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variable / @typed/fx/Fx

skipWhile

Skips elements from an Fx while a predicate returns true. Emits from the first element for which the predicate returns false (including that element) and all following elements.

Package version
2.0.0-beta.7
Category
Selecting values
Since
1.0.0

Follow one execution

Skips elements from an Fx while a predicate returns true. Emits from the first element for which the predicate returns false (including that element) and all following elements.

Fx timelineskipWhile(isBanner)skipWhile
OperatorskipWhile(isBanner)
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.

One boolean gate is owned by each run and then discarded. No resource is acquired and source errors, services, and interruption are preserved.

Source implementation · Learn the surrounding model

Compare all Fx timelines →

Import

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

Signatures

export declare const skipWhile: {
    <A>(predicate: (a: A) => boolean): <E, R>(fx: Fx<A, E, R>) => Fx<A, E, R>;
    <A, E, R>(fx: Fx<A, E, R>, predicate: (a: A) => boolean): Fx<A, E, R>;
};

Why

skipWhile discards only the longest matching prefix. The first false value opens the gate and is emitted; later values are forwarded without re-running the predicate.

Ownership and lifetime

One boolean gate is owned by each run and then discarded. No resource is acquired and source errors, services, and interruption are preserved.

Examples

import { Fx } from "@typed/fx"
const values = Fx.fromIterable([1, 2, 1]).pipe(Fx.skipWhile((n) => n < 2))

Other public imports

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

Source