src/Symantic/Semantics/Reader.hs

   1 -- | This module provides the 'Reader' semantic
   2 -- which enables to change the syntax combinators using an environment.
   3 module Symantic.Semantics.Reader where
   4
   5 import Data.Function (const, (.))
   6
   7 import Symantic.Syntaxes.Classes hiding (const, (.))
   8 import Symantic.Syntaxes.Derive
   9
  10 -- * Type 'Reader'
  11
  12 -- | An intermediate semantic exposing an environment.
  13 newtype Reader r sem a = Reader {unReader :: r -> sem a}
  14
  15 type instance Derived (Reader r sem) = sem
  16 instance LiftDerived (Reader r sem) where
  17   liftDerived = Reader . const
  18 instance LiftDerived1 (Reader r sem) where
  19   liftDerived1 f a = Reader (f . unReader a)
  20 instance LiftDerived2 (Reader r sem) where
  21   liftDerived2 f a b = Reader (\r -> f (unReader a r) (unReader b r))
  22 instance LiftDerived3 (Reader r sem) where
  23   liftDerived3 f a b c = Reader (\r -> f (unReader a r) (unReader b r) (unReader c r))
  24 instance LiftDerived4 (Reader r sem) where
  25   liftDerived4 f a b c d = Reader (\r -> f (unReader a r) (unReader b r) (unReader c r) (unReader d r))
  26
  27 instance Abstractable sem => Abstractable (Reader r sem) where
  28   lam f = Reader (\r -> lam ((`unReader` r) . f . liftDerived))
  29 instance Abstractable1 sem => Abstractable1 (Reader r sem) where
  30   lam1 f = Reader (\r -> lam1 ((`unReader` r) . f . liftDerived))
  31 instance Instantiable sem => Instantiable (Reader r sem)
  32 instance Unabstractable sem => Unabstractable (Reader r sem)
  33 instance Varable sem => Varable (Reader r sem)
  34 instance Anythingable sem => Anythingable (Reader r sem)
  35 instance Constantable c sem => Constantable c (Reader r sem)
  36 instance Eitherable sem => Eitherable (Reader r sem)
  37 instance Equalable sem => Equalable (Reader r sem)
  38 instance IfThenElseable sem => IfThenElseable (Reader r sem)
  39
  40 -- Using 'Inferable' with a specific @a@ and keeping @sem@ polymorphic
  41 -- is more usual; hence commenting this instance that would overlap.
  42 -- instance Inferable a sem => Inferable a (Reader r sem)
  43 instance Listable sem => Listable (Reader r sem)
  44 instance Maybeable sem => Maybeable (Reader r sem)
  45 instance IsoFunctor sem => IsoFunctor (Reader r sem)
  46 instance (ProductFunctor sem, IsoFunctor sem) => ProductFunctor (Reader r sem)
  47 instance (SumFunctor sem, IsoFunctor sem) => SumFunctor (Reader r sem)
  48 instance AlternativeFunctor sem => AlternativeFunctor (Reader r sem)
  49 instance Dicurryable sem => Dicurryable (Reader r sem)
  50 instance Emptyable sem => Emptyable (Reader r sem)
  51 instance Semigroupable sem => Semigroupable (Reader r sem)
  52 instance Optionable sem => Optionable (Reader r sem)
  53 instance Repeatable sem => Repeatable (Reader r sem)
  54
  55 -- instance Permutable sem => Permutable (Reader r sem)
  56 instance Voidable sem => Voidable (Reader r sem)
  57 instance Substractable sem => Substractable (Reader r sem)