I'm relatively new to ocaml and very new to this list. Browsing thru recent
discussion about standard IO structure, I felt that discussion was cycled 
over what signature of the "universal" class should look like, so it would 
satisfy all possible needs.

However looks like prospective users, of this new IO, have rather 
contradictive requirements to the IO in general. And I'm thinking could 
standard IO only to provide basic signature of the IO modules and framework 
for layered IO.  Doing so additional functionality could be added 
incrementally, without affection core IO and achieving interoperability 
between different libraries which are using that IO.

Last day or two I was playing with ocaml and ocaml module system, and 
sketched some variant of basic IO. This sketch based on imperative 
streams, where stream is module parameterized by the symbol type. However 
blocked based IO is also supported, test code includes naive functors to 
translate from a block based IO to a stream IO.

If you felt interested, please look into the attached file io.ml. 

In the file you would found wrappers for Pervasive file IO, rudimentary
socket I/O, naive UTF8 filter and generic I/O algorithms. At the end
of file there are several test cases to exercise I/O extensibility.

File is self sufficient example and one should be able to compile it or run
in the toplevel. 
	

Regards,
Vladimir