Comments on current TypeHoles implementation

Roman Cheplyaka roma at
Fri Oct 5 09:22:23 CEST 2012

* Simon Peyton-Jones <simonpj at> [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.


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