Hello again,
On Tue, Mar 1, 2016 at 11:56 AM, Simon Peyton Jones
Don't forget AbsDmd too!
Yes, we're working on this too. Currently we're doing something analogous to what we're doing with StrDmd: data UseDmd = UCall Count UseDmd | UProd [ArgUse] | USum [(Tag, UseDmd)] | UHead | Used The big question deals with how to 'insert' a usage demand on an alternative of a case into a usage demand on the entire sum. The current thought is that you collect the usage demands on the fields of the constructor for the alternative you're analysing (let's say it's tag 1) and insert that into a USum where the usage demands on all the other constructors (all the tags except 1) is UHead. The rational behind using UHead is that the constructor itself is demanded at UHead by the case expression. Once you have one of these for every alternative, you lub them together appropriately, so anywhere you actually used a field would be represented in the final demand on the sum since UHead `lubUse` u = u
Do start a wiki page to explain all this.
Definitely. Cheers, Jose