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variable / @typed/fx/Fx

drain

Runs an Fx stream to completion, discarding all values. Useful when the side effects of the stream are all that matter.

Package version
2.0.0-beta.13
Category
Running effects
Since
1.0.0

Follow one execution

Run the source and discard successful payloads; the Effect completes only after source return.

Fx timelinedrain(source)drain
Operatordrain(source)
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.

Running the Effect owns one source subscription until completion, failure, or interruption. It allocates no collection and adds no per-value effect. Source failures and services remain visible.

Source implementation · Learn the surrounding model

Compare all Fx timelines →

Import

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

Signatures

export declare const drain: <A, E, R>(fx: Fx<A, E, R>) => Effect<void, E, R>;

Why

Some producers perform all useful work in acquisition, effects, or finalization and need execution without retaining their emitted values.

Ownership and lifetime

Running the Effect owns one source subscription until completion, failure, or interruption. It allocates no collection and adds no per-value effect. Source failures and services remain visible.

Examples

import { drain, fromIterable } from "@typed/fx/Fx"

const program = drain(fromIterable([1, 2, 3]))

Other public imports

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

Source