Roman Leshchinskiy
Ah. I missed that. Then your best bet is probably
replicate n action = munstream v $ Fusion.Stream.Monadic.generateM n (const action) $ new n
It's uglier that it should be but vector simply doesn't define the right combinators for this at the moment.
I'm having trouble getting this to typecheck. I'll reread your "Recycle Your Arrays" paper; maybe then it will make more sense.
There are two things one would have to do. First, add a function to Generic.New which initialises a New from a Monadic.Stream and fusion rules for it. That's easy. The hard part is to generalise New to work with arbitrary monads: at the moment it is defined as:
data New a = New (forall mv s. MVector mv a => ST s (mv s a))
This is because its basic reason for existence is to be passed to Vector.new which then does a runST to produce an immutable vector. It is perhaps possible to make New more general but it's quite tricky. I'll think about it after the ICFP deadline
But the "m" I'm interested in happens to be ST. Sounds like it's still easy in principle, but not immediate. Is that right? Thanks, Chad