Limiting resources on a per-function basis?

Hi all, I would really like to be able to set resource limits on a per-function basis. I am envisioning something like: limit :: l -> (a -> b) -> (a -> Maybe b) limit lim fn = ... which would convert a function so that it returns Nothing if a limit (on stack, heap, time, etc.) is exceeded during evaluation of that function. Is there any hope of being able to do this within the existing GHC libraries? If not, is it even possible to determine after-the-fact how much stack or heap space a function evaluation required? Thanks, Jeff Newbern -- Jeff Newbern Nomaware, Inc.