<?php
if (!defined("ENGLISHSTEMMER"))
{
define("ENGLISHSTEMMER",1,false);
class EnglishStemmer
{
var $regex_consonant = '(?:[bcdfghjklmnpqrstvwxz]|(?<=[aeiou])y|^y)';
var $regex_vowel = '(?:[aeiou]|(?<![aeiou])y)';
function Stem($word)
{
if (strlen($word) <= 2) {
return $word;
}
$word = $this->step1ab($word);
$word = $this->step1c($word);
$word = $this->step2($word);
$word = $this->step3($word);
$word = $this->step4($word);
$word = $this->step5($word);
/*
Esta parte esta editado por cesar rodas,
no quiero que me muestre ' (apostrofe) al final
*/
if (substr($word,-1,1) == "'")
$word = substr($word,0,strlen($word) -1 );
return $word;
}
function step1ab($word)
{
if (substr($word, -1) == 's') {
$this->replace($word, 'sses', 'ss')
OR $this->replace($word, 'ies', 'i')
OR $this->replace($word, 'ss', 'ss')
OR $this->replace($word, 's', '');
}
if (substr($word, -2, 1) != 'e' OR !$this->replace($word, 'eed', 'ee', 0)) { // First rule
$v = $this->regex_vowel;
if ( preg_match("#$v+#", substr($word, 0, -3)) && $this->replace($word, 'ing', '')
OR preg_match("#$v+#", substr($word, 0, -2)) && $this->replace($word, 'ed', '')) {
if ( !$this->replace($word, 'at', 'ate')
AND !$this->replace($word, 'bl', 'ble')
AND !$this->replace($word, 'iz', 'ize')) {
if ( $this->doubleConsonant($word)
AND substr($word, -2) != 'll'
AND substr($word, -2) != 'ss'
AND substr($word, -2) != 'zz') {
$word = substr($word, 0, -1);
} else if ($this->m($word) == 1 AND $this->cvc($word)) {
$word .= 'e';
}
}
}
}
return $word;
}
function step1c($word)
{
$v = $this->regex_vowel;
if (substr($word, -1) == 'y' && preg_match("#$v+#", substr($word, 0, -1))) {
$this->replace($word, 'y', 'i');
}
return $word;
}
function step2($word)
{
switch (substr($word, -2, 1)) {
case 'a':
$this->replace($word, 'ational', 'ate', 0)
OR $this->replace($word, 'tional', 'tion', 0);
break;
case 'c':
$this->replace($word, 'enci', 'ence', 0)
OR $this->replace($word, 'anci', 'ance', 0);
break;
case 'e':
$this->replace($word, 'izer', 'ize', 0);
break;
case 'g':
$this->replace($word, 'logi', 'log', 0);
break;
case 'l':
$this->replace($word, 'entli', 'ent', 0)
OR $this->replace($word, 'ousli', 'ous', 0)
OR $this->replace($word, 'alli', 'al', 0)
OR $this->replace($word, 'bli', 'ble', 0)
OR $this->replace($word, 'eli', 'e', 0);
break;
case 'o':
$this->replace($word, 'ization', 'ize', 0)
OR $this->replace($word, 'ation', 'ate', 0)
OR $this->replace($word, 'ator', 'ate', 0);
break;
case 's':
$this->replace($word, 'iveness', 'ive', 0)
OR $this->replace($word, 'fulness', 'ful', 0)
OR $this->replace($word, 'ousness', 'ous', 0)
OR $this->replace($word, 'alism', 'al', 0);
break;
case 't':
$this->replace($word, 'biliti', 'ble', 0)
OR $this->replace($word, 'aliti', 'al', 0)
OR $this->replace($word, 'iviti', 'ive', 0);
break;
}
return $word;
}
function step3($word)
{
switch (substr($word, -2, 1)) {
case 'a':
$this->replace($word, 'ical', 'ic', 0);
break;
case 's':
$this->replace($word, 'ness', '', 0);
break;
case 't':
$this->replace($word, 'icate', 'ic', 0)
OR $this->replace($word, 'iciti', 'ic', 0);
break;
case 'u':
$this->replace($word, 'ful', '', 0);
break;
case 'v':
$this->replace($word, 'ative', '', 0);
break;
case 'z':
$this->replace($word, 'alize', 'al', 0);
break;
}
return $word;
}
function step4($word)
{
switch (substr($word, -2, 1)) {
case 'a':
$this->replace($word, 'al', '', 1);
break;
case 'c':
$this->replace($word, 'ance', '', 1)
OR $this->replace($word, 'ence', '', 1);
break;
case 'e':
$this->replace($word, 'er', '', 1);
break;
case 'i':
$this->replace($word, 'ic', '', 1);
break;
case 'l':
$this->replace($word, 'able', '', 1)
OR $this->replace($word, 'ible', '', 1);
break;
case 'n':
$this->replace($word, 'ant', '', 1)
OR $this->replace($word, 'ement', '', 1)
OR $this->replace($word, 'ment', '', 1)
OR $this->replace($word, 'ent', '', 1);
break;
case 'o':
if (substr($word, -4) == 'tion' OR substr($word, -4) == 'sion') {
$this->replace($word, 'ion', '', 1);
} else {
$this->replace($word, 'ou', '', 1);
}
break;
case 's':
$this->replace($word, 'ism', '', 1);
break;
case 't':
$this->replace($word, 'ate', '', 1)
OR $this->replace($word, 'iti', '', 1);
break;
case 'u':
$this->replace($word, 'ous', '', 1);
break;
case 'v':
$this->replace($word, 'ive', '', 1);
break;
case 'z':
$this->replace($word, 'ize', '', 1);
break;
}
return $word;
}
function step5($word)
{
if (substr($word, -1) == 'e') {
if ($this->m(substr($word, 0, -1)) > 1) {
$this->replace($word, 'e', '');
} else if ($this->m(substr($word, 0, -1)) == 1) {
if (!$this->cvc(substr($word, 0, -1))) {
$this->replace($word, 'e', '');
}
}
}
// Part b
if ($this->m($word) > 1 AND $this->doubleConsonant($word) AND substr($word, -1) == 'l') {
$word = substr($word, 0, -1);
}
return $word;
}
function replace(&$str, $check, $repl, $m = null)
{
$len = 0 - strlen($check);
if (substr($str, $len) == $check) {
$substr = substr($str, 0, $len);
if (is_null($m) OR $this->m($substr) > $m) {
$str = $substr . $repl;
}
return true;
}
return false;
}
function m($str)
{
$c = $this->regex_consonant;
$v = $this->regex_vowel;
$str = preg_replace("#^$c+#", '', $str);
$str = preg_replace("#$v+$#", '', $str);
preg_match_all("#($v+$c+)#", $str, $matches);
return count($matches[1]);
}
function doubleConsonant($str)
{
$c = $this->regex_consonant;
return preg_match("#$c{2}$#", $str, $matches) AND $matches[0]{0} == $matches[0]{1};
}
function cvc($str)
{
$c = $this->regex_consonant;
$v = $this->regex_vowel;
return preg_match("#($c$v$c)$#", $str, $matches)
AND strlen($matches[1]) == 3
AND $matches[1]{2} != 'w'
AND $matches[1]{2} != 'x'
AND $matches[1]{2} != 'y';
}
}
}
?>