scalaz/scalaz — pull request #204 by seanparsons (2012-11-30 17:41:39+00:00)
Title: Make Function0 map/bind lazy in their implementation.

Previously if you (flat)mapped a Function0 it would execute it at the point of mapping and create the new Function0 with that value. This brings it in line with the other FunctionN variations by mapping at call time.

I'm somewhat of two minds about this change as it does make sense to do the existing behaviour if the Function0 can be guaranteed to be pure however.