[PATCH] add `files-tree' data source

[David Bremner]

David Bremner <david at tethera.net> writes:

> +  (labels ((%make-path (iden1 iden2)
> +             (let* ((dir (pathname-directory location))
> +                    (name (pathname-name location))
> +                    (path (if name (append dir (list name)) dir)))
> +               (make-pathname :directory (append path (list iden1)) :name iden2)))

As soon as sent this I remembered I had a simpler version of this [1] that
just used #'ensure-directory-pathname. I'll wait to see if there are any
other improvements and send send a second version. 

[1]: (let ((path (ensure-directory-pathname (pathname-directory location)))) ...)