8 Jun
2007
8 Jun
'07
5:49 p.m.
On Fri, Jun 08, 2007 at 05:23:23PM +0200, Phlex wrote:
But i don't seem to find a way to get out of this DbIndex type to actually work on the enclosed index.
for instance, this doesn't work: liftDbIndex (DbIndex index) fun = DbIndex (fun index)
The compiler probably can't infer higher-ranker types, so you have to write you type signature explicitly. Try: liftDbIndex :: Index_ i2 a2 k2 => (forall a1 k1 i1. Index_ i1 a1 k1 => i1 -> i2) -> DbIndex -> DbIndex Best regards Tomek