| Copyright | (c) Ivan Perez and Manuel Baerenz 2016 |
|---|---|
| License | BSD3 |
| Maintainer | ivan.perez@keera.co.uk |
| Safe Haskell | Safe-Inferred |
| Language | Haskell2010 |
Data.MonadicStreamFunction.Util
Description
Useful auxiliary functions and definitions.
Synopsis
- type MStream m a = MSF m () a
- type MSink m a = MSF m a ()
- mapMaybeS :: Monad m => MSF m a b -> MSF m (Maybe a) (Maybe b)
- withSideEffect :: Monad m => (a -> m b) -> MSF m a a
- withSideEffect_ :: Monad m => m b -> MSF m a a
- iPre :: Monad m => a -> MSF m a a
- iPost :: Monad m => b -> MSF m a b -> MSF m a b
- next :: Monad m => b -> MSF m a b -> MSF m a b
- fifo :: Monad m => MSF m [a] (Maybe a)
- count :: (Num n, Monad m) => MSF m a n
- sumS :: (VectorSpace v s, Monad m) => MSF m v v
- sumFrom :: (VectorSpace v s, Monad m) => v -> MSF m v v
- mappendS :: (Monoid n, Monad m) => MSF m n n
- mappendFrom :: (Monoid n, Monad m) => n -> MSF m n n
- accumulateWith :: Monad m => (a -> s -> s) -> s -> MSF m a s
- mealy :: Monad m => (a -> s -> (b, s)) -> s -> MSF m a b
- unfold :: Monad m => (a -> (b, a)) -> a -> MSF m () b
- repeatedly :: Monad m => (a -> a) -> a -> MSF m () a
- trace :: Show a => String -> MSF IO a a
- traceWith :: (Monad m, Show a) => (String -> m ()) -> String -> MSF m a a
- traceWhen :: (Monad m, Show a) => (a -> Bool) -> (String -> m ()) -> String -> MSF m a a
- pauseOn :: Show a => (a -> Bool) -> String -> MSF IO a a
Streams and sinks
type MStream m a = MSF m () a Source #
A stream is an MSF that produces outputs, while ignoring the input. It
can obtain the values from a monadic context.
type MSink m a = MSF m a () Source #
A sink is an MSF that consumes inputs, while producing no output. It
can consume the values with side effects.
Analogues of map and fmap
Adding side effects
withSideEffect :: Monad m => (a -> m b) -> MSF m a a Source #
Applies a function to produce an additional side effect and passes the input unchanged.
withSideEffect_ :: Monad m => m b -> MSF m a a Source #
Produces an additional side effect and passes the input unchanged.
Delays
iPost :: Monad m => b -> MSF m a b -> MSF m a b Source #
Preprends a fixed output to an MSF. The first input is completely
ignored.
next :: Monad m => b -> MSF m a b -> MSF m a b Source #
Preprends a fixed output to an MSF, shifting the output.
fifo :: Monad m => MSF m [a] (Maybe a) Source #
Buffers and returns the elements in FIFO order, returning Nothing
whenever the buffer is empty.
Folding
Folding for VectorSpace instances
count :: (Num n, Monad m) => MSF m a n Source #
Count the number of simulation steps. Produces 1, 2, 3,...
sumFrom :: (VectorSpace v s, Monad m) => v -> MSF m v v Source #
Sums the inputs, starting from an initial vector.
Folding for monoids
mappendFrom :: (Monoid n, Monad m) => n -> MSF m n n Source #
Accumulate the inputs, starting from an initial monoid value.
Generic folding / accumulation
accumulateWith :: Monad m => (a -> s -> s) -> s -> MSF m a s Source #
Applies a function to the input and an accumulator, outputting the updated
accumulator. Equal to f s0 -> feedback s0 $ arr (uncurry f >>> dup).
mealy :: Monad m => (a -> s -> (b, s)) -> s -> MSF m a b Source #
Applies a transfer function to the input and an accumulator, returning the updated accumulator and output.
Unfolding
unfold :: Monad m => (a -> (b, a)) -> a -> MSF m () b Source #
Generate outputs using a step-wise generation function and an initial value.
repeatedly :: Monad m => (a -> a) -> a -> MSF m () a Source #
Generate outputs using a step-wise generation function and an initial
value. Version of unfold in which the output and the new accumulator are
the same. Should be equal to f a -> unfold (f >>> dup) a.
Debugging
trace :: Show a => String -> MSF IO a a Source #
Outputs every input sample, with a given message prefix.
traceWith :: (Monad m, Show a) => (String -> m ()) -> String -> MSF m a a Source #
Outputs every input sample, with a given message prefix, using an auxiliary printing function.