Hi,
GHC's behaviour is consistent with the report, Hugs' isn't.
This issue came up on the haskell mailing list a couple of months ago,
see
http://www.dcs.gla.ac.uk/mail-www/haskell/threads#00270
for more info.
hth,
--Sigbjorn
David Barton writes:
> Consider the following (literate) program:
>
> > module Main where
> > import IO
>
> > main:: IO()
> > main = hSetBuffering stdin NoBuffering >>
> > interact trns
>
> > trns:: String -> String
> > trns [] = []
> > trns (c:cs) =
> > let str c = case c of
> > '1' -> "one\n"
> > '2' -> "two\n"
> > '3' -> "three\n"
> > _ -> "other\n"
> > in (str c) ++ (trns cs)
>
> This compiles under both Hugs and GHC appropriately (note that I added
> a blank "hSetBuffering" defintion to IO.hs for Hugs). When I run the
> program under Hugs and enter press the keys "1234" on the keyboard I
> get the following output:
>
> one
> two
> three
> other
>
> which is just what I expect. On the other hand, when I try it under
> GHC it compiles appropriately and I get the following output:
>
> 1one
> 2two
> 3three
> 4other
>
> i.e. the input is somehow echoed to stdout without my trying to do
> anything. Is this a Unix thing? If so, why didn't it happen under
> Hugs? Is it a GHC thing? Is it controllable? If so, how can I stop
> it?
>
> Any help gratefully appreciated.
>
> Dave Barton <*>
> [EMAIL PROTECTED] )0(
> http://www.intermetrics.com/~dlb
