Helper types
ToNonPostableEvt<E>
NonPostableEvt<T> and StatefulReadonlyEvt<T> are interfaces implemented respectively by the classes Evt<T> and StatefulEvt<T>. They contains all the methods but the ones used to post events, namely: .post(), .postOnceHandled() and the .state setter for StatefulReadonlyEvt1
import { ToNonPostableEvt } from "evt";
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ToNonPostableEvt<Evt<T>> → NonPostableEvt<T>
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ToNonPostableEvt<SatefulEvt<T>> → StatefulReadonlyEvt<T>
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ToNonPostable<VoidEvt> → NonPostable<Void>
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ToNonPostable<NonpostableEvt<T>> → NonPostableEvt<T>
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ToNonPostableEvt<{
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evtText: Evt<string>;
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evtCount: StatefulEvt<number>;
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type: "FOO"
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}>
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→
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{
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evtText: NonPostableEvt<string>;
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evtCount: StatefulNonpostableEvt<number>;
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type: "FOO"
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}
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Example use of the
NonPostableEvt interface:1
import { Evt, NonPostableEvt } from "evt";
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const evtText= new Evt<string>();
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//Api to expose.
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export const api:{ evtText: NonPostableEvt<string>; } = { evtText };
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//evtText exposed by the api cannot be posted…
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api.evtText.post //<=== TS error
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api.evtText.postOnceMatched //<===== TS error
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//…but we can post internally.
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evtText.post("good");
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ToPostableEvt<E>
Invert of
ToNonPostableEvt1
import {
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ToPostableEvt,
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NonPostableEvt,
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StatefulReadonlyEvt
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} from "evt";
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ToPostableEvt<NonPostableEvt<T>> → Evt<T>
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ToPostableEvt<StatefulReadonlyEvt<T>> → StatefulEvt<T>
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ToPostable<NonPostable<void>> → VoidEvt
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ToPostable<Evt<T>> → Evt<T>
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ToPostableEvt<{
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evtText: NonPostableEvt<string>;
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evtCount: StatefulReadonlyEvt<number>;
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type: "FOO"
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}>
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→
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{
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evtText: Evt<string>;
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evtCount: StatefulEvt<number>;
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type: "FOO"
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}
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UnpackEvt<E>
Extract the type argument of an Evt
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import { UnpackEvt } from "evt";
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UnpackEvt<Evt<number>> → number
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UnpackEvt<StatefulEvt<number>> → number
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UnpackEvt<NonpostableEvt<number>> → number
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UnpackEvt<{
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evtText: Evt<string>;
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evtCount: StatefulEvt<number>;
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type: "FOO"
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}>
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→
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{
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evtText: string;
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evtCount: number;
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type: "FOO"
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}
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Example:
UnpackEvt is a helper type to infer the type argument of an Evt instance.
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import { Evt, UnpackEvt } from "evt";
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const evtHuman = new Evt<{
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name: string;
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age: number;
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gender: "MALE" | "FEMALE"
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}>();
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type Human = UnpackEvt<typeof evtHuman>;
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const human: Human = {
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"name": "bob",
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"age": 89,
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"gender": "MALE"
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};
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evtHuman.post(human);
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SwapEvtType<E, T>
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import { SwapEvtType } from "evt";
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SwapEvtType<Evt<string>, number> → Evt<number>
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SwapEvtType<SatefulEvt<string>, number> → SatefulEvt<number>
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SwapEvtType<Evt<number>, void> → VoidEvt
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SwapEvtType<StatefulEvt<number>, void> → VoidEvt
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FactorizeEvt<E>
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import { FactorizeEvt } from "evt";
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FactorizeEvt<Evt<string> | Evt<number>> → Evt<string | number>
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//...Work as well with StatefulEvt, NonPostable ect
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Last modified 2yr ago