Remove usage of empty function when possible

Author: alamirault

Parser/Parser.php

@@ -242,7 +242,7 @@ private function parseSimpleSelector(TokenStream $stream, bool $insideNegation =
                         }
                     }
 
-                    if (empty($arguments)) {
+                    if (!$arguments) {
                         throw SyntaxErrorException::unexpectedToken('at least one argument', $next);
                     }
 

Parser/Token.php

@@ -68,7 +68,7 @@ public function isDelimiter(array $values = []): bool
             return false;
         }
 
-        if (empty($values)) {
+        if (!$values) {
             return true;
         }
 

XPath/Translator.php

@@ -220,7 +220,7 @@ private function parseSelectors(string $css): array
         foreach ($this->shortcutParsers as $shortcut) {
             $tokens = $shortcut->parse($css);
 
-            if (!empty($tokens)) {
+            if ($tokens) {
                 return $tokens;
             }
         }