Safe Haskell | None |
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- data Evt a = Evt {}
- type Bam a = a -> SE ()
- boolToEvt :: BoolSig -> Evt Unit
- evtToBool :: Evt a -> SE BoolSig
- sigToEvt :: Sig -> Evt Unit
- stepper :: Tuple a => a -> Evt a -> SE a
- filterE :: (a -> BoolD) -> Evt a -> Evt a
- filterSE :: (a -> SE BoolD) -> Evt a -> Evt a
- accumSE :: Tuple s => s -> (a -> s -> SE (b, s)) -> Evt a -> Evt b
- accumE :: Tuple s => s -> (a -> s -> (b, s)) -> Evt a -> Evt b
- filterAccumE :: Tuple s => s -> (a -> s -> (BoolD, b, s)) -> Evt a -> Evt b
- filterAccumSE :: Tuple s => s -> (a -> s -> SE (BoolD, b, s)) -> Evt a -> Evt b
- type family Snap a :: *
- snapshot :: (Tuple a, Tuple (Snap a)) => (Snap a -> b -> c) -> a -> Evt b -> Evt c
- snaps :: Sig -> Evt D
- sync :: (Default a, Tuple a) => D -> Evt a -> Evt a
- syncBpm :: (Default a, Tuple a) => D -> Evt a -> Evt a
- metroE :: Sig -> Evt Unit
- changedE :: [Sig] -> Evt Unit
- triggerE :: Sig -> Sig -> Sig -> Evt Unit
- cycleE :: (Tuple a, Arg a) => [a] -> Evt b -> Evt a
- iterateE :: Tuple a => a -> (a -> a) -> Evt b -> Evt a
- repeatE :: Tuple a => a -> Evt b -> Evt a
- appendE :: Tuple a => a -> (a -> a -> a) -> Evt a -> Evt a
- mappendE :: (Monoid a, Tuple a) => Evt a -> Evt a
- partitionE :: (a -> BoolD) -> Evt a -> (Evt a, Evt a)
- splitToggle :: Evt D -> (Evt D, Evt D)
- oneOf :: (Tuple a, Arg a) => [a] -> Evt b -> Evt a
- freqOf :: (Tuple a, Arg a) => Rnds a -> Evt b -> Evt a
- freqAccum :: (Tuple s, Tuple (b, s), Arg (b, s)) => s -> (a -> s -> Rnds (b, s)) -> Evt a -> Evt b
- randDs :: Evt b -> Evt D
- randInts :: (D, D) -> Evt b -> Evt D
- randSkip :: D -> Evt a -> Evt a
- randSkipBy :: (a -> D) -> Evt a -> Evt a
- range :: (D, D) -> Evt b -> Evt D
- listAt :: (Tuple a, Arg a) => [a] -> Evt D -> Evt a
- every :: (Tuple a, Arg a) => Int -> [Int] -> Evt a -> Evt a
- masked :: (Tuple a, Arg a) => [D] -> Evt a -> Evt a

# Documentation

data Evt a

A stream of events. We can convert a stream of events to
the procedure with the function `runEvt`

. It waits for events
and invokes the given procedure when the event happens.

# Core functions

evtToBool :: Evt a -> SE BoolSig

Converts an event to boolean signal. It forgets everything about the event values. Signal equals to one when an event happens and zero otherwise.

accumSE :: Tuple s => s -> (a -> s -> SE (b, s)) -> Evt a -> Evt b

Accumulator for events with side effects.

filterAccumE :: Tuple s => s -> (a -> s -> (BoolD, b, s)) -> Evt a -> Evt b

Accumulator with filtering. It can skip the events from the event stream. If the third element of the triple equals to 1 then we should include the event in the resulting stream. If the element equals to 0 we skip the event.

filterAccumSE :: Tuple s => s -> (a -> s -> SE (BoolD, b, s)) -> Evt a -> Evt b

Accumulator for events with side effects and filtering. Event triggers only if the first element in the tripplet is true.

type family Snap a :: *

A snapshot of the signal. It converts a type of the signal to the type of the value in the given moment. Instances:

type instance Snap D = D type instance Snap Str = Str type instance Snap Tab = Tab type instance Snap Sig = D type instance Snap (a, b) = (Snap a, Snap b) type instance Snap (a, b, c) = (Snap a, Snap b, Snap c) type instance Snap (a, b, c, d) = (Snap a, Snap b, Snap c, Snap d) type instance Snap (a, b, c, d, e) = (Snap a, Snap b, Snap c, Snap d, Snap e) type instance Snap (a, b, c, d, e, f) = (Snap a, Snap b, Snap c, Snap d, Snap e, Snap f)

snapshot :: (Tuple a, Tuple (Snap a)) => (Snap a -> b -> c) -> a -> Evt b -> Evt c

Get values of some signal at the given events.

Constructs an event stream that contains values from the given signal. Events happens only when the signal changes.

sync :: (Default a, Tuple a) => D -> Evt a -> Evt a

Executes actions synchronized with global tempo (in Hz).

runEvtSync tempoCps evt proc

syncBpm :: (Default a, Tuple a) => D -> Evt a -> Evt aSource

the sync function but time is measured in beats per minute.

# Opcodes

# Higher-level event functions

cycleE :: (Tuple a, Arg a) => [a] -> Evt b -> Evt aSource

Constructs an event stream that contains an infinite repetition values from the given list. When an event happens this function takes the next value from the list, if there is no values left it starts from the beggining of the list.

iterateE :: Tuple a => a -> (a -> a) -> Evt b -> Evt aSource

When something happens on the given event stream resulting event stream contains an application of some unary function to the given initial value. So the event stream contains the values:

[s0, f s0, f (f s0), f (f (f s0)), ...]

repeatE :: Tuple a => a -> Evt b -> Evt aSource

Substitutes all values in the input stream with the given constant value.

appendE :: Tuple a => a -> (a -> a -> a) -> Evt a -> Evt aSource

Accumulates a values from the given event stream with binary function. It's a variant of the fold for event streams.

appendE z f evt

When value `a`

happens with `evt`

, the resulting event stream contains
a value (z `f`

a) and in the next time `z`

equals to this value.

partitionE :: (a -> BoolD) -> Evt a -> (Evt a, Evt a)Source

Splits event stream on two streams with predicate.

splitToggle :: Evt D -> (Evt D, Evt D)Source

Splits a toggle event stream on on-events and off-events.

oneOf :: (Tuple a, Arg a) => [a] -> Evt b -> Evt aSource

Constructs an event stream that contains values from the given list which are taken in the random order.

freqOf :: (Tuple a, Arg a) => Rnds a -> Evt b -> Evt aSource

Constructs an event stream that contains values from the given list which are taken in the random order. In the list we specify not only values but the frequencies of occurrence. Sum of the frequencies should be equal to one.

freqAccum :: (Tuple s, Tuple (b, s), Arg (b, s)) => s -> (a -> s -> Rnds (b, s)) -> Evt a -> Evt bSource

This function combines the functions `accumE`

and
`freqOf`

. We transform the values of the event stream
with stateful function that produce not just values but the list of values
with frequencies of occurrence. We apply this function to the current state
and the value and then at random pick one of the values.

randInts :: (D, D) -> Evt b -> Evt DSource

An event stream of the integers taken from the given diapason.

randSkip :: D -> Evt a -> Evt aSource

Skips elements at random.

randSkip prob

where `prob`

is probability of includinng the element in the output stream.

randSkipBy :: (a -> D) -> Evt a -> Evt aSource

Skips elements at random.

randSkip probFun

It behaves just like `randSkip`

, but probability depends on the value.

listAt :: (Tuple a, Arg a) => [a] -> Evt D -> Evt aSource

Turns an event of indices to the event of the values from the list. A value is taken with index.

every :: (Tuple a, Arg a) => Int -> [Int] -> Evt a -> Evt aSource

Specialization of the function `masked`

.

every n [a, b, c, ..] evt

constructs a mask that skips first `n`

elements and then produces
an event and skips next (a - 1) events, then produces an event and
skips next (b - 1) events and so on. It's useful for construction of
the percussive beats. For example

every 0 [2] (metroE 2)

triggers an event on the odd beats. With this function we can create a complex patterns of cyclic events.