<?php
/**
* SeekQuarry/Yioop --
* Open Source Pure PHP Search Engine, Crawler, and Indexer
*
* Copyright (C) 2009 - 2026 Chris Pollett chris@pollett.org
*
* LICENSE:
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
* @author Niravkumar Patel niravkumar.patel1989@gmail.com
* @license https://www.gnu.org/licenses/ GPL3
* @link https://www.seekquarry.com/
* @copyright 2009 - 2026
* @filesource
*/
namespace seekquarry\yioop\locale\pt\resources;
/**
* This class has a collection of methods for Portuguese locale specific
* tokenization. In particular, it has a stemmer implementing the
* Snowball Stemming algorithm presented in
* http://snowball.tartarus.org/algorithms/portuguese/stemmer.html
*
* @author Niravkumar Patel
*/
class Tokenizer
{
/**
* A list of frequently occurring terms for this locale which should
* be excluded from certain kinds of queries. This is also used
* for language detection
* @var array
*/
public static $stop_words = ['como', 'I', 'seu', 'ele', 'foi', 'para', 'em',
'são', 'com', 'eles', 'ser', 'em', 'uma', 'tem', 'este',
'partir', 'de', 'por', 'quente', 'palavra', 'mas',
'que', 'alguns', 'é', 'ele', 'você', 'ou', 'teve',
'o', 'a', 'e', 'uma', 'em', 'nós', 'lata', 'fora',
'outro', 'foram', 'que', 'fazer', 'seu', 'tempo', 'se',
'vontade', 'como', 'disse', 'uma', 'cada', 'dizer', 'faz',
'conjunto', 'três', 'quer', 'ar', 'bem', 'também', 'jogar',
'pequeno', 'fim', 'colocar', 'casa', 'ler', 'mão', 'port',
'grande', 'soletrar', 'adicionar', 'mesmo', 'terra', 'aqui',
'necessário', 'grande', 'alto', 'tais', 'siga', 'ato',
'perguntar', 'homens', 'mudança', 'fui', 'luz',
'tipo', 'off', 'precisa', 'casa', 'imagem', 'tentar', 'nós',
'novamente', 'animais', 'ponto', 'mãe', 'mundo', 'perto',
'construir', 'auto', 'terra', 'pai'];
/**
* Phrases we would like yioop to rewrite before performing a query
* @var array
*/
public static $semantic_rewrites = [];
/**
* storage used in computing the stem
* @var string
*/
private static $buffer;
/**
* Index of the current end of the word at the current state of computing
* its stem
* @var int
*/
private static $k;
/**
* R1 is the region in the word after the first non-vowel following
* a vowel, or is the null region at the end of the word if there
* is no such non-vowel
* @var string
*/
private static $r1 = "";
/**
* R2 is the region in the R1 after the first non-vowel following a vowel,
* or is the null region at the end of the word if there is no non-vowel
* @var string
*/
private static $r2 = "";
/**
* If the second letter is a consonant, RV is the region after the next
* following vowel, or if the first two letters are vowels, RV is the
* region after the next consonant, and otherwise (consonant-vowel case)
* RV is the region after the third letter.
* @var string
*/
private static $rv = "";
/**
* Removes the stop words from the page (used for Word Cloud generation
* and language detection)
*
* @param mixed $data either a string or an array of string to remove
* stop words from
* @return mixed $data with no stop words
*/
public static function stopwordsRemover($data)
{
static $pattern = "";
if (empty($pattern)) {
$pattern = '/\b(' . implode('|', self::$stop_words) . ')\b/u';
}
$data = preg_replace($pattern, '', $data);
return $data;
}
/**
* Stub function which could be used for a word segmenter.
* Such a segmenter on input thisisabunchofwords would output
* this is a bunch of words
*
* @param string $pre_segment before segmentation
* @return string should return string with words separated by space
* in this case does nothing
*/
public static function segment($pre_segment)
{
return $pre_segment;
}
/**
* Computes the stem of an Portuguese word
* For example, química, químicas, químico, químicos
* all have químic as a stem
*
* @param string $word the string to stem
* @return string the stem of $words
*/
public static function stem($word)
{
self::$buffer = $word;
self::$k = strlen($word) - 1;
if (self::$k <= 1) { return $word; }
$word = str_ireplace("ã", "a~", $word);
$word = str_ireplace("õ", "o~", $word);
self::$r1 = self::findR1($word);
self::$r2 = self::findR1(self::$r1);
self::findRV($word);
$temp_word = self::step1($word);
if ($temp_word == $word){
$temp_word = self::step2($word);
}
if ($temp_word != $word){
self::findRV($temp_word);
$temp_word = self::step3($temp_word);
}else{
$temp_word = self::step4($temp_word);
self::findRV($temp_word);
}
$temp_word = self::step5($temp_word);
$temp_word = str_ireplace("a~", "ã", $temp_word);
$temp_word = str_ireplace("o~", "õ", $temp_word);
self::$rv = "";
$word = $temp_word;
return $word;
}
/**
* Standard Suffix Removal Step
* It search for longest suffix from given set and remove
* if found
*
* @param string $word the string to suffix removal
* @return processed string
*/
private static function step1($word)
{
$suffix_set = ['eza','ezas','ico','ica','icos','icas','ismo',
'ismos','ável','ível','ista','istas','oso','osa',
'osos','osas','amento','amentos','imento','imentos',
'adora','ador','aça~o','adoras','adores','aço~es',
'ante','antes','ância'];
$regex = "/[a-zA-Z~]*(eza|ezas|ico|ica|icos|icas|ismo|ismos|ável|ível
|ista|istas|oso|osa|osos|osas|amento|amentos|imento
|imentos|adora|ador|aça~o|adoras|adores|aço~es|ante
|antes|ância)";
foreach ($suffix_set as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)) {
$word = substr($word,0,-strlen($value));
break;
}
}
$special_suffix = ['logía' , 'logías'];
foreach ($special_suffix as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)){
$word = substr($word,0,-strlen($value))."log";
break;
}
}
$special_suffix = ['ución','uciones'];
foreach ($special_suffix as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)) {
$word = substr($word,0,-strlen($value))."u";
break;
}
}
$special_suffix = ['ência','ências'];
foreach ($special_suffix as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)){
$word = substr($word,0,-strlen($value))."ente";
break;
}
}
$special_suffix = ['ativamente','ivamente','osamente','icamente',
'adamente','antemente','avelmente','ívelmente'];
$is_removed = false;
foreach ($special_suffix as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)) {
$word = substr($word,0,-strlen($value));
$is_removed = true;
break;
}
}
if (!$is_removed) {
$is_removed = false;
$value = "amente";
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r1)) {
$word = substr($word,0,-strlen($value));
$is_removed = true;
}
if (!$is_removed) {
$value = "mente";
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)){
$word = substr($word,0,-strlen($value));
$is_removed = true;
}
}
}
$special_suffix = ['abilidades','icidades','ividades','abilidade',
'icidade','ividade','idades','idade'];
foreach ($special_suffix as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)) {
$word = substr($word,0,-strlen($value));
break;
}
}
$special_suffix = ['ativa','ativo','ativas','ativos','iva','ivo',
'ivas','ivos'];
foreach ($special_suffix as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$r2)){
$word = substr($word,0,-strlen($value));
break;
}
}
$special_suffix = ['iras','ira'];
foreach ($special_suffix as $value) {
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$rv)
&& preg_match("/[a-zA-Z~]*(eiras|eira)$/",$word)) {
$word = substr($word,0,-strlen($value))."ir";
break;
}
}
return $word;
}
/**
* Verb Suffix Removal Step
* If step 1 does not change anything than this function
* will be called
*
* It will also check for longest suffix from the suffix set
* Remove if found
*
* @param string $word the string to suffix removal
* @return processed string
*/
private static function step2($word)
{
$suffix_set = ["aríamos","eríamos","iríamos","ássemos",
"êssemos","íssemos","aríeis","eríeis","iríeis","ásseis",
"ésseis","ísseis","áramos","éramos","íramos","ávamos",
"aremos","eremos","iremos","ariam","eriam","iriam",
"assem","essem","issem","ara~o","era~o","ira~o","arias",
"erias","irias","ardes","erdes","irdes","asses","esses",
"isses","astes","estes","istes","áreis","areis","éreis",
"ereis","íreis","ireis","áveis","íamos","armos","ermos","irmos",
"aria","eria","iria","asse","esse","isse","aste","este","iste",
"arei","erei","irei","aram","eram","iram","avam","arem","erem",
"irem","ando","endo","indo","adas","idas","arás","aras","erás",
"eras","irás","avas","ares","eres","ires","íeis","ados","idos",
"ámos","amos","emos","imos","iras","ada","ida","ará","ara","erá",
"era","irá","ava","iam","ado","ido","ias","ais","eis","ira","ia",
"ei","am","em","ar","er","ir","as","es","is","eu","iu","ou"];
foreach ($suffix_set as $value){
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$rv)) {
$word = substr($word,0,-strlen($value));
break;
}
}
return $word;
}
/**
* Delete suffix i if in RV and preceded by c
*
* @param string $word the string to suffix removal
* @return processed string
*/
private static function step3($word)
{
$regex = "/[a-zA-Z~]*(ci)$/";
if (preg_match($regex, $word)) {
$regex = "/(i)[a-zA-Z~]*$/";
if (preg_match($regex, self::$rv)) {
$word = substr($word,0,-1);
}
}
return $word;
}
/**
* Residual suffix
* If the word ends with one of [os a i o á í ó]
* in RV
*
* @param string $word the string to suffix removal
* @return processed string
*/
private static function step4($word)
{
$regex = "/[a-zA-Z~]*(os)$/";
if (preg_match($regex, self::$rv)){
$word = substr($word,0,-2);
}else{
$regex = "/[a-zA-Z~]*(a|i|o)$/";
if (preg_match($regex, self::$rv)){
$word = substr($word,0,-1);
}else{
$regex = "/[a-zA-Z~]*(á|í|ó)$/";
if (preg_match($regex, self::$rv)){
$word = substr($word,0,-2);
}
}
}
return $word;
}
/**
* Residual suffix
* If the word ends with one of [e é ê]
* in RV
*
* @param string $word the string to suffix removal
* @return processed string
*/
private static function step5($word)
{
if (preg_match("/[a-zA-Z~]*(ç)$/", $word)){
$word = substr($word,0,-2)."c";
return $word;
}
$special_suffix = ["gue","cie"];
foreach ($special_suffix as $value){
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, $word)) {
$value = substr($value,1,strlen($value));
$regex = "/[a-zA-Z~]*($value)[a-zA-Z~]*$/";
if (preg_match($regex, self::$rv)){
$word = substr($word, 0, -2);
return $word;
}
}
}
$special_suffix = ["gué","guê","cié","ciê"];
foreach ($special_suffix as $value){
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, $word)) {
$value = substr($value, 1, strlen($value));
$regex = "/[a-zA-Z~]*($value)$/";
if (preg_match($regex, self::$rv)){
$word = substr($word, 0, -3);
return $word;
}
}
}
if (preg_match("/[a-zA-Z~]*(e)$/", $word)
&& preg_match("/[a-zA-Z~]*(e)[a-zA-Z~]*$/", self::$rv)){
$word = substr($word, 0, -1);
return $word;
}
if (preg_match("/[a-zA-Z~]*(é|ê)$/", $word)
&& preg_match("/[a-zA-Z~]*(é|ê)[a-zA-Z~]*$/", self::$rv)){
$word = substr($word, 0, -2);
return $word;
}
return $word;
}
/**
* This method will find R1 region in the $word
* R1 is the region after the first non-vowel following a vowel, or is
* the null region at the end of the word if there is no such non-vowel
*
* @param string $word the Portuguese word to find R1 within
* @return string $r1 region
*/
private static function findR1($word)
{
$word_length = mb_strlen($word);
$vowel = self::mbStringToArray("aeiouáéíóúâêô");
$first_vowel = false;
$second_vowel = false;
$first_consonent = false;
$second_consonent = false;
$r1 = "";
$word_array = self::mbStringToArray($word);
$i=0;
for ($i=0; $i<$word_length; $i++) {
if (in_array($word_array[$i],$vowel)) {
if ($first_vowel) {
if ($first_consonent) {
break;
}
}
$first_vowel = true;
} else {
if ($first_vowel) {
if ($first_consonent ){
break;
}
$first_consonent = true;
}
}
}
return mb_substr($word, $i, mb_strlen($word));
}
/**
* This method will find RV region in the $word
* If the second letter is a consonant,
* RV is the region after the next following vowel, or
* if the first two letters are vowels,
* RV is the region after the next consonant,
* and otherwise (consonant-vowel case)
* RV is the region after the third letter.
*
* @param string $word the Portuguese word to find RV within
* @return string $rv region
*/
private static function findRV($word)
{
$vowel = self::mbStringToArray("aeiouáéíóúâêô");
$word_array = self::mbStringToArray($word);
if (!isset($word_array[1]) || !in_array($word_array[1], $vowel)){
$word_length = mb_strlen($word);
$i = 2;
for ($i = 2; $i < $word_length; $i++) {
if (in_array($word_array[$i],$vowel)){
$i++;
break;
}
}
self::$rv = mb_substr($word, $i, mb_strlen($word));
} else if (in_array($word_array[0], $vowel)
&& in_array($word_array[1],$vowel)) {
$word_length = mb_strlen($word);
for ($i = 2; $i < $word_length; $i++){
if (!in_array($word_array[$i],$vowel)){
self::$rv = mb_substr($word, $i + 1, mb_strlen($word));
break;
}
}
} else if (!in_array($word_array[0], $vowel)
&& in_array($word_array[1],$vowel)){
self::$rv = mb_substr($word, 3, mb_strlen($word));
}
}
/**
* This method will break-up a multibyte string into its individual
* characters and generate an array of characters
*
* @param string $string of multibyte characters to break-up
* @return array of multibyte characters
*/
private static function mbStringToArray($string)
{
$len = mb_strlen($string);
$array = [];
while($len) {
$array[] = mb_substr($string,0, 1, "UTF-8");
$string = mb_substr($string, 1, $len,"UTF-8");
$len = mb_strlen($string);
}
return $array;
}
}
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