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variable / @typed/fx/Fx

takeEffect

Takes the first n elements where n is produced by an Effect.

Package version
2.0.0-beta.13
Category
Selecting values
Since
1.0.0

Follow one execution

Resolve the bound Effect before subscribing; then apply the resolved prefix or window. Acquisition failure prevents source work.

Fx timelinetakeEffect(loadCount)takeEffect
OperatortakeEffect(loadCount)
Read this diagram

Follow each lane from left to right. Events stacked vertically share a tick; the green cursor marks the current time across every lane.

  • A value
    The text inside the pill is the emitted value.
  • Work starts
    The raised chevron starts an inner run (^ in the source).
  • The run returns
    The vertical bar ends this lane’s run.
  • A cause is delivered
    The exclamation mark belongs to this lane.
  • Work is interrupted
    The cross marks cancellation of this run.
  • Current time
    The line and diamond move together across all lanes.
  • Happening now
    A highlighted event is at the current tick.
  • Still ahead
    Muted, dashed values have not happened yet.
  • Time continues
    The lane’s arrow is not a return marker. An empty stretch can be quiet work that is still running.

Illustrated ticks start at 0. At 1×, one illustrated tick takes one second; captions specify real durations when timing matters. A cause or interruption belongs to its lane, and other work may continue. Scroll horizontally to inspect the rest of a long timeline.

The count Effect can fail, require services, or be interrupted; in those cases upstream never starts. After success, reaching the limit stops upstream work.

Source implementation · Learn the surrounding model

Compare all Fx timelines →

Import

import { takeEffect } from "@typed/fx/Fx";

Signatures

export declare const takeEffect: {
    <E2, R2>(count: Effect.Effect<number, E2, R2>): <A, E, R>(fx: Fx<A, E, R>) => Fx<A, E | E2, R | R2>;
    <A, E, R, E2, R2>(fx: Fx<A, E, R>, count: Effect.Effect<number, E2, R2>): Fx<A, E | E2, R | R2>;
};

Why

takeEffect obtains a dynamic bound once before subscribing, then applies ordinary take.

Ownership and lifetime

The count Effect can fail, require services, or be interrupted; in those cases upstream never starts. After success, reaching the limit stops upstream work.

Examples

import { Effect } from "effect"
import { Fx } from "@typed/fx"

const first = Fx.fromIterable([1, 2]).pipe(Fx.takeEffect(Effect.succeed(1)))

Other public imports

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

Source