/**
* Remove stop words.
*
* @param string $text The text which stop words to be removed
* @return string The text after removal
*/
public function remove($text)
{
$words = explode(' ', $text);
foreach ($words as $i => $word) {
if ($this->dictionary->contains($word)) {
unset($words[$i]);
}
}
return implode(' ', $words);
}
/**
* ECS Loop Pengembalian Akhiran
*/
public function loopPengembalianAkhiran()
{
// restore prefix to form [DP+[DP+[DP]]] + Root word
$this->restorePrefix();
$removals = $this->removals;
$reversedRemovals = array_reverse($removals);
$currentWord = $this->getCurrentWord();
foreach ($reversedRemovals as $removal) {
if (!$this->isSuffixRemoval($removal)) {
continue;
}
if ($removal->getRemovedPart() == 'kan') {
$this->setCurrentWord($removal->getResult() . 'k');
// step 4, 5
$this->removePrefixes();
if ($this->dictionary->contains($this->getCurrentWord())) {
return;
}
$this->setCurrentWord($removal->getResult() . 'kan');
} else {
$this->setCurrentWord($removal->getSubject());
}
// step 4, 5
$this->removePrefixes();
if ($this->dictionary->contains($this->getCurrentWord())) {
return;
}
$this->removals = $removals;
$this->setCurrentWord($currentWord);
}
}
/**
* Stem a plural word to its common stem form.
* Asian J. (2007) “Effective Techniques for Indonesian Text Retrieval” page 76-77.
*
* @param string $plural the word to stem, e.g : bersama-sama
* @return string common stem form, e.g : sama
* @link http://researchbank.rmit.edu.au/eserv/rmit:6312/Asian.pdf
*/
protected function stemPluralWord($plural)
{
preg_match('/^(.*)-(.*)$/', $plural, $words);
if (!isset($words[1]) || !isset($words[2])) {
return $plural;
}
// malaikat-malaikat-nya -> malaikat malaikat-nya
$suffix = $words[2];
if (in_array($suffix, array('ku', 'mu', 'nya', 'lah', 'kah', 'tah', 'pun')) && preg_match('/^(.*)-(.*)$/', $words[1], $words)) {
$words[2] .= '-' . $suffix;
}
// berbalas-balasan -> balas
$rootWord1 = $this->stemSingularWord($words[1]);
$rootWord2 = $this->stemSingularWord($words[2]);
// meniru-nirukan -> tiru
if (!$this->dictionary->contains($words[2]) && $rootWord2 === $words[2]) {
$rootWord2 = $this->stemSingularWord('me' . $words[2]);
}
if ($rootWord1 == $rootWord2) {
return $rootWord1;
} else {
return $plural;
}
}
