Re: [Ocaml-lib-devel] IO oo wrappers

[John G. <jgo...@co...>]

On Sun, Apr 25, 2004 at 10:41:26PM +0200, Nicolas Cannasse wrote:
> Here's some OO wrappers proposal for IO module.
> 
> As Yamagata Yoriyuki suggested, theses can be useful in order to provide
> ExtLib IO compatibility without the need to add a dependency to IO module

I've just started looking at this project, but I am confused about what
IO module you're talking about -- I don't see one at
http://ocaml-lib.sourceforge.net/doc/.

In any case, I have thought about some sort of generic wrapper for I/O
as well.  In OCaml, there are already two different I/O capabilities in
the standard distribution -- the channels in Pervasives, and the Unix
module's capabilities.

It would be useful to, IMHO, define a standardized interface that can be
implemented for both these and other types.  For instance, one might
have:

ReadableFile
  Methods: read(), readline(), readlines(), etc.
WritableFile
  Methods: write(), flush(), truncate(), etc.
SeekableFile
  Methods: seek(), tell(), etc.

Any given implementation could inherit and implement one or both of
ReadableFile and optionally SeekableFile.  There would be other benefits
to this as well.  For instance, one could implement a virtual file
object using Buffers.  This would be similar in concept to Python's
StringIO, which lets you pass a file-like object to any function
expecting to do I/O; that I/O is emulated, and the contents of the
string can be accessed later.

-- John