> It's signature is:
>
>> (directory-files/[dir dotfiles?]/)
>
> Seems to me that /dir/ and /dotfiles?/ should be independent optional
> variables, if you specify a directory, you shouldn't have to also
> specify if you want to see the dot files.

Here's how Gambit does it:

(directory-files [path-or-settings])	procedure

This procedure returns the list of the files in a directory. The
argument path-or-settings is either a string denoting a filesystem path
to a directory or a list of settings which must contain a path: setting.
If it is not specified, path-or-settings defaults to the current
directory (the value bound to the current-directory parameter object).
Here are the settings allowed:

     path: string

     This setting indicates the location of the directory in the
filesystem. There is no default value for this setting.

     ignore-hidden: ( #f | #t | dot-and-dot-dot )

     ...