Haskell report typo (bad law for readsPrec)

[Wolfgang Lux]

Sorry, it hit the wrong button so the following didn't go to the list.

> "Simon Peyton-Jones" wrote
> 
> > 
> > | Another simple alternative is to weaken the the equation by 
> > | replacing the variable r by the empty string: [Alternative B:]
> > | 
> > | ...
> > |    should be the case that
> > | 
> > |      fst (head (readsPrec d (showsPrec d x ""))) == x
> > 
> > Yes, I like this alternative too.  I'll implement it.
> 
> Why not require
> 
>   readsPrec d (showPrec d x "") == [(x,"")]
> 
> in this case? At least it should be
> 
>   head (readsPrec d x "") == (x,"")
> 
> Regards
> Wolfgang
> 
--
Wolfgang Lux				  Phone: +49-251-83-38263
Institut fuer Wirtschaftinformatik	    FAX: +49-251-83-38259
Universitaet Muenster		      Email: wlux@uni-muenster.de