Re: Comments on current TypeHoles implementation

* Roman Cheplyaka [2012-10-05 10:22:23+0300]

* Simon Peyton-Jones [2012-10-05 07:14:36+0000]

...

| Sounds cool. I would also expect that if you have several occurences of | the same unbound identifier, then it gets a unified type.

I thought about this, but I think not. Consider

f x1 = _y g x2 = _y

Do you want _y and _y to be unified, so that f and g are no longer polymorphic? I think not. Any more than the "_" holes we have now are unified.

Do you mean polymorphism in their argument? Why would it go away?

I would expect the functions to get types `a -> c` and `b -> c` respectively, and `c` to be reported as the type of the hole.

Ah, I see. Since `c` is universally quantified, it means different things for f and g. Good point. Roman