Copyright	(C) 2012 Edward Kmett Rúnar Bjarnason
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	provisional
Portability	Rank-N Types, MPTCs
Safe Haskell	Safe
Language	Haskell2010

Data.Machine.Plan

Contents

Plans

Description

Synopsis

Plans

type Plan k o a = forall m. PlanT k o m a Source #

A Plan k o a is a specification for a pure Machine, that reads inputs selected by k with types based on i, writes values of type o, and has intermediate results of type a.

A Plan k o a can be used as a PlanT k o m a for any Monad m.

It is perhaps easier to think of Plan in its un-cps'ed form, which would look like:

data Plan k o a
  = Done a
  | Yield o (Plan k o a)
  | forall z. Await (z -> Plan k o a) (k z) (Plan k o a)
  | Fail

runPlan :: PlanT k o Identity a -> (a -> r) -> (o -> r -> r) -> (forall z. (z -> r) -> k z -> r -> r) -> r -> r Source #

Deconstruct a Plan without reference to a Monad.

newtype PlanT k o m a Source #

You can construct a Plan (or PlanT), turning it into a Machine (or MachineT).

Constructors

PlanT
Fields runPlanT :: forall r. (a -> m r) -> (o -> m r -> m r) -> (forall z. (z -> m r) -> k z -> m r -> m r) -> m r -> m r

Instances

MonadState s m => MonadState s (PlanT k o m) Source #
Methods get :: PlanT k o m s # put :: s -> PlanT k o m () # state :: (s -> (a, s)) -> PlanT k o m a #
MonadReader e m => MonadReader e (PlanT k o m) Source #
Methods ask :: PlanT k o m e # local :: (e -> e) -> PlanT k o m a -> PlanT k o m a # reader :: (e -> a) -> PlanT k o m a #
MonadError e m => MonadError e (PlanT k o m) Source #
Methods throwError :: e -> PlanT k o m a # catchError :: PlanT k o m a -> (e -> PlanT k o m a) -> PlanT k o m a #
MonadWriter w m => MonadWriter w (PlanT k o m) Source #
Methods writer :: (a, w) -> PlanT k o m a # tell :: w -> PlanT k o m () # listen :: PlanT k o m a -> PlanT k o m (a, w) # pass :: PlanT k o m (a, w -> w) -> PlanT k o m a #
MonadTrans (PlanT k o) Source #
Methods lift :: Monad m => m a -> PlanT k o m a #
Monad (PlanT k o m) Source #
Methods (>>=) :: PlanT k o m a -> (a -> PlanT k o m b) -> PlanT k o m b # (>>) :: PlanT k o m a -> PlanT k o m b -> PlanT k o m b # return :: a -> PlanT k o m a # fail :: String -> PlanT k o m a #
Functor (PlanT k o m) Source #
Methods fmap :: (a -> b) -> PlanT k o m a -> PlanT k o m b # (<$) :: a -> PlanT k o m b -> PlanT k o m a #
MonadFail (PlanT k o m) Source #
Methods fail :: String -> PlanT k o m a #
Applicative (PlanT k o m) Source #
Methods pure :: a -> PlanT k o m a # (<>) :: PlanT k o m (a -> b) -> PlanT k o m a -> PlanT k o m b # (>) :: PlanT k o m a -> PlanT k o m b -> PlanT k o m b # (<*) :: PlanT k o m a -> PlanT k o m b -> PlanT k o m a #
MonadIO m => MonadIO (PlanT k o m) Source #
Methods liftIO :: IO a -> PlanT k o m a #
Alternative (PlanT k o m) Source #
Methods empty :: PlanT k o m a # (<\|>) :: PlanT k o m a -> PlanT k o m a -> PlanT k o m a # some :: PlanT k o m a -> PlanT k o m [a] # many :: PlanT k o m a -> PlanT k o m [a] #
MonadPlus (PlanT k o m) Source #
Methods mzero :: PlanT k o m a # mplus :: PlanT k o m a -> PlanT k o m a -> PlanT k o m a #

yield :: o -> Plan k o () Source #

Output a result.

maybeYield :: Maybe o -> Plan k o () Source #

Like yield, except stops if there is no value to yield.

await :: Category k => Plan (k i) o i Source #

Wait for input.

await = awaits id

stop :: Plan k o a Source #

stop = empty

awaits :: k i -> Plan k o i Source #

Wait for a particular input.

awaits L  :: Plan (T a b) o a
awaits R  :: Plan (T a b) o b
awaits id :: Plan (Is i) o i

exhaust :: Monad m => m (Maybe a) -> PlanT k a m () Source #

Run a monadic action repeatedly yielding its results, until it returns Nothing.