[Haskell-cafe] Help using QuickCheck

[Benjamin Franksen]

On Friday 21 October 2005 21:45, Andrew Pimlott wrote:
> On Fri, Oct 21, 2005 at 09:09:41PM +0200, Benjamin Franksen wrote:
> > Many thanks! I wish I had remembered that I had this kind of
> > problem before: ghc reports two errors, of which the /second/ one
> > is the 'real' problem and the first one is just a by-product.
>
> The case in your original message is particularly annoying, but at
> least it only affects ghci.  I thought it had been fixed[1], but it
> is still present in 6.4.1, so perhaps it's waiting for 6.5?
>
> > This practically never
> > happens with C compilers which I (must, sadly) use every day and
> > thus I always tend to disregard all error messages but the first.
>
> I generally find that most of GHC's errors are real, ie they don't
> change much when I fix earlier errors.  (It seems to report only one
> error per function to achieve that?)  It's fun to work through the
> dozen reported mistakes, then compile again to see how many I
> actually fixed.

Yes, normally the error messages from ghc are very good and useful. It 
happens only rarely that some error message is completely opaque to me 
and then my brain auto-switches to "ignore everything but the first 
message" mode -- which works great in C but in Haskell sometimes leads 
me completely astray...

Ben