code: func fileAndExt(in string, b filepathPathBridge) (name string, ext string) {
  	ext = b.Ext(in)
  	base := b.Base(in)
  
  	return extractFilename(in, ext, base, b.Separator()), ext
  }
docs: // FileAndExt returns the filename and any extension of a file path as
  // two separate strings.
  //
  // If the path, in, contains a directory name ending in a slash,
  // then both name and ext will be empty strings.
  //
  // If the path, in, is either the current directory, the parent
  // directory or the root directory, or an empty string,
  // then both name and ext will be empty strings.
  //
  // If the path, in, represents the path of a file without an extension,
  // then name will be the name of the file and ext will be an empty string.
  //
  // If the path, in, represents a filename with an extension,
  // then name will be the filename minus any extension - including the dot
  // and ext will contain the extension - minus the dot.