uds/ASDS/Lens.dcl

   1 definition module ASDS.Lens
   2
   3 from ASDS import class read, class write, :: LensWrite, :: LensRead
   4
   5 from StdOverloaded import class <
   6 from StdClass import class Eq
   7 from Control.Monad import class Monad
   8 from Control.Monad.Fail import class MonadFail
   9 from Control.Applicative import class Applicative, class <*>, class pure
  10 from Data.Functor import class Functor
  11 from Data.Map import :: Map
  12
  13 //* Apply a lens to a share
  14 :: Lens sds m p r w = E.p1 r1 w1: Lens (LensOpts sds m p1 r1 w1 p r w) & TC r1 & TC w1 & TC p1
  15 :: LensOpts sds m p1 r1 w1 p r w =
  16         { param  :: p -> p1
  17         , mapr   :: LensRead m p r r1
  18         , mapw   :: LensWrite m p w r1 w1
  19         , lens   :: sds m p1 r1 w1
  20         }
  21 lens :: (p -> p1) (LensRead m p r r1) (LensWrite m p w r1 w1) (sds m p1 r1 w1) -> Lens sds m p r w | TC r1 & TC w1 & TC p1
  22
  23 instance read (Lens sds) | read sds
  24 instance write (Lens sds) | read sds & write sds
  25
  26 //* Map a function to the value read
  27 mapRead :: (r -> m r`) (sds m p r w) -> Lens sds m p r` w | TC r` & TC r & TC w & TC p & Monad m
  28 (>?@) infixl 6
  29 (>?@) :== mapRead
  30
  31 //* Map a function to the value written.
  32 mapWrite :: (w` r -> m (? w)) (sds m p r w) -> Lens sds m p r w` | TC r & TC w & TC w` & TC p & Monad m
  33 (>!@) infixl 6
  34 (>!@) :== mapWrite
  35
  36 //* Translate the parameter space
  37 translate :: (p -> ps) (sds m ps r w) -> Lens sds m p r w | TC r & TC w & TC p & TC ps & Monad m
  38
  39 //* focus a parameter: @type :: p (sds m p r w) -> (sds m p` r w)
  40 focus p :== translate \_->p
  41
  42 //* Deserialize from a dynamic store
  43 fromDynStore :: (sds m p Dynamic Dynamic) -> Lens sds m p r w | TC r & TC w & TC p & MonadFail m
  44
  45 //* Serialize to a dynamic store
  46 toDynStore :: (sds m p r w) -> Lens sds m p Dynamic Dynamic | TC r & TC w & TC p & MonadFail m
  47
  48 //* Focus on a single element in a list
  49 indexedStore :: (sds m p [a] [a]) -> Lens sds m (p, Int) a a | TC a & TC p & MonadFail m
  50
  51 //* Focus on a single element in an associative list
  52 assocStore :: (sds m p [(k, v)] [(k, v)]) -> Lens sds m (p, k) v v | TC v & TC k & Eq k & TC p & MonadFail m
  53
  54 //* Focus on a value in a map
  55 keyedStore :: (sds m p (Map k v) (Map k v)) -> Lens sds m (p, k) v v | TC v & TC k & < k & TC p & MonadFail m