Soundex - Correct and Train

correct.php

<?php

function correct($word, $dic) {
  if (array_key_exists($word, $dic)) {
    return $word;
  }

  $search_result = $dic[soundex($word)];

  foreach ($search_result as $key => &$res) {
    $dist = levenshtein($key, $word);
    // consider just distance equals to 1 (the best) or 2
    if ($dist == 1 || $dist == 2) {
      $res = $res / $dist;
    }
    // discard all the other candidates that have distances other than 1 and 2
    // from the original word
    else {
      unset($search_result[$key]);
    }
  }

  // reverse sorting of the words by frequence
  arsort($search_result);

  // return the first key of the array (which will be the word suggested)
  foreach ($search_result as $key => $res) {
    return $key;
  }
}

train.php

<?php
 
function train($file = 'big.txt') {
  $contents = file_get_contents($file);
  // get all strings of word letters
  preg_match_all('/\w+/', $contents, $matches);
  unset($contents);
  $dictionary = array();
  foreach ($matches[0] as $word) {
    $word = strtolower($word);
    $soundex_key = soundex($word);
    if (!isset($dictionary[$soundex_key][$word])) {
      $dictionary[$soundex_key][$word] = 0;
    }
 
    $dictionary[$soundex_key][$word] += 1;
  }
  unset($matches);
  return $dictionary;
}