On Sat, Jan 18, 2014 at 6:57 PM, Carter Schonwald
Point being, I think your pointing to an idea other people are (also) interested in exploring for ghc, and that there's some interesting subltelties to it.
I was actually kind of hoping someone would point out some of those subtleties. I figure there must be some since I don't know of any compiler other than the common lisp ones that implements something like this. Another thing that it could be useful for is that when declaring data it's sometimes convenient to declare data structures separately and then stitch them together, e.g. xs = makeXs [("name1", a), ("name2", b), ...] -- makeXs uses list order to infer things ys = makeYs [('x', ..., "name2"), ('y', ..., "name1")] -- same for makeYs things = do (c, ..., name) <- ys let x = fromMaybe (error "ack") $ lookup name xs return $ Thing name c x ... Not only would compile time evaluation eliminate some startup overhead, it could enforce at compile time that the names match up, along with other invariants in literal data, such as uniqueness, or that your keymap doesn't have any collisions, or whatever.