patch for `interact'

[Malcolm Wallace]

> > There is a bug in Dec2001 Hugs (and earlier releases too) which causes
> > the Prelude function `interact' to behave unexpectedly - the user's
> > input is not echoed to the screen as she types it.  A patch is attached
> > which solves the problem.
> 
> Thanks, this is a long-standing and known feature of Hugs' interact
> implementation, so before possibly bringing it into line with what
> Haskell 98 tells us how `interact' ought to behave regarding echoing
> of input,  it would be prudent to first check whether anyone depends
> on the current behaviour. In particular, are there 'important' resources
> (e.g., textbooks and tutorials) based around Hugs98 that depend on
> the current non-echoing behaviour?

Bird (2nd ed) makes use of the non-echoing interact, and describes
another, programmed, solution to restore echoing, all on a single page
(pp.230).

Regards,
    Malcolm