original_string: protected static function psr_classloader($class) {
          // Iterate through each PSR-4 namespace prefix.
          foreach (self::$psr4namespaces as $prefix => $path) {
              $file = self::get_class_file($class, $prefix, $path, array('\\'));
              if (!empty($file) && file_exists($file)) {
                  return $file;
              }
          }
  
          // Iterate through each PSR-0 namespace prefix.
          foreach (self::$psr0namespaces as $prefix => $path) {
              $file = self::get_class_file($class, $prefix, $path, array('\\', '_'));
              if (!empty($file) && file_exists($file)) {
                  return $file;
              }
          }
  
          return false;
      }
code: protected static function psr_classloader($class) {
          // Iterate through each PSR-4 namespace prefix.
          foreach (self::$psr4namespaces as $prefix => $path) {
              $file = self::get_class_file($class, $prefix, $path, array('\\'));
              if (!empty($file) && file_exists($file)) {
                  return $file;
              }
          }
  
          // Iterate through each PSR-0 namespace prefix.
          foreach (self::$psr0namespaces as $prefix => $path) {
              $file = self::get_class_file($class, $prefix, $path, array('\\', '_'));
              if (!empty($file) && file_exists($file)) {
                  return $file;
              }
          }
  
          return false;
      }
code_tokens: protected static function psr_classloader ( $ class ) { // Iterate through each PSR-4 namespace prefix. foreach ( self :: $ psr4namespaces as $ prefix => $ path ) { $ file = self :: get_class_file ( $ class , $ prefix , $ path , array ( '\\' ) ) ; if ( ! empty ( $ file ) && file_exists ( $ file ) ) { return $ file ; } } // Iterate through each PSR-0 namespace prefix. foreach ( self :: $ psr0namespaces as $ prefix => $ path ) { $ file = self :: get_class_file ( $ class , $ prefix , $ path , array ( '\\' , '_' ) ) ; if ( ! empty ( $ file ) && file_exists ( $ file ) ) { return $ file ; } } return false ; }
docstring: Return the path to a class from our defined PSR-0 or PSR-4 standard namespaces on
  demand. Only returns paths to files that exist.
  
  Adapated from http://www.php-fig.org/psr/psr-4/examples/ and made PSR-0
  compatible.
  
  @param string $class the name of the class.
  @return string|bool The full path to the file defining the class. Or false if it could not be resolved or does not exist.
docstring_tokens: Return the path to a class from our defined PSR - 0 or PSR - 4 standard namespaces on demand . Only returns paths to files that exist .