defaults

[Malcolm Wallace]

Simon Marlow <simonmar at microsoft.com> wrote:

> >> If so, then I offer a counter example:
> >>     toRational pi
> >
> > If these two points are valid, then I think the slight loss
> > of backward compatibility is acceptable?
> 
> I spotted the problem because it
> looks (to me) like the current Haskell 98 rule is designed
> specifically to handle cases like this.

I agree that having to write
    toRational (pi::Double)
is somewhat ugly.

> Would you mind updating the wiki page?  I don't think it's too clear
> on the need for constraint simplification before applying your
> defaulting rules either.

I have added your counter example to the wiki.  But I'm not sure how to
make the need for constraint simplification clearer.  3 out of the 7
sentences in the proposal describe it, and 3 out of the 5 examples
mention its role.  What do you think is missing?

Regards,
    Malcolm