Safe Haskell | None |
---|---|

Language | Haskell98 |

## Synopsis

- data family Dynamic t :: * -> *
- current :: Reflex t => Dynamic t a -> Behavior t a
- updated :: Reflex t => Dynamic t a -> Event t a
- holdDyn :: MonadHold t m => a -> Event t a -> m (Dynamic t a)
- mapDynM :: forall t m a b. (Reflex t, MonadHold t m) => (forall m'. MonadSample t m' => a -> m' b) -> Dynamic t a -> m (Dynamic t b)
- forDynM :: forall t m a b. (Reflex t, MonadHold t m) => Dynamic t a -> (forall m'. MonadSample t m' => a -> m' b) -> m (Dynamic t b)
- constDyn :: Reflex t => a -> Dynamic t a
- count :: (Reflex t, MonadHold t m, MonadFix m, Num b) => Event t a -> m (Dynamic t b)
- toggle :: (Reflex t, MonadHold t m, MonadFix m) => Bool -> Event t a -> m (Dynamic t Bool)
- switchDyn :: forall t a. Reflex t => Dynamic t (Event t a) -> Event t a
- switchPromptlyDyn :: forall t a. Reflex t => Dynamic t (Event t a) -> Event t a
- tagPromptlyDyn :: Reflex t => Dynamic t a -> Event t b -> Event t a
- attachPromptlyDyn :: Reflex t => Dynamic t a -> Event t b -> Event t (a, b)
- attachPromptlyDynWith :: Reflex t => (a -> b -> c) -> Dynamic t a -> Event t b -> Event t c
- attachPromptlyDynWithMaybe :: Reflex t => (a -> b -> Maybe c) -> Dynamic t a -> Event t b -> Event t c
- maybeDyn :: forall t a m. (Reflex t, MonadFix m, MonadHold t m) => Dynamic t (Maybe a) -> m (Dynamic t (Maybe (Dynamic t a)))
- eitherDyn :: forall t a b m. (Reflex t, MonadFix m, MonadHold t m) => Dynamic t (Either a b) -> m (Dynamic t (Either (Dynamic t a) (Dynamic t b)))
- factorDyn :: forall t m k v. (Reflex t, MonadHold t m, GEq k) => Dynamic t (DSum k v) -> m (Dynamic t (DSum k (Compose (Dynamic t) v)))
- scanDyn :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b) -> (a -> b -> b) -> Dynamic t a -> m (Dynamic t b)
- scanDynMaybe :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b) -> (a -> b -> Maybe b) -> Dynamic t a -> m (Dynamic t b)
- holdUniqDyn :: (Reflex t, MonadHold t m, MonadFix m, Eq a) => Dynamic t a -> m (Dynamic t a)
- holdUniqDynBy :: (Reflex t, MonadHold t m, MonadFix m) => (a -> a -> Bool) -> Dynamic t a -> m (Dynamic t a)
- improvingMaybe :: (Reflex t, MonadHold t m, MonadFix m) => Dynamic t (Maybe a) -> m (Dynamic t (Maybe a))
- foldDyn :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> b) -> b -> Event t a -> m (Dynamic t b)
- foldDynM :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> PushM t b) -> b -> Event t a -> m (Dynamic t b)
- foldDynMaybe :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> Maybe b) -> b -> Event t a -> m (Dynamic t b)
- foldDynMaybeM :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> PushM t (Maybe b)) -> b -> Event t a -> m (Dynamic t b)
- joinDynThroughMap :: forall t k a. (Reflex t, Ord k) => Dynamic t (Map k (Dynamic t a)) -> Dynamic t (Map k a)
- traceDyn :: (Reflex t, Show a) => String -> Dynamic t a -> Dynamic t a
- traceDynWith :: Reflex t => (a -> String) -> Dynamic t a -> Dynamic t a
- splitDynPure :: Reflex t => Dynamic t (a, b) -> (Dynamic t a, Dynamic t b)
- distributeMapOverDynPure :: (Reflex t, Ord k) => Map k (Dynamic t v) -> Dynamic t (Map k v)
- distributeDMapOverDynPure :: forall t k. (Reflex t, GCompare k) => DMap k (Dynamic t) -> Dynamic t (DMap k Identity)
- distributeListOverDynPure :: Reflex t => [Dynamic t v] -> Dynamic t [v]
- data Demux t k
- demux :: (Reflex t, Ord k) => Dynamic t k -> Demux t k
- demuxed :: (Reflex t, Eq k) => Demux t k -> k -> Dynamic t Bool
- data HList (l :: [*]) where
- data FHList f l where
- collectDynPure :: (RebuildSortedHList (HListElems b), IsHList a, IsHList b, AllAreFunctors (Dynamic t) (HListElems b), Reflex t, HListElems a ~ FunctorList (Dynamic t) (HListElems b)) => a -> Dynamic t b
- class RebuildSortedHList l where
- rebuildSortedFHList :: [DSum (HListPtr l) f] -> FHList f l
- rebuildSortedHList :: [DSum (HListPtr l) Identity] -> HList l

- class IsHList a where
- type HListElems a :: [*]
- toHList :: a -> HList (HListElems a)
- fromHList :: HList (HListElems a) -> a

- class AllAreFunctors (f :: a -> *) (l :: [a]) where
- type FunctorList f l :: [*]
- toFHList :: HList (FunctorList f l) -> FHList f l
- fromFHList :: FHList f l -> HList (FunctorList f l)

- data HListPtr l a where
- distributeFHListOverDynPure :: (Reflex t, RebuildSortedHList l) => FHList (Dynamic t) l -> Dynamic t (HList l)
- unsafeDynamic :: Reflex t => Behavior t a -> Event t a -> Dynamic t a

# Basics

data family Dynamic t :: * -> * Source #

A container for a value that can change over time and allows
notifications on changes. Basically a combination of a `Behavior`

and an
`Event`

, with a rule that the `Behavior`

will change if and only if the
`Event`

fires.

## Instances

mapDynM :: forall t m a b. (Reflex t, MonadHold t m) => (forall m'. MonadSample t m' => a -> m' b) -> Dynamic t a -> m (Dynamic t b) Source #

Map a sampling function over a `Dynamic`

.

forDynM :: forall t m a b. (Reflex t, MonadHold t m) => Dynamic t a -> (forall m'. MonadSample t m' => a -> m' b) -> m (Dynamic t b) Source #

Flipped version of `mapDynM`

switchDyn :: forall t a. Reflex t => Dynamic t (Event t a) -> Event t a Source #

Switches to the new `Event`

whenever it receives one. Only the old event is
considered the moment a new one is switched in; the output event will fire at
that moment if only if the old event does.

Prefer this to `switchPromptlyDyn`

where possible. The lack of doing double
work when the outer and (new) inner fires means this imposes fewer "timing
requirements" and thus is far more easy to use without introducing fresh
failure cases. `switchDyn`

is also more performant.

switchPromptlyDyn :: forall t a. Reflex t => Dynamic t (Event t a) -> Event t a Source #

Switches to the new `Event`

whenever it receives one. Switching occurs
**before** the inner `Event`

fires - so if the `Dynamic`

changes and both the
old and new inner Events fire simultaneously, the output will fire with the
value of the **new** `Event`

.

Prefer `switchDyn`

to this where possible. The timing requirements that
switching before imposes are likely to bring down your app unless you are
very careful. `switchDyn`

is also more performant.

tagPromptlyDyn :: Reflex t => Dynamic t a -> Event t b -> Event t a Source #

Replace the value of the `Event`

with the current value of the `Dynamic`

each time the `Event`

occurs.

Note:

differs from *tagPromptlyDyn d e*

in the case that *tag (current d) e*

is firing
at the same time that *e*

is changing. With *d*

, the *tagPromptlyDyn d e***new** value of

will replace the value of *d*

, whereas with *e*

, the *tag (current d) e***old** value
will be used, since the `Behavior`

won't be updated until the end of the frame.
Additionally, this means that the output `Event`

may not be used to directly change
the input `Dynamic`

, because that would mean its value depends on itself. **When creating**
**cyclic data flows, generally **

*tag (current d) e*is preferred.

attachPromptlyDyn :: Reflex t => Dynamic t a -> Event t b -> Event t (a, b) Source #

Attach the current value of the `Dynamic`

to the value of the
`Event`

each time it occurs.

Note:

is not the same as *attachPromptlyDyn d*

. See *attach (current d)*`tagPromptlyDyn`

for details.

attachPromptlyDynWith :: Reflex t => (a -> b -> c) -> Dynamic t a -> Event t b -> Event t c Source #

Combine the current value of the `Dynamic`

with the value of the
`Event`

each time it occurs.

Note:

is not the same as *attachPromptlyDynWith f d*

. See *attachWith f (current d)*`tagPromptlyDyn`

for details.

attachPromptlyDynWithMaybe :: Reflex t => (a -> b -> Maybe c) -> Dynamic t a -> Event t b -> Event t c Source #

Create a new `Event`

by combining the value at each occurrence with the
current value of the `Dynamic`

value and possibly filtering if the combining
function returns `Nothing`

.

Note:

is not the same as *attachPromptlyDynWithMaybe f d*

. See *attachWithMaybe f (current d)*`tagPromptlyDyn`

for details.

maybeDyn :: forall t a m. (Reflex t, MonadFix m, MonadHold t m) => Dynamic t (Maybe a) -> m (Dynamic t (Maybe (Dynamic t a))) Source #

Factor a

into a *Dynamic t (Maybe a)*

,
such that the outer *Dynamic t (Maybe (Dynamic t a))*`Dynamic`

is updated only when the Maybe's constructor
chages from `Nothing`

to `Just`

or vice-versa. Whenever the constructor
becomes `Just`

, an inner `Dynamic`

will be provided, whose value will track
the `a`

inside the `Just`

; when the constructor becomes `Nothing`

, the
existing inner `Dynamic`

will become constant, and will not change when the
outer constructor changes back to `Nothing`

.

eitherDyn :: forall t a b m. (Reflex t, MonadFix m, MonadHold t m) => Dynamic t (Either a b) -> m (Dynamic t (Either (Dynamic t a) (Dynamic t b))) Source #

factorDyn :: forall t m k v. (Reflex t, MonadHold t m, GEq k) => Dynamic t (DSum k v) -> m (Dynamic t (DSum k (Compose (Dynamic t) v))) Source #

scanDyn :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b) -> (a -> b -> b) -> Dynamic t a -> m (Dynamic t b) Source #

scanDynMaybe :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b) -> (a -> b -> Maybe b) -> Dynamic t a -> m (Dynamic t b) Source #

Like `scanDyn`

, but the the accumulator function may decline to update the
result `Dynamic'`

s value.

holdUniqDyn :: (Reflex t, MonadHold t m, MonadFix m, Eq a) => Dynamic t a -> m (Dynamic t a) Source #

Create a new `Dynamic`

that only signals changes if the values actually
changed.

holdUniqDynBy :: (Reflex t, MonadHold t m, MonadFix m) => (a -> a -> Bool) -> Dynamic t a -> m (Dynamic t a) Source #

improvingMaybe :: (Reflex t, MonadHold t m, MonadFix m) => Dynamic t (Maybe a) -> m (Dynamic t (Maybe a)) Source #

that can only update from *Dynamic Maybe*

to *Nothing*

or *Just*

to *Just*

(i.e., cannot revert to *Just*

)*Nothing*

foldDyn :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> b) -> b -> Event t a -> m (Dynamic t b) Source #

foldDynM :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> PushM t b) -> b -> Event t a -> m (Dynamic t b) Source #

foldDynMaybe :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> Maybe b) -> b -> Event t a -> m (Dynamic t b) Source #

Create a `Dynamic`

using the provided initial value and change it each time
the provided `Event`

occurs, using a function to combine the old value with
the `Event'`

s value. If the function returns `Nothing`

, the value is not
changed; this is distinct from returning `Just`

the old value, since the
`Dynamic'`

s `updated`

`Event`

will fire in the `Just`

case, and will not fire
in the `Nothing`

case.

foldDynMaybeM :: (Reflex t, MonadHold t m, MonadFix m) => (a -> b -> PushM t (Maybe b)) -> b -> Event t a -> m (Dynamic t b) Source #

Like `foldDynMaybe`

, but the combining function is a `PushM`

action, so it
can `sample`

existing `Behaviors`

and `hold`

new ones.

joinDynThroughMap :: forall t k a. (Reflex t, Ord k) => Dynamic t (Map k (Dynamic t a)) -> Dynamic t (Map k a) Source #

traceDyn :: (Reflex t, Show a) => String -> Dynamic t a -> Dynamic t a Source #

Print the value of the `Dynamic`

when it is first read and on each
subsequent change that is observed (as `traceEvent`

), prefixed with the
provided string. This should *only* be used for debugging.

Note: Just like Debug.Trace.trace, the value will only be shown if something else in the system is depending on it.

traceDynWith :: Reflex t => (a -> String) -> Dynamic t a -> Dynamic t a Source #

Print the result of applying the provided function to the value
of the `Dynamic`

when it is first read and on each subsequent change
that is observed (as `traceEvent`

). This should *only* be used for
debugging.

Note: Just like Debug.Trace.trace, the value will only be shown if something else in the system is depending on it.

distributeMapOverDynPure :: (Reflex t, Ord k) => Map k (Dynamic t v) -> Dynamic t (Map k v) Source #

distributeDMapOverDynPure :: forall t k. (Reflex t, GCompare k) => DMap k (Dynamic t) -> Dynamic t (DMap k Identity) Source #

This function converts a `DMap`

whose elements are `Dynamic`

s into a
`Dynamic`

`DMap`

. Its implementation is more efficient than doing the same
through the use of multiple uses of `zipDynWith`

or `Applicative`

operators.

distributeListOverDynPure :: Reflex t => [Dynamic t v] -> Dynamic t [v] Source #

Deprecated: Use `distributeListOverDyn`

instead

Convert a list with `Dynamic`

elements into a `Dynamic`

of a list with
non-`Dynamic`

elements, preserving the order of the elements.

Represents a time changing value together with an `EventSelector`

that can
efficiently detect when the underlying `Dynamic`

has a particular value.
This is useful for representing data like the current selection of a long
list.

Semantically,

demuxed (demux d) k === fmap (== k) d

However, when getDemuxed is used multiple times, the complexity is only
*O(log(n))*, rather than *O(n)* for fmap.

# Miscellaneous

data HList (l :: [*]) where Source #

A heterogeneous list whose type and length are fixed statically. This is
reproduced from the `HList`

package due to integration issues, and because
very little other functionality from that library is needed.

collectDynPure :: (RebuildSortedHList (HListElems b), IsHList a, IsHList b, AllAreFunctors (Dynamic t) (HListElems b), Reflex t, HListElems a ~ FunctorList (Dynamic t) (HListElems b)) => a -> Dynamic t b Source #

class RebuildSortedHList l where Source #

This class allows `HList`

s and `FHlist`

s to be built from regular lists;
they must be contiguous and sorted.

rebuildSortedFHList :: [DSum (HListPtr l) f] -> FHList f l Source #

rebuildSortedHList :: [DSum (HListPtr l) Identity] -> HList l Source #

## Instances

RebuildSortedHList ([] :: [Type]) Source # | |

Defined in Reflex.Dynamic | |

RebuildSortedHList t => RebuildSortedHList (h ': t) Source # | |

Defined in Reflex.Dynamic |

class IsHList a where Source #

Poor man's `Generic`

s for product types only.

type HListElems a :: [*] Source #

toHList :: a -> HList (HListElems a) Source #

fromHList :: HList (HListElems a) -> a Source #

## Instances

IsHList (a, b) Source # | |

Defined in Reflex.Dynamic type HListElems (a, b) :: [Type] Source # toHList :: (a, b) -> HList (HListElems (a, b)) Source # fromHList :: HList (HListElems (a, b)) -> (a, b) Source # | |

IsHList (a, b, c, d) Source # | |

Defined in Reflex.Dynamic type HListElems (a, b, c, d) :: [Type] Source # toHList :: (a, b, c, d) -> HList (HListElems (a, b, c, d)) Source # fromHList :: HList (HListElems (a, b, c, d)) -> (a, b, c, d) Source # | |

IsHList (a, b, c, d, e, f) Source # | |

Defined in Reflex.Dynamic type HListElems (a, b, c, d, e, f) :: [Type] Source # toHList :: (a, b, c, d, e, f) -> HList (HListElems (a, b, c, d, e, f)) Source # fromHList :: HList (HListElems (a, b, c, d, e, f)) -> (a, b, c, d, e, f) Source # |

class AllAreFunctors (f :: a -> *) (l :: [a]) where Source #

Indicates that all elements in a type-level list are applications of the same functor.

type FunctorList f l :: [*] Source #

toFHList :: HList (FunctorList f l) -> FHList f l Source #

fromFHList :: FHList f l -> HList (FunctorList f l) Source #

## Instances

AllAreFunctors (f :: a -> Type) ([] :: [a]) Source # | |

Defined in Reflex.Dynamic type FunctorList f [] :: [Type] Source # toFHList :: HList (FunctorList f []) -> FHList f [] Source # fromFHList :: FHList f [] -> HList (FunctorList f []) Source # | |

AllAreFunctors f t => AllAreFunctors (f :: a -> Type) (h ': t :: [a]) Source # | |

Defined in Reflex.Dynamic type FunctorList f (h ': t) :: [Type] Source # toFHList :: HList (FunctorList f (h ': t)) -> FHList f (h ': t) Source # fromFHList :: FHList f (h ': t) -> HList (FunctorList f (h ': t)) Source # |

data HListPtr l a where Source #

A typed index into a typed heterogeneous list.

## Instances

GCompare (HListPtr l :: k -> Type) Source # | |

GEq (HListPtr l :: k -> Type) Source # | |

Eq (HListPtr l a2) Source # | |

Ord (HListPtr l a2) Source # | |

Defined in Reflex.Dynamic compare :: HListPtr l a2 -> HListPtr l a2 -> Ordering # (<) :: HListPtr l a2 -> HListPtr l a2 -> Bool # (<=) :: HListPtr l a2 -> HListPtr l a2 -> Bool # (>) :: HListPtr l a2 -> HListPtr l a2 -> Bool # (>=) :: HListPtr l a2 -> HListPtr l a2 -> Bool # |

distributeFHListOverDynPure :: (Reflex t, RebuildSortedHList l) => FHList (Dynamic t) l -> Dynamic t (HList l) Source #