Copyright | (c) Ivan Perez and Manuel Baerenz 2016 |
---|---|

License | BSD3 |

Maintainer | ivan.perez@keera.co.uk |

Safe Haskell | Safe-Inferred |

Language | Haskell2010 |

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.