Follow one execution
Each predicate Effect takes one turn in this serialized source. Its failure is forwarded rather than treated as false. The predicate still runs after the gate opens.
skipWhileEffectTick 0. Input: banner; Predicate: start.
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 gate belongs to one run, while predicate invocation inherits the producer’s ordering and concurrency. Predicate failure is delivered even after the gate opened; services remain required and interruption cancels whichever callback Effects the producer attached to the run.
Import
import { skipWhileEffect } from "@typed/fx/Fx";Signatures
export declare const skipWhileEffect: {
<A, E2, R2>(predicate: (a: A) => Effect.Effect<boolean, E2, R2>): <E, R>(fx: Fx<A, E, R>) => Fx<A, E | E2, R | R2>;
<A, E, R, E2, R2>(fx: Fx<A, E, R>, predicate: (a: A) => Effect.Effect<boolean, E2, R2>): Fx<A, E | E2, R | R2>;
};Why
skipWhileEffect performs Effectful prefix decisions. The gate opens at the first false result,
but the implementation eagerly constructs and runs predicate(a) before reading that gate, so
the predicate still runs for every later input even though those values are always forwarded.
Ownership and lifetime
The gate belongs to one run, while predicate invocation inherits the producer’s ordering and concurrency. Predicate failure is delivered even after the gate opened; services remain required and interruption cancels whichever callback Effects the producer attached to the run.
Examples
import { Effect, Ref } from "effect"
import { Fx } from "@typed/fx"
const program = Effect.gen(function* () {
const checks = yield* Ref.make(0)
const values = yield* Fx.collectAll(
Fx.fromIterable([2, 3]).pipe(
Fx.skipWhileEffect((n) => Ref.update(checks, (count) => count + 1).pipe(Effect.as(n < 2)))
)
)
return { values, checks: yield* Ref.get(checks) } // { values: [2, 3], checks: 2 }
})Other public imports
These import paths expose the same declaration. Each page retains its own public name and signature.