uds/param/ASDS/Source.icl

   1 implementation module ASDS.Source
   2
   3 import Data.Func
   4 import Data.Functor
   5 import Control.Monad
   6 import ASDS
   7
   8 rwpair :: (sdsr m p r w) (sdsw m p r w) -> RWPair sdsr sdsw m p r w | pure m
   9 rwpair l r = RWPair l r (pure ())
  10
  11 source :: (p -> m r) (p w -> m ()) -> Source m p r w | pure m
  12 source read write = rwpair (ReadSource read) (WriteSource write)
  13
  14 instance read ReadSource
  15 where
  16         read (ReadSource read) p = Read <$> read p
  17
  18 instance write WriteSource
  19 where
  20         write (WriteSource write) p w = Written <$> write p w
  21
  22 instance read (RWPair sdsr sdsw) | read sdsr
  23 where
  24         read (RWPair s w _) p = read s p >>= \v->case v of
  25                 Reading s = pure $ Reading (rwpair s w)
  26                 Read r = pure $ Read r
  27
  28 instance write (RWPair sdsr sdsw) | write sdsw
  29 where
  30         write (RWPair r s _) p w = write s p w >>= \v->case v of
  31                 Writing s = pure $ Writing $ rwpair r s
  32                 Written _ = pure $ Written ()
  33
  34 constShare :: a -> ReadSource m p a b | pure m
  35 constShare a = ReadSource \_->pure a
  36
  37 nullShare :: WriteSource m p a b | pure m
  38 nullShare = WriteSource \_ _->pure ()