Copyright	(c) Target RWE 2023
License	BSD3
Maintainer	bbrown@targetrwe.com ljackman@targetrwe.com dpritchard@targetrwe.com
Safe Haskell	Safe-Inferred
Language	Haskell2010

EventDataTheory.Utilities

Description

Synopsis

newtype Predicate a = Predicate {
- getPredicate :: a -> Bool
}
containsTag :: Ord t => [t] -> Predicate (Event t m a)
findOccurrenceOfEvent :: Filterable f => (f (Event t m a) -> Maybe (Event t m a)) -> Predicate (Event t m a) -> f (Event t m a) -> Maybe (Event t m a)
firstOccurrenceOfTag :: (Witherable f, Ord t) => [t] -> f (Event t m a) -> Maybe (Event t m a)
lastOccurrenceOfTag :: (Witherable f, Ord t) => [t] -> f (Event t m a) -> Maybe (Event t m a)
splitByTags :: (Filterable f, Ord t) => [t] -> [t] -> f (Event t m a) -> (f (Event t m a), f (Event t m a))
filterEvents :: Filterable f => Predicate (Event t m a) -> f (Event t m a) -> f (Event t m a)
tallyEvents :: Witherable f => Predicate (Event t m a) -> f (Event t m a) -> Int

Documentation

newtype Predicate a #

Constructors

Predicate
Fields getPredicate :: a -> Bool

Instances

Instances details

Contravariant Predicate	A `Predicate` is a `Contravariant` `Functor`, because `contramap` can apply its function argument to the input of the predicate. Without newtypes `contramap f` equals precomposing with `f` (= `(. f)`). contramap :: (a' -> a) -> (Predicate a -> Predicate a') contramap f (Predicate g) = Predicate (g . f)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a' -> a) -> Predicate a -> Predicate a' # (>$) :: b -> Predicate b -> Predicate a #
Monoid (Predicate a)	`mempty` on predicates always returns `True`. Without newtypes this equals `pure True`. mempty :: Predicate a mempty = _ -> True
Instance details Defined in Data.Functor.Contravariant Methods mempty :: Predicate a # mappend :: Predicate a -> Predicate a -> Predicate a # mconcat :: [Predicate a] -> Predicate a #
Semigroup (Predicate a)	`(<>)` on predicates uses logical conjunction `(&&)` on the results. Without newtypes this equals `liftA2 (&&)`. (<>) :: Predicate a -> Predicate a -> Predicate a Predicate pred <> Predicate pred' = Predicate a -> pred a && pred' a
Instance details Defined in Data.Functor.Contravariant Methods (<>) :: Predicate a -> Predicate a -> Predicate a # sconcat :: NonEmpty (Predicate a) -> Predicate a # stimes :: Integral b => b -> Predicate a -> Predicate a #
ToDhall x => FromDhall (Predicate x)
Instance details Defined in Dhall.Marshal.Decode Methods autoWith :: InputNormalizer -> Decoder (Predicate x)

containsTag :: Ord t => [t] -> Predicate (Event t m a) Source #

Creates a predicate to check that an Event contains any of a given list of tags.

findOccurrenceOfEvent Source #

Arguments

:: Filterable f
=> (f (Event t m a) -> Maybe (Event t m a))	function used to select a single event after the container is filtered
-> Predicate (Event t m a)	predicate by which to filter
-> f (Event t m a)	a container of events
-> Maybe (Event t m a)

Filter a container of Events to a single Maybe Event, based on a provided function, with the provided tag set.

For example, see firstOccurrenceOfTag and lastOccurrenceOfTag.

firstOccurrenceOfTag :: (Witherable f, Ord t) => [t] -> f (Event t m a) -> Maybe (Event t m a) Source #

Finds the *first* occurrence of an Event with at least one of the tags if one exists. Assumes the input events are appropriately sorted.

lastOccurrenceOfTag :: (Witherable f, Ord t) => [t] -> f (Event t m a) -> Maybe (Event t m a) Source #

Finds the *last* occurrence of an Event with at least one of the tags if one exists. Assumes the input events list are appropriately sorted.

splitByTags :: (Filterable f, Ord t) => [t] -> [t] -> f (Event t m a) -> (f (Event t m a), f (Event t m a)) Source #

Split a container of Events into a pair of Events. The first element contains events have any of the tags in the first argument, similarly for the second element.

Note that one or both of the resulting containers may be empty.

filterEvents :: Filterable f => Predicate (Event t m a) -> f (Event t m a) -> f (Event t m a) Source #

Filter a container of events by a predicate.

tallyEvents :: Witherable f => Predicate (Event t m a) -> f (Event t m a) -> Int Source #

Tally the number of events in a container satisfying the given predicate.