Eng/Rus/Ukr Stemmer by Andrew Kovalenko

<?php
    /******************************************************************************
    * Copyright (c) 1994-2002
    * Andrew Kovalenko aka Keva.  All rights reserved.
    *      http://www.keva.ru/
    *
    * 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. Redistributions in any form must be accompanied by information on
    *    how to obtain complete source code for the stemming software and any
    *    accompanying software that uses the stemming software.  The source code
    *    must either be included in the distribution or be available for no
    *    more than the cost of distribution plus a nominal fee, and must be
    *    freely redistributable under reasonable conditions.  For an
    *    executable file, complete source code means the source code for all
    *    modules it contains.  It does not include source code for modules or
    *    files that typically accompany the major components of the operating
    *    system on which the executable file runs.
    *
    * THIS SOFTWARE IS PROVIDED BY ANDREW KOVALENKO ``AS IS'' AND ANY EXPRESS
    * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
    * NON-INFRINGEMENT, ARE DISCLAIMED.  IN NO EVENT SHALL ANDREW KOVALENKO
    * 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.
    *****************************************************************************/
    /******************************************************************************
    * Porting on PHP by Sedlyar Alexandr aka Seth 27.08.2009 All rights reserved.
    * http://seteh.in.ua
    *****************************************************************************/
    class stemka {
        var $vowels = "аеиоуыэюя";
        var $fuzzyLang = '';
        function GetStem($word, $lang = '', $path = '') {
            $this->minstem = $this->GetMinStem($word);
            $this->mcount = 5;
            $this->lplist = null;
            $fflag = true;
            if ($this->fuzzyLang != $lang)
                $fflag = $this->LoadFuzzy($lang, $path);
            if ($fflag) {
                $lcount = $this->GetStemLen($word, 0, strlen($word)-1);
                $result = '';
                if (is_array($this->lplist)) {
                    foreach (array_reverse($this->lplist) as $v) {
                        $result = '|' . substr($word, $v, strlen($word) - $v) . $result;
                        $word = substr($word, 0, $v);
                    }
                }
                $result = $word . $result;
            } else {
                $result = $word;
            }
            return $result;
        }
        function GetStemCrop($word, $lang = '', $path = '') {
            $this->minstem = $this->GetMinStem($word);
            $this->mcount = 5;
            $this->lplist = null;
            $fflag = true;
            if ($this->fuzzyLang != $lang)
                $fflag = $this->LoadFuzzy($lang, $path);
            if ($fflag) {
                $lcount = $this->GetStemLen($word, 0, strlen($word)-1);
                if ($lcount > 0)
                    $res = substr($word, 0, $this->lplist[0]);
                else
                    $res = $word;
                return $res;
            } else {
                return $word;
            }
        }
        function GetMinStem($word) {
            $length = strlen($word);
            for ($nindex = 0; $nindex < $length; $nindex++ ) {
                if (strchr($this->vowels, $word[$nindex] ) !== FALSE ) {
                    while (++$nindex < $length && strchr($this->vowels, $word[$nindex] ) !== FALSE) {
                    }
                    return $nindex + 1;
                }
            }
            return $length;
        }
        function GetStemLen($word, $offset, $lptail) {
            $lpbase = $offset;
            $cchars = ord($this->fuzzy[$lpbase]);
            $pchars = $lpbase + $cchars;
            $lpoffs = ($pchars - 1) + $cchars * 2;
            $ptable = $word;
            $stmlen = $lptail + 1;
            $result = 0;
            while ($pchars > $lpbase) {
                while ($pchars > $lpbase && ord($this->fuzzy[$pchars]) != 0 && $this->fuzzy[$pchars] != $ptable[$lptail] ) {
                    $pchars--;
                    $lpoffs -= 2;
                }
                if ($pchars <= $lpbase)
                    continue;
                if ($this->fuzzy[$pchars] == $ptable[$lptail] && $stmlen > $this->minstem - 2) {
                    $lpoffs_tmp = (ord($this->fuzzy[$lpoffs+1]) << 8) + ord($this->fuzzy[$lpoffs]);
                    $result += $this->GetStemLen($word, $lpoffs_tmp << 3, $lptail - 1 );
                } elseif (ord($this->fuzzy[$pchars]) == 0 && $stmlen >= $this->minstem - 2 && $this->mcount != 0 ) {
                    $this->lplist[] = $stmlen + 2;
                    $this->mcount--;
                    return $result + 1;
                }
                $pchars--;
                $lpoffs -= 2;
            }
            return $result;
        }
        function LoadFuzzy($lang = '', $path = '') {
            if (file_exists($path . 'fuzzy' . $lang . '.dat')) {
                $this->fuzzy = file_get_contents($path . 'fuzzy' . $lang . '.dat');
                $ret = true;
            } else {
                $this->fuzzy = '';
                $ret = false;
            }
            return $ret;
        }
    }
?>