src/Symantic/Reader.hs

   1 module Symantic.Reader where
   2
   3 import Data.Function ((.), const)
   4
   5 import Symantic.Classes hiding (const, (.))
   6 import Symantic.Derive
   7
   8 -- * Type 'Reader'
   9 -- | An intermediate interpreter exposing an environment.
  10 newtype Reader r repr a = Reader { unReader :: r -> repr a }
  11
  12 type instance Derived (Reader r repr) = repr
  13 instance LiftDerived (Reader r repr) where
  14   liftDerived = Reader . const
  15 instance LiftDerived1 (Reader r repr) where
  16   liftDerived1 f a = Reader (f . unReader a)
  17 instance LiftDerived2 (Reader r repr) where
  18   liftDerived2 f a b = Reader (\r -> f (unReader a r) (unReader b r))
  19 instance LiftDerived3 (Reader r repr) where
  20   liftDerived3 f a b c = Reader (\r -> f (unReader a r) (unReader b r) (unReader c r))
  21 instance LiftDerived4 (Reader r repr) where
  22   liftDerived4 f a b c d = Reader (\r -> f (unReader a r) (unReader b r) (unReader c r) (unReader d r))
  23
  24 instance Abstractable repr => Abstractable (Reader r repr) where
  25   lam f = Reader (\r -> lam ((`unReader` r) . f . liftDerived))
  26   lam1 f = Reader (\r -> lam1 ((`unReader` r) . f . liftDerived))
  27 instance Functionable repr => Functionable (Reader r repr)
  28 instance Anythingable repr => Anythingable (Reader r repr)
  29 instance Constantable c repr => Constantable c (Reader r repr)
  30 instance Eitherable repr => Eitherable (Reader r repr)
  31 instance Equalable repr => Equalable (Reader r repr)
  32 instance IfThenElseable repr => IfThenElseable (Reader r repr)
  33 -- Using 'Inferable' with a specific @a@ and keeping @repr@ polymorphic
  34 -- is more usual; hence commenting this instance that would overlap.
  35 --instance Inferable a repr => Inferable a (Reader r repr)
  36 instance Listable repr => Listable (Reader r repr)
  37 instance Maybeable repr => Maybeable (Reader r repr)
  38 instance IsoFunctor repr => IsoFunctor (Reader r repr)
  39 instance (ProductFunctor repr, IsoFunctor repr) => ProductFunctor (Reader r repr)
  40 instance (SumFunctor repr, IsoFunctor repr) => SumFunctor (Reader r repr)
  41 instance AlternativeFunctor repr => AlternativeFunctor (Reader r repr)
  42 instance Dicurryable repr => Dicurryable (Reader r repr)
  43 instance Emptyable repr => Emptyable (Reader r repr)
  44 instance Semigroupable repr => Semigroupable (Reader r repr)
  45 instance Optionable repr => Optionable (Reader r repr)
  46 instance Repeatable repr => Repeatable (Reader r repr)
  47 -- instance Permutable repr => Permutable (Reader r repr)
  48 instance Routable repr => Routable (Reader r repr)
  49 instance Voidable repr => Voidable (Reader r repr)
  50 instance Substractable repr => Substractable (Reader r repr)