Re: [Ocaml-lib-devel] Unzip module and filesystems

[Jere S. <xm...@xm...>]

On Fri, Jul 23, 2004 at 10:09:32PM +0200, Nicolas Cannasse wrote:
>The Unzip module is now part of ExtLib !
>You can deflate your TGZ and ZIP with pure OCaml code only !
>Enjoy,

Cool, thanks!

I've still to see your code in the CVS (does sourceforge always have a delay
after commit for the changes to show up?) but a few questions. So you have
unzip, how about a zip? It's always handy to pack stuff as well.

And how far does the current module go? Can it unpack whole zip files with
several files in them?

Which brings me to another curiosity I've been having. After looking at the
ocaml core library I was missing abstract files (so I could implement my
own, given an interface). Well, Extlib has that and great. But how about an
abstract filesystem? Something along the lines of:
---
class base_filesys :
	object
	method exists : string -> bool
	method size : string -> int

	method chdir : string -> unit
	method cwd : unit -> string
	end

class ['a] i_filesys :
	object
	inherit base_filesys

	method open_in : string -> 'a
	end

class ['a] o_filesys :
	object
	inherit base_filesys

	method delete : string -> unit

	method open_out : string -> 'a
	end

class ['a,'b] io_filesys :
	object
	inherit ['a] i_filesys
	inherit ['b] o_filesys
	end
---
That way you could do easy wrappings for filesystems. Useful things like:
 - Use a ZIP as a filesystem (input only if you please)
 - Use remote filesystem
 - Implement sandboxing (filesystem inside a filesystem, like prevent the
application accidentally accessing some part outside the given directory)

What do you guys think?

-- 
Jere Sanisalo [xm...@xm...] - http://www.xmunkki.org/