X-Git-Url: http://www.aleph1.co.uk/gitweb/?a=blobdiff_plain;ds=sidebyside;f=web%2Fmodules%2Fcontrib%2Fporterstemmer%2Fsrc%2FPorter2.php;fp=web%2Fmodules%2Fcontrib%2Fporterstemmer%2Fsrc%2FPorter2.php;h=f26937ca79f06279ae9ea91f6e870c4c89573858;hb=5ca1b61ad2659177690cbde2cf7675f9c0d50491;hp=0000000000000000000000000000000000000000;hpb=4e1bfbf98b844da83b18aca92ef00f11a4735806;p=yaffs-website

diff --git a/web/modules/contrib/porterstemmer/src/Porter2.php b/web/modules/contrib/porterstemmer/src/Porter2.php
new file mode 100644
index 000000000..f26937ca7
--- /dev/null
+++ b/web/modules/contrib/porterstemmer/src/Porter2.php
@@ -0,0 +1,623 @@
+<?php
+
+namespace Drupal\porterstemmer;
+
+/**
+ * PHP Implementation of the Porter2 Stemming Algorithm.
+ *
+ * See http://snowball.tartarus.org/algorithms/english/stemmer.html .
+ */
+class Porter2 {
+
+  /**
+   * Computes the stem of the word.
+   *
+   * @return string
+   *   The word's stem.
+   */
+  public static function stem($word) {
+
+    $exceptions = array(
+      'skis' => 'ski',
+      'skies' => 'sky',
+      'dying' => 'die',
+      'lying' => 'lie',
+      'tying' => 'tie',
+      'idly' => 'idl',
+      'gently' => 'gentl',
+      'ugly' => 'ugli',
+      'early' => 'earli',
+      'only' => 'onli',
+      'singly' => 'singl',
+      'sky' => 'sky',
+      'news' => 'news',
+      'howe' => 'howe',
+      'atlas' => 'atlas',
+      'cosmos' => 'cosmos',
+      'bias' => 'bias',
+      'andes' => 'andes',
+    );
+
+    // Process exceptions.
+    if (isset($exceptions[$word])) {
+      $word = $exceptions[$word];
+    }
+    elseif (strlen($word) > 2) {
+      // Only execute algorithm on words that are longer than two letters.
+      $word = self::prepare($word);
+      $word = self::step0($word);
+      $word = self::step1a($word);
+      $word = self::step1b($word);
+      $word = self::step1c($word);
+      $word = self::step2($word);
+      $word = self::step3($word);
+      $word = self::step4($word);
+      $word = self::step5($word);
+    }
+    return strtolower($word);
+  }
+
+  /**
+   * Set initial y, or y after a vowel, to Y.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The prepared word.
+   */
+  protected static function prepare($word) {
+    $inc = 0;
+    if (strpos($word, "'") === 0) {
+      $word = substr($word, 1);
+    }
+    while ($inc <= strlen($word)) {
+      if (substr($word, $inc, 1) === 'y' && ($inc == 0 || self::isVowel($inc - 1, $word))) {
+        $word = substr_replace($word, 'Y', $inc, 1);
+      }
+      $inc++;
+    }
+    return $word;
+  }
+
+  /**
+   * Search for the longest among the "s" suffixes and removes it.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step0($word) {
+    $found = FALSE;
+    $checks = array("'s'", "'s", "'");
+    foreach ($checks as $check) {
+      if (!$found && self::hasEnding($word, $check)) {
+        $word = self::removeEnding($word, $check);
+        $found = TRUE;
+      }
+    }
+    return $word;
+  }
+
+  /**
+   * Handles various suffixes, of which the longest is replaced.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step1a($word) {
+    $found = FALSE;
+    if (self::hasEnding($word, 'sses')) {
+      $word = self::removeEnding($word, 'sses') . 'ss';
+      $found = TRUE;
+    }
+    $checks = array('ied', 'ies');
+    foreach ($checks as $check) {
+      if (!$found && self::hasEnding($word, $check)) {
+        // @todo: check order here.
+        $length = strlen($word);
+        $word = self::removeEnding($word, $check);
+        if ($length > 4) {
+          $word .= 'i';
+        }
+        else {
+          $word .= 'ie';
+        }
+        $found = TRUE;
+      }
+    }
+    if (self::hasEnding($word, 'us') || self::hasEnding($word, 'ss')) {
+      $found = TRUE;
+    }
+    // Delete if preceding word part has a vowel not immediately before the s.
+    if (!$found && self::hasEnding($word, 's') && self::containsVowel(substr($word, 0, -2))) {
+      $word = self::removeEnding($word, 's');
+    }
+    return $word;
+  }
+
+  /**
+   * Handles various suffixes, of which the longest is replaced.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step1b($word) {
+    $exceptions = array(
+      'inning',
+      'outing',
+      'canning',
+      'herring',
+      'earring',
+      'proceed',
+      'exceed',
+      'succeed',
+    );
+    if (in_array($word, $exceptions)) {
+      return $word;
+    }
+    $checks = array('eedly', 'eed');
+    foreach ($checks as $check) {
+      if (self::hasEnding($word, $check)) {
+        if (self::r($word, 1) !== strlen($word)) {
+          $word = self::removeEnding($word, $check) . 'ee';
+        }
+        return $word;
+      }
+    }
+    $checks = array('ingly', 'edly', 'ing', 'ed');
+    $second_endings = array('at', 'bl', 'iz');
+    foreach ($checks as $check) {
+      // If the ending is present and the previous part contains a vowel.
+      if (self::hasEnding($word, $check) && self::containsVowel(substr($word, 0, -strlen($check)))) {
+        $word = self::removeEnding($word, $check);
+        foreach ($second_endings as $ending) {
+          if (self::hasEnding($word, $ending)) {
+            return $word . 'e';
+          }
+        }
+        // If the word ends with a double, remove the last letter.
+        $double_removed = self::removeDoubles($word);
+        if ($double_removed != $word) {
+          $word = $double_removed;
+        }
+        elseif (self::isShort($word)) {
+          // If the word is short, add e (so hop -> hope).
+          $word .= 'e';
+        }
+        return $word;
+      }
+    }
+    return $word;
+  }
+
+  /**
+   * Replaces suffix y or Y with i if after non-vowel not @ word begin.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step1c($word) {
+    if ((self::hasEnding($word, 'y') || self::hasEnding($word, 'Y')) && strlen($word) > 2 && !(self::isVowel(strlen($word) - 2, $word))) {
+      $word = self::removeEnding($word, 'y');
+      $word .= 'i';
+    }
+    return $word;
+  }
+
+  /**
+   * Implements step 2 of the Porter2 algorithm.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step2($word) {
+    $checks = array(
+      "ization" => "ize",
+      "iveness" => "ive",
+      "fulness" => "ful",
+      "ational" => "ate",
+      "ousness" => "ous",
+      "biliti" => "ble",
+      "tional" => "tion",
+      "lessli" => "less",
+      "fulli" => "ful",
+      "entli" => "ent",
+      "ation" => "ate",
+      "aliti" => "al",
+      "iviti" => "ive",
+      "ousli" => "ous",
+      "alism" => "al",
+      "abli" => "able",
+      "anci" => "ance",
+      "alli" => "al",
+      "izer" => "ize",
+      "enci" => "ence",
+      "ator" => "ate",
+      "bli" => "ble",
+      "ogi" => "og",
+    );
+    foreach ($checks as $find => $replace) {
+      if (self::hasEnding($word, $find)) {
+        if (self::inR1($word, $find)) {
+          $word = self::removeEnding($word, $find) . $replace;
+        }
+        return $word;
+      }
+    }
+    if (self::hasEnding($word, 'li')) {
+      if (strlen($word) > 4 && self::validLi(self::charAt(-3, $word))) {
+        $word = self::removeEnding($word, 'li');
+      }
+    }
+    return $word;
+  }
+
+  /**
+   * Implements step 3 of the Porter2 algorithm.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step3($word) {
+    $checks = array(
+      'ational' => 'ate',
+      'tional' => 'tion',
+      'alize' => 'al',
+      'icate' => 'ic',
+      'iciti' => 'ic',
+      'ical' => 'ic',
+      'ness' => '',
+      'ful' => '',
+    );
+    foreach ($checks as $find => $replace) {
+      if (self::hasEnding($word, $find)) {
+        if (self::inR1($word, $find)) {
+          $word = self::removeEnding($word, $find) . $replace;
+        }
+        return $word;
+      }
+    }
+    if (self::hasEnding($word, 'ative')) {
+      if (self::inR2($word, 'ative')) {
+        $word = self::removeEnding($word, 'ative');
+      }
+    }
+    return $word;
+  }
+
+  /**
+   * Implements step 4 of the Porter2 algorithm.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step4($word) {
+    $checks = array(
+      'ement',
+      'ment',
+      'ance',
+      'ence',
+      'able',
+      'ible',
+      'ant',
+      'ent',
+      'ion',
+      'ism',
+      'ate',
+      'iti',
+      'ous',
+      'ive',
+      'ize',
+      'al',
+      'er',
+      'ic',
+    );
+    foreach ($checks as $check) {
+      // Among the suffixes, if found and in R2, delete.
+      if (self::hasEnding($word, $check)) {
+        if (self::inR2($word, $check)) {
+          if ($check !== 'ion' || in_array(self::charAt(-4, $word), array('s', 't'))) {
+            $word = self::removeEnding($word, $check);
+          }
+        }
+        return $word;
+      }
+    }
+    return $word;
+  }
+
+  /**
+   * Implements step 5 of the Porter2 algorithm.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function step5($word) {
+    if (self::hasEnding($word, 'e')) {
+      // Delete if in R2, or in R1 and not preceded by a short syllable.
+      if (self::inR2($word, 'e') || (self::inR1($word, 'e') && !self::isShortSyllable($word, strlen($word) - 3))) {
+        $word = self::removeEnding($word, 'e');
+      }
+      return $word;
+    }
+    if (self::hasEnding($word, 'l')) {
+      // Delete if in R2 and preceded by l.
+      if (self::inR2($word, 'l') && self::charAt(-2, $word) == 'l') {
+        $word = self::removeEnding($word, 'l');
+      }
+    }
+    return $word;
+  }
+
+  /**
+   * Removes certain double consonants from the word's end.
+   *
+   * @param string $word
+   *   The word to stem.
+   *
+   * @return string $word
+   *   The modified word.
+   */
+  protected static function removeDoubles($word) {
+    $doubles = array('bb', 'dd', 'ff', 'gg', 'mm', 'nn', 'pp', 'rr', 'tt');
+    foreach ($doubles as $double) {
+      if (substr($word, -2) == $double) {
+        $word = substr($word, 0, -1);
+        break;
+      }
+    }
+    return $word;
+  }
+
+  /**
+   * Checks whether a character is a vowel.
+   *
+   * @param int $position
+   *   The character's position.
+   * @param string $word
+   *   The word in which to check.
+   * @param string[] $additional
+   *   (optional) Additional characters that should count as vowels.
+   *
+   * @return bool
+   *   TRUE if the character is a vowel, FALSE otherwise.
+   */
+  protected static function isVowel($position, $word, $additional = array()) {
+    $vowels = array_merge(array('a', 'e', 'i', 'o', 'u', 'y'), $additional);
+    return in_array(self::charAt($position, $word), $vowels);
+  }
+
+  /**
+   * Retrieves the character at the given position.
+   *
+   * @param int $position
+   *   The 0-based index of the character. If a negative number is given, the
+   *   position is counted from the end of the string.
+   * @param string $word
+   *   The word from which to retrieve the character.
+   *
+   * @return string
+   *   The character at the given position, or an empty string if the given
+   *   position was illegal.
+   */
+  protected static function charAt($position, $word) {
+    $length = strlen($word);
+    if (abs($position) >= $length) {
+      return '';
+    }
+    if ($position < 0) {
+      $position += $length;
+    }
+    return $word[$position];
+  }
+
+  /**
+   * Determines whether the word ends in a "vowel-consonant" suffix.
+   *
+   * Unless the word is only two characters long, it also checks that the
+   * third-last character is neither "w", "x" nor "Y".
+   *
+   * @param int|null $position
+   *   (optional) If given, do not check the end of the word, but the character
+   *   at the given position, and the next one.
+   *
+   * @return bool
+   *   TRUE if the word has the described suffix, FALSE otherwise.
+   */
+  protected static function isShortSyllable($word, $position = NULL) {
+    if ($position === NULL) {
+      $position = strlen($word) - 2;
+    }
+    // A vowel at the beginning of the word followed by a non-vowel.
+    if ($position === 0) {
+      return self::isVowel(0, $word) && !self::isVowel(1, $word);
+    }
+    // Vowel followed by non-vowel other than w, x, Y and preceded by
+    // non-vowel.
+    $additional = array('w', 'x', 'Y');
+    return !self::isVowel($position - 1, $word) && self::isVowel($position, $word) && !self::isVowel($position + 1, $word, $additional);
+  }
+
+  /**
+   * Determines whether the word is short.
+   *
+   * A word is called short if it ends in a short syllable and if R1 is null.
+   *
+   * @return bool
+   *   TRUE if the word is short, FALSE otherwise.
+   */
+  protected static function isShort($word) {
+    return self::isShortSyllable($word) && self::r($word, 1) == strlen($word);
+  }
+
+  /**
+   * Determines the start of a certain "R" region.
+   *
+   * R is a region after the first non-vowel following a vowel, or end of word.
+   *
+   * @param int $type
+   *   (optional) 1 or 2. If 2, then calculate the R after the R1.
+   *
+   * @return int
+   *   The R position.
+   */
+  protected static function r($word, $type = 1) {
+    $inc = 1;
+    if ($type === 2) {
+      $inc = self::r($word, 1);
+    }
+    elseif (strlen($word) > 5) {
+      $prefix_5 = substr($word, 0, 5);
+      if ($prefix_5 === 'gener' || $prefix_5 === 'arsen') {
+        return 5;
+      }
+      if (strlen($word) > 5 && substr($word, 0, 6) === 'commun') {
+        return 6;
+      }
+    }
+
+    while ($inc <= strlen($word)) {
+      if (!self::isVowel($inc, $word) && self::isVowel($inc - 1, $word)) {
+        $position = $inc;
+        break;
+      }
+      $inc++;
+    }
+    if (!isset($position)) {
+      $position = strlen($word);
+    }
+    else {
+      // We add one, as this is the position AFTER the first non-vowel.
+      $position++;
+    }
+    return $position;
+  }
+
+  /**
+   * Checks whether the given string is contained in R1.
+   *
+   * @param string $string
+   *   The string.
+   *
+   * @return bool
+   *   TRUE if the string is in R1, FALSE otherwise.
+   */
+  protected static function inR1($word, $string) {
+    $r1 = substr($word, self::r($word, 1));
+    return strpos($r1, $string) !== FALSE;
+  }
+
+  /**
+   * Checks whether the given string is contained in R2.
+   *
+   * @param string $string
+   *   The string.
+   *
+   * @return bool
+   *   TRUE if the string is in R2, FALSE otherwise.
+   */
+  protected static function inR2($word, $string) {
+    $r2 = substr($word, self::r($word, 2));
+    return strpos($r2, $string) !== FALSE;
+  }
+
+  /**
+   * Checks whether the word ends with the given string.
+   *
+   * @param string $string
+   *   The string.
+   *
+   * @return bool
+   *   TRUE if the word ends with the given string, FALSE otherwise.
+   */
+  protected static function hasEnding($word, $string) {
+    $length = strlen($string);
+    if ($length > strlen($word)) {
+      return FALSE;
+    }
+    return (substr_compare($word, $string, -1 * $length, $length) === 0);
+  }
+
+  /**
+   * Removes a given string from the end of the current word.
+   *
+   * Does not check whether the ending is actually there.
+   *
+   * @param string $string
+   *   The ending to remove.
+   */
+  protected static function removeEnding($word, $string) {
+    return substr($word, 0, -strlen($string));
+  }
+
+  /**
+   * Checks whether the given string contains a vowel.
+   *
+   * @param string $string
+   *   The string to check.
+   *
+   * @return bool
+   *   TRUE if the string contains a vowel, FALSE otherwise.
+   */
+  protected static function containsVowel($string) {
+    $inc = 0;
+    $return = FALSE;
+    while ($inc < strlen($string)) {
+      if (self::isVowel($inc, $string)) {
+        $return = TRUE;
+        break;
+      }
+      $inc++;
+    }
+    return $return;
+  }
+
+  /**
+   * Checks whether the given string is a valid -li prefix.
+   *
+   * @param string $string
+   *   The string to check.
+   *
+   * @return bool
+   *   TRUE if the given string is a valid -li prefix, FALSE otherwise.
+   */
+  protected static function validLi($string) {
+    return in_array($string, array(
+      'c',
+      'd',
+      'e',
+      'g',
+      'h',
+      'k',
+      'm',
+      'n',
+      'r',
+      't',
+    ));
+  }
+
+}