| > I'm hoping we don't get more deeply invested in the syntactic change | in GHC | > 7.6 that removed the possibility of symbolic type variables ("~>", | "*", "+", | > etc). I had a new job and wasn't paying attention when SPJ polled the | > community. From my perspective, the loss has much greater scope than | the | > gain for type level naturals. I'd like to keep the door open to the | > possibility of bringing back the old notation with the help of a | language | > pragma. It would take a few of us to draft a proposal addressing | details. | | I also miss these on a regular basis. I seem to remember that during | the proposal, there was a mention of reversing the situation, i.e. | having a prefix for type variable operators instead. Did anything ever | come of that? I'm very open to concrete suggestions about this. I want Haskell to allow you to express the thoughts in your head, as directly as possible. We could add a LANGUAGE pragma. Or, more radically, we could support both at once, like this: data (&&) a b where ...blah blah... f :: Int && Int -> Bool f = ... data T (&&) x = MkT (x && x) -- Shadows (&&) The idea is that (&&) can be declared as a top-level type constructor, but then *shadowed* by an explicit local binding in the 'data T' declaration. This is somewhat analogous to the situation with values: f = True g f = f::Char where we define f globally and then shadow it. The apparent difference is that the top-level (&&) is a type constructor, whereas the local (&&) is a type variable; and in the value world we *never* shadow data constructors. But the counter-argument might be that type variables (unlike term variables) really do behave like type constructors: they are rigid and don't match anything else. So I think the door stands open here, if anyone wants to drive the debate and push it through to a consensus. Simon