Following up #42.

- Removed redundant method SequenceMatcherHelper::arrayGetDefault().
- Renamed SequenceMatcherHelper to more generic name DiffUtils.
- Changed calls to SequenceMatcherHelper::arrayGetDefault() into
  comparison with null coalesce operator.
- Moved helper class from renderer directory to Diff directory.
- Changed namespaces to reflect above changes.

Author: DigiLive

lib/jblond/Diff/Renderer/SequenceMatcherHelper.php renamed to lib/jblond/Diff/DiffUtils.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace jblond\Diff\Renderer;
+namespace jblond\Diff;
 
 /**
  * Sequence matcher helper functions for Diff
@@ -13,34 +13,16 @@
  * @version 2.0.0
  * @link https://github.com/JBlond/php-diff
  */
-class SequenceMatcherHelper
+class DiffUtils
 {
-    /**
-     * Helper function that provides the ability to return the value for a key
-     * in an array of it exists, or if it doesn't then return a default value.
-     * Essentially cleaner than doing a series of if (isset()) {} else {} calls.
-     *
-     * @param array $array The array to search.
-     * @param string|int $key The key to check that exists.
-     * @param mixed $default The value to return as the default value if the key doesn't exist.
-     * @return mixed The value from the array if the key exists or otherwise the default.
-     */
-    protected function arrayGetDefault(array $array, $key, $default)
-    {
-        if (isset($array[$key])) {
-            return $array[$key];
-        }
-        return $default;
-    }
-
     /**
      * Sort an array by the nested arrays it contains. Helper function for getMatchingBlocks
      *
      * @param array $aArray First array to compare.
      * @param array $bArray Second array to compare.
      * @return int -1, 0 or 1, as expected by the usort function.
      */
-    protected function tupleSort(array $aArray, array $bArray): int
+    public static function tupleSort(array $aArray, array $bArray): int
     {
         $max = max(count($aArray), count($bArray));
         for ($counter = 0; $counter < $max; ++$counter) {

lib/jblond/Diff/SequenceMatcher.php

@@ -5,7 +5,6 @@
 namespace jblond\Diff;
 
 use InvalidArgumentException;
-use jblond\Diff\Renderer\SequenceMatcherHelper;
 
 /**
  * Sequence matcher for Diff
@@ -21,7 +20,7 @@
  * @version 2.0.0
  * @link https://github.com/JBlond/php-diff
  */
-class SequenceMatcher extends SequenceMatcherHelper
+class SequenceMatcher
 {
     /**
      * @var string|array Either a string or an array containing a callback function to determine
@@ -258,15 +257,15 @@ public function findLongestMatch(int $aLower, int $aUpper, int $bLower, int $bUp
 
         for ($i = $aLower; $i < $aUpper; ++$i) {
             $newJ2Len = [];
-            $jDict = $this->arrayGetDefault($this->b2j, $old[$i], $nothing);
+            $jDict = $this->b2j[$old[$i]] ?? $nothing;
             foreach ($jDict as $j) {
                 if ($j < $bLower) {
                     continue;
                 } elseif ($j >= $bUpper) {
                     break;
                 }
 
-                $k = $this->arrayGetDefault($j2Len, $j - 1, 0) + 1;
+                $k = ($j2Len[$j - 1] ?? 0) + 1;
                 $newJ2Len[$j] = $k;
                 if ($k > $bestSize) {
                     $bestI = $i - $k + 1;
@@ -413,7 +412,7 @@ public function getMatchingBlocks(): array
         usort(
             $matchingBlocks,
             function ($aArray, $bArray) {
-                return $this->tupleSort($aArray, $bArray);
+                return DiffUtils::tupleSort($aArray, $bArray);
             }
         );