On Fri, Oct 2, 2015 at 9:37 PM, martin <martin.drautzburg@web.de> wrote:

I guess I am after values which become more and more defined in the course of computation.

One way to simulate incremental binding is by extending with multiple Maybes:

Nothing would mean 'no reservation'

Just Nothing -> 'reservation but unassigned room'

Just (Room 123) -> 'reservation with assigned room'

The type used is Maybe (Maybe Room).

-- Kim-Ee