7 Mar
2006
7 Mar
'06
5:51 p.m.
John Meacham wrote:
On Thu, Mar 02, 2006 at 03:53:45AM -0000, Claus Reinke wrote:
the problem is that we have somehow conjured up an infinite type for Mul to recurse on without end! Normally, such infinite types are ruled out by occurs-checks (unless you are working with Prolog III;-), so someone forgot to do that here. why? where? how?
Polymorphic recursion allows the construction of infinite types if I understand what you mean.
No, that's different. An infinite type can't be written in (legal) Haskell. It's something like type T = [T] -- Ben