function step4 in Porter-Stemmer 5

Same name and namespace in other branches

1. 6 porterstemmer.module \step4()

Step 4

Parameters

string $word Word to stem:

1 call to step4()

stem in ./porterstemmer.module

Stems a word. Simple huh?

File

./porterstemmer.module, line 239

Code

function step4($word) {
  switch (substr($word, -2, 1)) {
    case 'a':
      replace($word, 'al', '', 1);
      break;
    case 'c':
      replace($word, 'ance', '', 1) or replace($word, 'ence', '', 1);
      break;
    case 'e':
      replace($word, 'er', '', 1);
      break;
    case 'i':
      replace($word, 'ic', '', 1);
      break;
    case 'l':
      replace($word, 'able', '', 1) or replace($word, 'ible', '', 1);
      break;
    case 'n':
      replace($word, 'ant', '', 1) or replace($word, 'ement', '', 1) or replace($word, 'ment', '', 1) or replace($word, 'ent', '', 1);
      break;
    case 'o':
      if (substr($word, -4) == 'tion' or substr($word, -4) == 'sion') {
        replace($word, 'ion', '', 1);
      }
      else {
        replace($word, 'ou', '', 1);
      }
      break;
    case 's':
      replace($word, 'ism', '', 1);
      break;
    case 't':
      replace($word, 'ate', '', 1) or replace($word, 'iti', '', 1);
      break;
    case 'u':
      replace($word, 'ous', '', 1);
      break;
    case 'v':
      replace($word, 'ive', '', 1);
      break;
    case 'z':
      replace($word, 'ize', '', 1);
      break;
  }
  return $word;
}