Leverage arrow function syntax for closure

Author: tigitz

Command/LintCommand.php

@@ -240,12 +240,10 @@ private function getParser(): Parser
 
     private function getDirectoryIterator(string $directory): iterable
     {
-        $default = function ($directory) {
-            return new \RecursiveIteratorIterator(
-                new \RecursiveDirectoryIterator($directory, \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::FOLLOW_SYMLINKS),
-                \RecursiveIteratorIterator::LEAVES_ONLY
-            );
-        };
+        $default = fn ($directory) => new \RecursiveIteratorIterator(
+            new \RecursiveDirectoryIterator($directory, \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::FOLLOW_SYMLINKS),
+            \RecursiveIteratorIterator::LEAVES_ONLY
+        );
 
         if (null !== $this->directoryIteratorProvider) {
             return ($this->directoryIteratorProvider)($directory, $default);
@@ -256,9 +254,7 @@ private function getDirectoryIterator(string $directory): iterable
 
     private function isReadable(string $fileOrDirectory): bool
     {
-        $default = function ($fileOrDirectory) {
-            return is_readable($fileOrDirectory);
-        };
+        $default = is_readable(...);
 
         if (null !== $this->isReadableProvider) {
             return ($this->isReadableProvider)($fileOrDirectory, $default);

Unescaper.php

@@ -45,9 +45,7 @@ public function unescapeSingleQuotedString(string $value): string
      */
     public function unescapeDoubleQuotedString(string $value): string
     {
-        $callback = function ($match) {
-            return $this->unescapeCharacter($match[0]);
-        };
+        $callback = fn ($match) => $this->unescapeCharacter($match[0]);
 
         // evaluate the string
         return preg_replace_callback('/'.self::REGEX_ESCAPED_CHARACTER.'/u', $callback, $value);