On Wed, Feb 01, 2006 at 10:32:26AM -0000, Simon Marlow wrote:
On 31 January 2006 17:48, Andrew Pimlott wrote:
This indicates that the warning "wouldn't happen much" _when you want sharing_. But it would happen all the time when you don't want sharing, eg. in the case Malcolm Wallace just posted.
So you either add a type signature, or turn off the warning.
Right (provided you understand the warning). Though I don't think many people would turn off a default warning--it's just too much trouble. (I always add dummy definitions of coarbitrary to my Arbitrary instances, rather than figure out how to suppress the undefined method warning.) So in practice, I think most people would add a type signature.
What's the problem?
I've learned from this sub-thread that people oppose the M-R for at different reasons. Some dislike it on principle, or on aesthetic grounds, and they would be happy to add a type signature. But others think it would be useful to define polymorphic variables without a type signature, and they would not be happy to add one.
I suspect you're saying that you don't want a warning by default, and you don't want the langage to recommend that compilers issue a warning by default, right? If so, your objection is duly noted and I'll add the point to the wiki.
Cool. Andrew