= WwLazy -- Argument is lazy as far as we know
MaybeAbsent -- (does not imply worker's existence [etc]).
-- If MaybeAbsent == True, then it is
- -- *definitely* lazy. (NB: Absence implies
+ -- *definitely* lazy. (NB: Absence implies
-- a worker...)
| WwStrict -- Argument is strict but that's all we know