7 Mar
2003
7 Mar
'03
11:02 a.m.
On Fri, 7 Mar 2003 07:47:09 -0800 (PST)
Hal Daume III
That said, "undecidable instances" sound very scary, but they're really not. You can google around for a conversation I had with SPJ about this a while back, but something being an und instance is a compile time property. That is, if compilation succeeds, you don't have anything to worry about and the worst that can happen at compilation time is that you'll hit the bottom of this stack.
Thanks, you've been clear, even I miss that in haskell98 one can't define subset properties between type classes... maybe because that would mean "subtyping"? Vincenzo