test/Machine.hs

   1 {-# LANGUAGE DataKinds #-}
   2 {-# LANGUAGE ExistentialQuantification #-}
   3 {-# LANGUAGE FlexibleContexts #-}
   4 {-# LANGUAGE RankNTypes #-}
   5 {-# LANGUAGE TypeFamilies #-}
   6 module Machine where
   7
   8 import Data.Text (Text)
   9 import Data.Functor ((<$>))
  10
  11 import qualified Symantic.Parser as P
  12 import Grammar
  13
  14 -- | Existential type to gather machines
  15 -- returning different values in the same @('machines')@ list.
  16 data M = forall a. M (
  17   forall repr inp. inp ~ Text =>
  18   P.Machine (P.InputToken inp) repr =>
  19   repr inp '[] a
  20   )
  21
  22 machines :: [M]
  23 machines = (\(G g) -> M (P.machine g)) <$> grammars