[Yhc] Running catch on the HughesPJ prettyprinter

Thorkil Naur naur at post11.tele.dk
Fri Jul 27 03:12:04 EDT 2007


Hello,

On Thursday 26 July 2007 23:38, Ian Lynagh wrote:
> On Mon, Jul 23, 2007 at 02:43:57PM +0200, Thorkil Naur wrote:
> > 
> > This is fixed by changing HughesPJ.hs as follows:
> > 
> > > 931c931
> > > <         lay1 k _ sl _ | k+sl `seq` False = undefined
> > > ---
> > > >         lay1 k _ sl _ | (k+sl) `seq` False = undefined
> > 
> > And this is, of course, rather interesting, since this type error (I 
cannot 
> > see it as anything else) is neither detected by Hugs nor GHC. But that is 
a 
> > matter for further work some other time.
> 
>     http://haskell.org/onlinereport/standard-prelude.html
> says
>     infixl 6  +, -
>     infixr 0  $, $!, `seq`
> 
> so this should already parse like that. Perhaps yhc/catch is missing an
> infix decl?

You are right, of course. There is now a Yhc issue that describes this problem 
(http://code.google.com/p/yhc/issues/detail?id=145).

> 
> 
> Thanks
> Ian
> 
> 

Thanks and best regards
Thorkil


More information about the Yhc mailing list