¤ postProcessHigh, preProcessHigh, et al

Types

postProcessHigh :: SP a ho -> F hi a -> F hi ho
preProcessHigh :: F c ho -> SP hi c -> F hi ho
postProcessLow :: SP TCommand TCommand -> F hi ho -> F hi ho
preProcessLow :: F hi ho -> SP TEvent TEvent -> F hi ho
postMapHigh :: (a -> ho) -> F hi a -> F hi ho
preMapHigh :: F c ho -> (hi -> c) -> F hi ho
preMapLow :: F hi ho -> (TEvent -> TEvent) -> F hi ho
postMapLow :: (TCommand -> TCommand) -> F hi ho -> F hi ho
prepostMapHigh :: (hi -> b) -> (c -> ho) -> F b c -> F hi ho
prepostMapLow :: (TEvent -> TEvent) -> (TCommand -> TCommand) -> F hi ho -> F hi ho
>^^=< :: SP a b -> F e a -> F e b
>=^^< :: F c d -> SP e c -> F e d
>..=< :: SP TCommand TCommand -> F hi ho -> F hi ho
>=..< :: F hi ho -> SP TEvent TEvent -> F hi ho
>^=< :: (a -> b) -> F e a -> F e b
>=^< :: F c d -> (e -> c) -> F e d
>.=< :: (TCommand -> TCommand) -> F hi ho -> F hi ho
>=.< :: F hi ho -> (TEvent -> TEvent) -> F hi ho

Description

There are two sets of operators. As suggested by the type signatures, the ones with Map (or a single ^ or .) as part of their names take functions that operate on single stream elements.

The operators with Process (or double ^^ or ..) as part of their names take stream processors as arguments.

Example

 (*2) >^=< fud   -- doubles the (numeric) output from fud

Equalities

The following equalities hold (except that the tagging of low level messages will be different). The left hand sides are likely to be more efficient.

  sp  >^^=< fud  =  absF sp >==< fud
  fud >=^^< sp   =  fud     >==< absF sp

  f   >^=<  fud  =  mapF f  >==< fud
  fud >=^<  f    =  fud     >==< mapF f

See Also