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variable / @typed/fx/Sink

filterMapLoopEffect

Threads state through an effectful success transition and optionally forwards its value.

Package version
2.0.0-beta.7
Category
Stateful delivery
Since
1.0.0

Import

import { filterMapLoopEffect } from "@typed/fx/Sink";

Signatures

export declare const filterMapLoopEffect: {
    <B, A, E2, R2, C>(seed: B, f: (acc: B, a: A) => Effect.Effect<readonly [
        Option.Option<C>,
        B
    ], E2, R2>): <E, R>(sink: Sink<C, E, R>) => Sink<A, E | E2, R | R2>;
    <A, E, R, B, R2, C>(sink: Sink<C, E, R>, seed: B, f: (acc: B, a: A) => Effect.Effect<readonly [
        Option.Option<C>,
        B
    ], E, R2>): Sink<A, E, R | R2>;
};

Why

One transition can perform service-backed work, update state, and decide whether the consumer should observe a value.

Ownership and lifetime

Callback invocation constructs a transition Effect from the seed visible at that moment. The adapter does not serialize those Effects: overlapping callbacks can read the same seed, and successful transitions commit in completion order. Some then invokes the wrapped sink once, None not at all, and failure invokes its failure callback without committing. The sink instance retains its seed across producer runs; construct a new one to reset it.

Examples

import { Effect, Option } from "effect"
import * as Sink from "@typed/fx/Sink"
const target = Sink.make(Effect.logError, Effect.log)
const sink = Sink.filterMapLoopEffect(target, 0, (count, n: number) => Effect.succeed([Option.some(n), count + 1] as const))

Other public imports

These import paths expose the same declaration. Each page retains its own public name and signature.

Source