On Wed, 18 Sep 2002, 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?
This is probably a non-issue. If you start trying to specify details like echoing, you might as well go into the details of which pixels are supposed to light up on the monitor, or how the teletype should behave. If you indicate leeway then implementors will probably "do the right thing" in all or nearly all cases. Note that the Report does not (really cannot) precisely specify what happens when multiple programs access the same file at once, or what happens when a program receives a SIGHUP signal (because its controlling terminal has disconnected) or all sorts of other things that are not really any of its business. David