Haskell 98: Behaviour of hClose

Glynn Clements glynn.clements@virgin.net
Wed, 18 Sep 2002 20:22:43 +0100


Simon Peyton-Jones wrote:

> What I intended was
> 	a simple interactive Haskell program should behave the same 
> 	on any OS/environment
> 
> What you and Ross seem to be saying is
> 	no, the behaviour of the program can, and should, depend 
> 	on the OS/environment
> 
> If that's the consensus I'll happily leave echoing behaviour
> unspecified. Remember, that means that a conforming implementation can
> do whatever it pleases, and hence it's impossible to write a portable
> interactive Haskell program.  Is that you what you intend?

The behaviour of the program itself doesn't depend upon the
environment, but the overall user-visible behaviour of the system when
running that program does.

Any echoing, line editing, etc which is performed by the OS' terminal
driver is not part of the program's behaviour.

A conforming implementation should *not* do whatever it pleases. If
necessary, it should be explictly specified that the terminal settings
are left untouched.

-- 
Glynn Clements <glynn.clements@virgin.net>