2])] 

    //              for t in n3tolist(s)]

    $m->addParsedNamespaces($this->parsedNamespaces);

    return $m;

  }



/**

 * Generate a new MemModel from an URI or file.

 *

 * @access	public

 * @param $path

 * @throws PhpError

 * @return object MemModel

 */

  function & generateModel($path,$dummy=false,$model=false) {



    $handle = fopen($path,'r') or die("N3 Parser: Could not open File: '$path' - Stopped parsing.");

	$done=false;

	$input="";

	while(!$done)

	{

	  $input .= fread( $handle, 512 );

	  $done = feof($handle);

	  

	}; 



  

    fclose($handle);



    return $this->parse2model($input,$model);

  }

  

  

  /* ==================== Private Methods from here ==================== */



  //  General list processing functions



/**

 * Returns FALSE if argument is a whitespace character

 * @access private

 * @param string $s

 **/

  function isWS($s) { 

    return !preg_match('/^(#.*|\s*)$/', $s);

  }







  /** 

   * Returns true if the string is not a comment

   * @access private

   * @param string $s

   * @returns boolean

   **/

  function notComment($s) {

    if ($s=="") return false; 

    $N3Comment = '^[ \t]*\#';

  

    if (ereg($N3Comment,$s)) return false;

    else return true;

  }



  /**

   * Removes all whitespace tokens from list

   * @access private 

   * @param array $list

   **/

  function filterWs($list) {

    //    var_dump($list);

    //  """Filter whitespace from a list."""



    return array_filter($list, array($this,"isWS"));

  }

  

/**

* converts a string to its unicode NFC form (e.g. \uHHHH or \UHHHHHHHH).

* 

* @param String $str

* @return String 

* @access private

*

*/

function str2unicode_nfc($str=""){

	$result="";

	/* try to detect encoding */

	$tmp=str_replace("?", "", $str);

	if(strpos(utf8_decode($tmp), "?")===false){

		$str=utf8_decode($str);

	}

	for($i=0,$i_max=strlen($str);$i<$i_max;$i++){

		$nr=0;/* unicode dec nr */

		/* char */

		$char=$str[$i];

		/* utf8 binary */

		$utf8_char=utf8_encode($char);

		$bytes=strlen($utf8_char);

		if($bytes==1){

			/* 0####### (0-127) */

			$nr=ord($utf8_char);

		}

		elseif($bytes==2){

			/* 110##### 10###### = 192+x 128+x */

			$nr=((ord($utf8_char[0])-192)*64) + (ord($utf8_char[1])-128);

		}

		elseif($bytes==3){

			/* 1110#### 10###### 10###### = 224+x 128+x 128+x */

			$nr=((ord($utf8_char[0])-224)*4096) + ((ord($utf8_char[1])-128)*64) + (ord($utf8_char[2])-128);

		}

		elseif($bytes==4){

			/* 1111#### 10###### 10###### 10###### = 240+x 128+x 128+x 128+x */

			$nr=((ord($utf8_char[0])-240)*262144) + ((ord($utf8_char[1])-128)*4096) + ((ord($utf8_char[2])-128)*64) + (ord($utf8_char[3])-128);

		}

		/* result (see http://www.w3.org/TR/rdf-testcases/#ntrip_strings) */

		if($nr<9){/* #x0-#x8 (0-8) */

			$result.="\\u".sprintf("%04X",$nr);

		}

		elseif($nr==9){/* #x9 (9) */

			$result.='\t';

		}

		elseif($nr==10){/* #xA (10) */

			$result.='\n';

		}

		elseif($nr<13){/* #xB-#xC (11-12) */

			$result.="\\u".sprintf("%04X",$nr);

		}

		elseif($nr==13){/* #xD (13) */

			$result.='\t';

		}

		elseif($nr<32){/* #xE-#x1F (14-31) */

			$result.="\\u".sprintf("%04X",$nr);

		}

		elseif($nr<34){/* #x20-#x21 (32-33) */

			$result.=$char;

		}

		elseif($nr==34){/* #x22 (34) */

			$result.='\"';

		}

		elseif($nr<92){/* #x23-#x5B (35-91) */

			$result.=$char;

		}

		elseif($nr==92){/* #x5C (92) */

			$result.='\\';

		}

		elseif($nr<127){/* #x5D-#x7E (93-126) */

			$result.=$char;

		}

		elseif($nr<65536){/* #x7F-#xFFFF (128-65535) */

			$result.="\\u".sprintf("%04X",$nr);

		}

		elseif($nr<1114112){/* #x10000-#x10FFFF (65536-1114111) */

			$result.="\\U".sprintf("%08X",$nr);

		}

		else{

			/* other chars are not defined => ignore */

		}

	}

	return $result;

}



  



  /**

   * Gets a slice of an array. 

   * Returns the wanted slice, as well as the remainder of the array.

   * e.g. getSpan(['p', 'q', 'r'], 1, 2) gives (['q'], ['p', 'r'])

   * @return array

   * @access private

   * @param array $list

   * @param integer $start

   * @param integer $end

   **/

  function getSpan($list, $start, $end) {

    

    $pre=array_slice($list, 0, $start);

    $post=array_slice($list, $end);



    return array(array_slice($list, $start,$end-$start),$this->array_concat($pre,$post));

  }





  /** 

   * Concatenates two arrays 

   * @param array $a

   * @param array $b

   * @returns array

   * @access private

   **/

  function array_concat($a, $b) { 

    array_splice($a,count($a),0,$b);

    return $a;

  }



  /**

   * Returns an array with all indexes where item appears in list

   * @param array $list 

   * @param string $item

   * @returns array

   * @access private 

   **/

  function posns($list, $item) { 

    $res=array(); 

    $i=0;

    foreach ( $list as $k=>$v) {     

      if ($v === $item ) $res[]=$i;

      $i++;

    }

    $res[]=$i;

    return $res;

  }





  /* More N3 specific functions */



  /** 

   * Returns a list of tokens

   * @param string $s

   * @returns array

   * @access private

   **/

  function toke($s) {



    //    print "$s\n";

    //   """Notation3 tokenizer. Takes in a string, returns a raw token list."""

    if (strlen($s) == 0) die('Document has no content!');



    $s=str_replace("\r\n","\n",$s);

    $s=str_replace("\r","\n",$s);





    //$lines=explode("\n",$s);



    //$reallines=array_filter($lines, array($this, "notComment"));

    //    print "LINES: ".join($reallines, " ")." :LINES\n";

    //array_walk($reallines, array($this, "trimLine"));

    //$res=array();



    //    foreach ($reallines as $l) {    

    //preg_match_all($this->Tokens, $l, $newres);

    //$res=$this->array_concat($res,$newres[0]);

    //}



    $res=array();

    preg_match_all($this->Tokens, $s, $newres);



    $res=$this->array_concat($res, array_map('trim', $newres[0]));

  

    return $res;

  }

 

  /** 

   * Returns a list with the elements between start and end as one quoted string

   * e.g. listify(["a","b","c","d"],1,2) => ["a","b c", "d"]

   * @param array $list

   * @param integer $start

   * @param integer $end

   * @returns array

   * @access private

   **/

  function listify($list, $start, $end) {



    //Re-form a list, merge elements start->end into one quoted element

    //Start and end are offsets...



    $l=$end-$start;



    $s=array_slice($list, 0, $start);

    $m=array_slice($list, $start,$l);

    $e=array_slice($list, $end);

  

    //  array_push($s,"\"".join($m," ")."\"");

    array_push($s,$m);

  

    return $this->array_concat($s,$e);

  }



  /**

   * Returns an array with prefixes=>namespace mappings

   * @param array $list 

   * @access private 

   * @returns array

   **/

  function getPrefixes($list) {



    $prefixes=array();

    $ns=1;

    $name=2;

    foreach ($list as $l) { 

      if ($l=='@prefix') { 

	//   while '@prefix' in list {

      

	$pos=current($list);

	//pos = list.index('@prefix')

	$r = $this->getSpan($list, $pos, ($pos+4)); # processes the prefix tokens

	$binding=$r[0];

	$list=$r[1];

	$prefixes[$binding[$ns]] = substr($binding[$name],1,-1);

	$this->parsedNamespaces[substr($binding[$name],1,-1)] = substr($binding[$ns],0,-1);

      }

    }

 

	if (count($prefixes)<1) $list= array_slice($list,0);

	

    return array($prefixes, $list);

  }



  /**

   * Callback function for replacing "a" elements with the right RDF uri.

   * @param string $l

   * @access private

   **/

  function replace_a_type(&$l,$p) {

    if ($l=='a') $l='<'.$this->RDF_NS.'type>';

  }



  /**

   * Callback function for replacing "=" elements with the right DAML+OIL uri.

   * @param string $l

   * @access private

   **/

  function replace_equal(&$l,$p) {

    if ($l=='=') $l='<'.$this->OWL_NS.'sameAs>';

  }



  /**

   * Callback function for replacing "this" elements with the right RDF uri.

   * @param string $l

   * @access private

   **/

  function replace_this($l,$p) {

    if ($l=='this') $l='<urn:urn-n:this>';

  }



  /**

   * Applies stuff :) 

   * Expands namespace prefixes etc. 

   * @param array $prefixes

   * @param array $list

   * @returns $list

   * @access private

   **/

  function applyStuff($prefixes, $list) {



    array_walk($list, array($this, 'replace_a_type'));

    array_walk($list, array($this, 'replace_equal'));

    array_walk($list, array($this, 'replace_this'));



    for ($i=0;$i<count($list);$i++) { 

      //   for i in range(len(list)) {

//      if (!strstr('<_"?.;,{}[]()',$list[$i]{0})) {





// if a <> resource occours, change it to the parsed filename or local URI + timestamp



	    if ($list[$i]=='<>') {

    		if (!isset($path)) { 

				if (!isset($_SERVER['SERVER_ADDR'])) $_SERVER['SERVER_ADDR']='localhost';

				if (!isset($_SERVER['REQUEST_URI'])) $_SERVER['REQUEST_URI']='/rdfapi-php';

    			$list[$i]='<http://'.$_SERVER['SERVER_ADDR'].$_SERVER['REQUEST_URI'].'#generate_timestamp_'.time().'>';

    			

    	  }else {$list[$i]='<'.$path.'>';};

    	};		





		if ((!strstr('<_"?.;,{}[]()@',$list[$i]{0}))AND (substr($list[$i],0,3)!='^^<')) {

	  $_r= explode(":",$list[$i]);











	$ns=$_r[0].':';

	$name=$_r[1];

  

	if (isset($prefixes[$ns])) $list[$i] = '<'.$prefixes[$ns].$name.'>';

	else if (isset($prefixes[substr($ns,2)])) $list[$i] = '^^'.$prefixes[substr($ns,2)].$name.''; 

  else {

  #die('Prefix not declared:'.$ns);

  	$this->parseError=true;

	trigger_error('Prefix not declared: '.$ns, E_USER_ERROR);

	break;

	

	

  }

  

      } else {       

	if ($list[$i]{0} == '"') {  // Congratulations - it's a literal!

	  if (substr($list[$i],0,3) == '"""') {

	    if (substr($list[$i],-3,3) == '"""') { // A big literal...

	      $lit = substr($list[$i],3,-3);	     

	      //	      print "++$lit++";

	      $lit=str_replace('\n', '\\n',$lit);



	      $lit=ereg_replace("[^\\]\"", "\\\"", $lit);



	      $list[$i] = '"'.$lit.'"';

	    }

	    else { die ('Incorrect string formatting: '.substr($list[$i],-3,3)); }

	  } else {

	    if (strstr($list[$i],"\n")) die('Newline in literal: '+$list[$i]);

	  }

	}

      }

    

      if (substr($list[$i],0,2)=='^^') {

        if ($list[$i][2]!='<'){$list[$i]='^^<'.substr($list[$i],2).'>';};

      };



    

    }





    return $list;

  }



  /** 

   * Returns an array of triples extracted from the list of n3 tokens

   * @param array $list

   * @returns array 

   * @access private

   **/

  function getStatements($list) {





    $statements = array();



    while (in_array('.', $list)) {

      //  for($i=0;$i<count($list); $i++) {

      //    if ($list[$i]==".") {

      //   while '.' in list {

      $pos=array_search('.',$list);



      $r=$this->getSpan($list, 0, $pos+1);    



      $statement=$r[0];

      $list = $r[1];



      array_pop($statement);

      $statements[]=$statement;

    }



    return $statements;

  }

  

  /** 

   * Gets a list of triples with same subject

   * e.g. :Gunnar :firstname "Gunnar" ; :lastname "Grimnes.

   * @param array $list

   * @returns array

   * @acces private

   **/

  function getPovs($list) {

    $povs = array();

    while (in_array(';', $list)) {

      $r=$this->posns($list,';');

      $pos=array_slice($r,0,2);

      $r = $this->getSpan($list, $pos[0], $pos[1]);

      $pov=$r[0];

      $list=$r[1];



      // skip lone semicolons, e.g. "<a> <b> <c> ; ."

      if (count($pov) == 1) continue;



      $povs[]=array_slice($pov,1);

    }



    return array($list, $povs);

  }



  /** 

   * Gets a list of triples with same predicate

   * e.g. :Gunnar :likes "Cheese", "Wine". 

   * @access private

   * @param array $list

   * @returns array

   **/

  function getObjs($list) {





    $objs = array();

    while (in_array(",",$list)) {

      $pos=array_search(",",$list);

      //  for($i=0;$i<count($list); $i++) {

      //    if ($list[$i]==",") {

      //   while ',' in list {





      $get_array_fields=2;

      if (isset ($list[$pos+2])) { 

      	if (@$list[$pos+2][0]=='@') $get_array_fields++;

        if (@$list[$pos+2][0]=='^') $get_array_fields++;

      };

      if (isset ($list[$pos+3])) { if (@$list[$pos+3][0]=='^') $get_array_fields++;};





      $r=$this->getSpan($list, $pos, ($pos+$get_array_fields));



      $obj=$r[0];

      if (!isset($obj[2])) $obj[2]=' ';

      if (!isset($obj[3])) $obj[3]=' ';

      

      $list=$r[1];



     

      $objs[]=$obj;

 



    }

  

    return array($list, $objs);

  }



  /**

   * Does the real work, returns a list of subject, predicate, object triples. 

   * @param array $list

   * @returns array

   * @access private

   **/

  function statementize($list) {



    if (count($list) == 1 && preg_match("/_".BNODE_PREFIX."[0-9]+_/",$list[0])) { 

	if ($this->debug) print "Ignored bNode exists statement. $list\n";

	return array(); 

    }



    

    

    if (count($list) == 3) return array($list);

    if (count($list) < 3) die("Error: statement too short!");



    //Get all ; 

    $r=$this->getPovs($list);

    $spo=$r[0];

    $po=$r[1];

    $all=array();







    //      (spo, po), all = getPovs(list), []

    $subject = $spo[0];

    foreach ($po as $pop) {

      //  for pop in po {

      $r=$this->getObjs($pop);



      $myPo=$r[0];

      $obj=$r[1];

      //myPo, obj = getObjs(pop)



      if (!isset($myPo[2])) $myPo[2]=' ';

      if (!isset($myPo[3])) $myPo[3]=' ';

 

    

      $predicate = $myPo[0];

      $all[]=array($subject,$predicate,$myPo[1],$myPo[2],$myPo[3]);

      //    all.append([subject, predicate, myPo[1]])



       



      foreach ($obj as $o) $all[]=array($subject,$predicate, $o[1],$o[2],$o[3]);

      //         for x in obj: all.append([subject, predicate, x])



    }







    $r = $this->getObjs($spo);

    $spo=$r[0];



    $objs=$r[1];



    //spo, objs = getObjs(spo)

    $subject=$spo[0];

    $predicate=$spo[1];



    

    if(!isset($spo[3])) $spo[3]=' ';     

    if(!isset($spo[4])) $spo[4]=' ';     

      

    $all[]=array($subject, $predicate, $spo[2],$spo[3],$spo[4]);



    foreach ($objs as $obj) $all[]=array($subject, $predicate, $obj[1],$obj[2],$obj[3]);



    return $all;

  }



  /**

   * Makes lists of elements in list into a seperate array element.

   * e.g. doLists(["a","b","[","c","]","d"], "[","]")=> ["a","b", ["c"], "d"]

   * @param array $list

   * @param string $schar

   * @param string $echar

   * @returns array

   * @access private 

   **/

  function doLists($list, $schar, $echar) {



    while (in_array($schar, $list)) {

      //   while schar in list {

      $ndict=array();

      $nestingLevel=0;

      $biggest=0;

      for ($i=0;$i<count($list);$i++) {

	if ($list[$i] == $schar) {

	  $nestingLevel += 1;

	  if (!in_array($nestingLevel, array_keys($ndict))) {

	    $ndict[$nestingLevel] = array(array($i));

	  } else { 

	    $ndict[$nestingLevel][]=array($i);

	  }

	}

	if ($list[$i] == $echar) {

	  if (!in_array($nestingLevel, array_keys($ndict))) {

	    $ndict[$nestingLevel]=array(array($i));

	  } else { 

            $ndict[$nestingLevel][count($ndict[$nestingLevel])-1][]=$i;

            $nestingLevel-= 1;

# elif type(list[i]) == type([]) {

#    list[i] = doLists(list[i], schar, echar)

	  }

	}

      }

      foreach (array_keys($ndict) as $key) 

	if ($key > $biggest)  $biggest = $key;



      $tol = $ndict[$biggest][0];

      $list = $this->listify($list, $tol[0], ($tol[1]+1));

    }

    return $list;

  }



  /** 

   * Apply doLists for all different types of list. 

   * @param array

   * @returns array

   * @access private

   **/

  function listStuff($list) {

# y, z = zip(['[', ']'], ['{', '}'], ['(', ')'])

# return map(doLists, [list, list, list], y, z).pop()

    $list = $this->doLists($list, '[', ']');

    $list = $this->doLists($list, '{', '}');

    return $this->doLists($list, '(', ')');

  }



  /**

   * Generates a new node id. 

   * @access private

   * @returns string

   **/

  function bnodeID() {

  

    $this->bNode++;

    return "_".BNODE_PREFIX.$this->bNode."_";

  }



  /** 

   * This makes bNodes out of variables like _:a etc.

   * @access private

   * @param array $list

   * @returns array

   **/

  function fixAnon($list) {

//    $map=array();

    for($i=0;$i<count($list);$i++) {

      $l=$list[$i];

      if (substr($l,0,2)=="_:") {

	  if (!isset($this->bNodeMap[$l])) {

	  $a=$this->bnodeID();

	  $this->bNodeMap[$l]=$a;

	} else $a=$this->bNodeMap[$l];

	$list[$i]=$a;

      }

    }

    return $list;

  }



  /**

   * This makes [ ] lists into bnodes. 

   * @access private

   * @param array $list

   * @return array 

   **/

  function expandLists($list) {



    for($i=0;$i<count($list);$i++) {

      if (is_array($list[$i])) {

	if ( $list[$i][0]=='[' ) {

	  $bnode=$this->bnodeID();

	  $prop=$list[$i];

	  $list[$i]=$bnode;

	  $list[]=$bnode;

	  $list=$this->array_concat($list, array_slice($prop,1,-1));

	  $list[]='.';

	}elseif($list[$i][0]=='(') {



	    $rdfNil = '<'. RDF_NAMESPACE_URI . RDF_NIL .'>';

	    $rdfFirst = '<'. RDF_NAMESPACE_URI . RDF_FIRST .'>';

	    $rdfRest = '<'. RDF_NAMESPACE_URI . RDF_REST .'>';



	    // local copy of list without "(" and ")"

	    $t_list = array_slice($list[$i], 1, -1);



	    //prepare bnodes

	    $fromBnode = $this->bnodeID();

	    $toBnode = $this->bnodeID();



	    //link first bnode into graph

	    $list[$i] = $fromBnode;



	    $count = count($t_list);



	    //loop through list, convert to RDF linked list

	    for ($idx = 0; $idx < $count; $idx++){



	        // set rdf:first

	        $list[] = $fromBnode;

	        $list[] = $rdfFirst;

	        $list[] = $t_list[$idx];

	        $list[] = '.';



	        // set rdf:rest (nil or next bnode)

	        if ($idx == $count - 1) {

	            $list[] = $fromBnode;

	            $list[] = $rdfRest;

	            $list[] = $rdfNil;

	            $list[] = '.';

	        }

	        else {

	            $list[] = $fromBnode;

	            $list[] = $rdfRest;

	            $list[] = $toBnode;

	            $list[] = '.';



	            $fromBnode = $toBnode;

	            $toBnode = $this->bnodeID();

	        }

	    }

	}

	else {

	    die('Only [ ] and () lists are supported!');

	}

    }



    

    }

    return $list;

  }



  /** 

   * Main work-horse function. This converts a N3 string to a list of statements 

   * @param string $s

   * @returns array

   * @access private 

   **/

  function n3tolist($s) {



    //   """Convert an N3 string into a list of triples as strings."""

    $result = array();



   $t = $this->filterWs($this->toke($s)); # tokenize the stream, and filter whitespace tokens



    if ($this->debug) {

      print "Filter WS:\n";

      var_dump($t);

    }

    $r=$this->getPrefixes($t); # get the prefix directives, and add to a dict

    $prefixes=$r[0];

    $t=$r[1];

    if ($this->debug) {

      print "Prefixes:\n";

      var_dump($prefixes);

      print "***\n";

      var_dump($t);

    }

    $t=$this->applyStuff($prefixes, $t);#apply prefixes, keywords, and string formatting 

    if ($this->debug) {

      print "Stuff applied:\n";

      var_dump($t);

    }



    $t=$this->fixAnon($t); # fix _:a anons

    if ($this->debug) {

      print "Fix anon:\n";

      var_dump($t);

    }

    

    $t = $this->listStuff($t); # apply list stuff: todo

    if ($this->debug) {

      print "Lists done:\n";

      var_dump($t);

    }

    $t=$this->expandLists($t);

    if ($this->debug) {

      print "Lists applied:\n";

      var_dump($t);

    }

    $t = $this->getStatements($t); # get all of the "statements" from the stream



    foreach ($t as $stat) {

      $stats=$this->statementize($stat);

 

      foreach ($stats as $y) {

	$result[]=$y;

      }

    }

    //   for x in [statementize(stat) for stat in t] {

    //      for y in x: result.append(y)

    return $result;

  }



  /** 

   * Constructs a RAP RDFNode from URI/Literal/Bnode

   * @access private

   * @param string $s

   * @returns object RDFNode

   **/

  function toRDFNode($s,$state) {

	$ins=substr($s,1,-1);

    if ($s{0}=="\"") {

      $lang=NULL;

	





      if (count($state)>3) {           





        for ($i = 3; $i < count($state); $i++){

          if ($state[$i][0]=='@')$lang=substr($state[3],1);

          if (substr($state[$i],0,2)=='^^'){

            

            $dtype=substr($state[$i],2);

            if ($dtype[0]=='<') $dtype= substr($dtype,1,-1);

            

          };

          

        };

      };

      

    

     if(UNIC_RDF){

      	$ins=$this->str2unicode_nfc($ins);

      }

      $new_Literal=new Literal($ins,$lang);

      if (isset($dtype)) $new_Literal->setDatatype($dtype);     

      return  $new_Literal;        

    };



	if (strstr($s,'_'.BNODE_PREFIX)) { 

		if (($this->FixBnodes) OR (!array_search($s,$this->bNodeMap))) {

			return new BlankNode($ins);

		} else {return new BlankNode(trim(substr(array_search($s,$this->bNodeMap),2)));

		};

	}

    

    return new Resource($ins); 

  }





  

  

} //end: N3Parser



?>