The Event type puts a certain amount of structure on temporally organized data, while being flexible in the details. An 'Event t m a' contains information about when something occurred (the 'Interval a') and what occurred (the 'Context m t'). The type parameters m, t, and a allow to specify the types for the Contexts model and tagSet and for the type of the Interval end points.

The Event type parameters are ordered from changing the least often to most often. A model tends to be shared across projects. For example, multiple projects use data from insurance claims, and thus share a single model. A project often defines its own tagSet, though tag sets can be shared across projects. Within a project, multiple Interval types may used. Data may be imported as 'Interval Day', but then modified to 'Interval Integer' based on some reference point.

The contents of a Context are explained in a separate section, but we give a couple examples of using events here.

The event function is a smart constructor for Event.

>>> :set -XOverloadedStrings
>>> import IntervalAlgebra ( beginerval )

>>> data SomeModel = A | B deriving (Eq, Ord, Show, Generic)
>>> 
>>> type MyEvent = Event T.Text SomeModel Integer
>>> let myEvent = event (beginerval 5 0) (context (packTagSet ["foo"]) A Nothing) :: MyEvent
>>> show myEvent
"MkEvent {(0, 5), MkContext {getTagSet = MkTagSet (fromList [MkTag \"foo\"]), getFacts = A, getSource = Nothing}}"

>>> hasAnyTag myEvent (["foo", "duck"] :: [T.Text])
True

>>> hasAllTags myEvent (["foo", "duck"] :: [T.Text])
False

>>> data NewModel = A T.Text | B Integer deriving (Eq, Ord, Show, Generic)
>>> data MyTagSet = Foo | Bar | Baz deriving (Eq, Ord, Show, Generic)
>>> 
>>> type NewEvent = Event MyTagSet NewModel Integer
>>> let newEvent = event (beginerval 5 0) (context (packTagSet [Foo, Bar]) (A "cool") Nothing) :: NewEvent
>>> show newEvent
"MkEvent {(0, 5), MkContext {getTagSet = MkTagSet (fromList [MkTag Foo,MkTag Bar]), getFacts = A \"cool\", getSource = Nothing}}"

>>> hasTag newEvent Foo
True

>>> hasTag newEvent Baz
False

A smart constructor for 'Event t m a's.

Unpack an Event from its constructor.

Get the Context of an Event.

A Source may be used to record the source of an event from a database. This data is sometimes useful for debugging. We generally discourage using Source information in defining features.

A Tag is simply a label for an Event.

TagSet t is a Set of 'Tag t's. TagSet inherit the monoidal properties of Set, by union.

A Context contains information about what ocurred during an Events interval. This information is carried in context's tagSet and/or facts. TagSet are set of tags that can be used to identify and filter events using the hasTag function or the related hasAnyTag and hasAllTags functions. The facts field contains data of type m. The m stands for model, meaning the scope and shape of facts relevant to a particular scientific line of work. For example, some studies using health care claims data may be sufficiently different in scope, semanitcs, and aims to warrant having a different collection of facts from, say, electronic medical records data. However, one could create a collection of facts that includes both claims and EHR data. By having a Context parametrized by the shape of a model, users are free to define the structure of their facts as needed.

A context also has a source field, possibly containing a Source, which carries information about the provenance of the data.

A Tag Interval is simply a synonym for an Interval paired with TagSet.

the facts of a Context.

the Source of Context

the TagSet of a Context

Smart constructor for a Context,

Constructor for TagSet.

Wrap value as a Tag

Unwrap a value from a Tag

Put a list of values into a set of tagSet.

Take a tag set to a list of values.

Test whether a type a contains a t.

Does an a have *any* of a list of Tags?

Does an a have *all* of a list of Tags?

A utility for adding tag sets to a TagSet from a list.

Lifts a Predicate of a component of an Event to a Predicate on an Event

Lifts a function @@ of a component of an Event to a function on an Event

Lifts a function f of a component of an Context to a function on an Context

Apply a two functions to a Context:

1. a function transforming the tagSet
2. a function transforming the facts

This function is simiilar in flavor to bimap. But Context is not a Bifunctor. The underlying type of TagSet is Set, which is not a Functor because of the Set Ord constraints.

Apply a function to each Tag within a TagSet set.

NOTE: TagSet are not a Functor. The underlying type of TagSet is Set, which is not a Functor due to the Set Ord constraints.

Turn the Source within a Context to Nothing.

Contains a subject identifier

The HasTag typeclass provides predicate functions for determining whether an a contains a tag.

This class is only used in this Core module for the purposes of having a single hasTag function that works on TagSet, Context, or Event data.

Provides a common interface to lift a Predicate e to a Predicate (Event t m a).

For example, if x is a Predicate on some 'Context m t', liftToEventPredicate x yields a Predicate (Event t m a), thus the predicate then also be applied to Events.

This class is only used in this Core module for the purposes of having a single liftToEventPredicate function that works on TagSet, Context, or Event data.

A synonym for a basic set of constraints frequently used with the Event type.

Constraint synonym for FromSON on an event's component types.

Constraint synonym for ToJSON on an event's component types.