Code updates

Author: javiereguiluz

Dumper.php

@@ -169,7 +169,7 @@ private function getBlockIndentationIndicator(string $value): string
         // http://www.yaml.org/spec/1.2/spec.html#id2793979
         foreach ($lines as $line) {
             if ('' !== trim($line, ' ')) {
-                return (' ' === substr($line, 0, 1)) ? (string) $this->indentation : '';
+                return str_starts_with($line, ' ') ? (string) $this->indentation : '';
             }
         }
 

Escaper.php

@@ -80,7 +80,7 @@ public static function requiresSingleQuoting(string $value): bool
 
         // Determines if the PHP value contains any single characters that would
         // cause it to require single quoting in YAML.
-        return 0 < preg_match('/[ \s \' " \: \{ \} \[ \] , & \* \# \?] | \A[ \- ? | < > = ! % @ ` \p{Zs}]/xu', $value);
+        return 0 < preg_match('/[\s\'"\:\{\}\[\],&\*\#\?] | \A[\-?|<>=!%@`\p{Zs}]/xu', $value);
     }
 
     /**