RWST.dcl

   1 definition module RWST
   2
   3 from Control.Applicative import class Applicative
   4 from Control.Monad import class Monad
   5 from Data.Void import :: Void
   6 from Data.Functor import class Functor
   7 from Data.Functor.Identity import :: Identity
   8 from Data.Monoid import class Monoid, class Semigroup
   9
  10 // The RWS monad
  11 :: RWS r w s a :== RWST r w s Identity a
  12
  13 rws :: (r -> s -> (a, s, w)) -> RWS r w s a
  14 runRWS :: (RWS r w s a) r s -> (a, s, w)
  15 evalRWS :: (RWS r w s a) r s -> (a, w)
  16 execRWS :: (RWS r w s a) r s -> (s, w)
  17 mapRWS :: ((a, s, w) -> (b, s, w`)) (RWS r w s a) -> RWS r w` s b
  18 withRWS :: (r` s -> (r, s)) (RWS r w s a) -> RWS r` w s a
  19
  20 // The RWST monad transformer
  21 :: RWST r w s m a = RWST (r s -> m (a, s, w))
  22
  23 instance Functor (RWST r w s m) | Monad m & Monoid w
  24 instance Applicative (RWST r w s m) | Monad m & Monoid w
  25 instance Monad (RWST r w s m) | Monad m & Monoid w
  26
  27 runRWST :: (RWST r w s m a) r s -> m (a, s, w)
  28 evalRWST :: (RWST r w s m a) r s -> m (a, w) | Monad m
  29 execRWST :: (RWST r w s m a) r s -> m (s, w) | Monad m
  30 mapRWST :: ((m (a, s, w)) -> n (b, s, w`)) (RWST r w s m a) -> RWST r w` s n b
  31 withRWST :: (r` -> s -> (r, s)) (RWST r w s m a) -> RWST r` w s m a
  32
  33 // Reader operations
  34 ask :: RWST r w s m r | Monoid w & Monad m
  35 local :: (r -> r) (RWST r w s m a) -> RWST r w s m a | Monoid w & Monad m
  36 asks :: (r -> a) -> RWST r w s m a | Monoid w & Monad m
  37
  38 // Writer operations
  39 tell :: w -> RWST r w s m Void | Monoid w & Monad m
  40 listen :: (RWST r w s m a) -> RWST r w s m (a, w) | Monoid w & Monad m
  41 pass :: (RWST r w s m (a, w -> w)) -> RWST r w s m a | Monoid w & Monad m
  42 listens :: (w -> b) (RWST r w s m a) -> RWST r w s m (a, b)| Monoid w & Monad m
  43 censor :: (w -> w) (RWST r w s m a) -> RWST r w s m a | Monoid w & Monad m
  44
  45 // State operations
  46 get :: RWST r w s m s | Monoid w & Monad m
  47 put :: s -> RWST r w s m Void | Monoid w & Monad m
  48 modify :: (s -> s) -> RWST r w s m Void | Monoid w & Monad m
  49 gets :: (s -> a) -> RWST r w s m a | Monoid w & Monad m
  50
  51 // Lifting other operations
  52 liftCallCC :: ((((a,s,w) -> m (b,s,w)) -> m (a,s,w)) -> m (a,s,w)) ((a -> RWST r w s m b) -> RWST r w s m a) -> RWST r w s m a | Monoid w
  53 liftCallCC` :: ((((a,s,w) -> m (b,s,w)) -> m (a,s,w)) -> m (a,s,w)) ((a -> RWST r w s m b) -> RWST r w s m a) -> RWST r w s m a | Monoid w
  54 liftCatch :: ((m (a,s,w)) (e -> m (a,s,w)) -> m (a,s,w)) (RWST l w s m a) (e -> RWST l w s m a) -> RWST l w s m a