Halogen.Hooks.Types

data HookType

The kind of types used in Hooks; primitive Hooks already have this kind, and Hooks of your own should be foreign imported data types that are also types of this kind:

foreign import data UseX :: Hooks.HookType

newtype StateId state

A unique identifier for a state produced by useState, which can be passed to the state functions get, put, modify, and modify_ to get or modify the state.

This token should NOT be modified.

state /\ stateId <- useState 0

let
  handler = Hooks.modify_ stateId (_ + 10)

Constructors

• StateId (Tuple ComponentRef Int)

data ComponentRef

A unique reference for a component, which is used to track which component Hooks code is defined in to ensure that it isn't run in another component (this is unsafe, and doing so will throw an exception).

type ComponentTokens :: (Type -> Type) -> Row Type -> Type -> Typetype ComponentTokens q ps o = { outputToken :: OutputToken o, queryToken :: QueryToken q, slotToken :: SlotToken ps }

The set of tokens enabling queries, child slots, and output messages when running a Hook as a component. This set of tokens is provided by the Hooks.component function.

Hooks do not have a notion of parent / child relationships, and Halogen features like queries and outputs don't make sense in the context of Hooks. These tokens enable those features for Hooks which are being turned into components, while ensuring Hooks which are being nested are not able to access those features.

data QueryToken :: (Type -> Type) -> Typedata QueryToken (a :: Type -> Type)

A token which carries the type of queries supported by the component which is executing a Hook. Queries are specific to the parent-child component relationship, and so they are not tracked in Hook types.

This token is provided by the component function.

data SlotToken :: Row Type -> Typedata SlotToken (slots :: Row Type)

A token which carries the type of child slots supported by the component which is executing a Hook. Child slots are specific to the parent-child component relationship, and so they are not tracked in Hook types.

This token is provided by the component function.

data OutputToken output

A token which carries the type of outputs supported by the component which is executing a Hook. Output messages slots are specific to the parent-child component relationship, and so they are not tracked in Hook types.

This token is provided by the component function.

data MemoValues

An opaque type which signifies that a set of dependencies have been captured and can be used by Hooks like UseMemo and UseEffect.

This type is provided by the captures and capturesWith functions.