Virtual Dictionary Filesystem. That's what this is.
VDFS is a small proof-of-concept implementation for an in memory file system made of dictionaries.
The root is represented by a vdfs.Filesystem, which can be the parent of directories and files.
Directories can recursively parent files or other directories, ad infinitum.
As per a real file system, a file can't parent anything else. It's just a chunk of data.
Since this is a relatively new project, there isn't really any documentation, and the syntax isn't set in stone. Have a little read of the source if you're interested in working with it, though.