<S, In>(
initial: LazyArg<S>,
f: (s: S, input: NonEmptyReadonlyArray<In>) => S
): Sink<S, In>A sink that reduces its inputs using the provided function f starting from
the specified initial state.
reducing
Source effect/Sink.ts:137315 lines
export const const reduceArray: <S, In>(
initial: LazyArg<S>,
f: (s: S, input: NonEmptyReadonlyArray<In>) => S
) => Sink<S, In>
A sink that reduces its inputs using the provided function f starting from
the specified initial state.
reduceArray = <function (type parameter) S in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>S, function (type parameter) In in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>In>(
initial: LazyArg<S>initial: type LazyArg<A> = () => AA zero-argument function that produces a value when invoked.
When to use
Use to type a lazy value provider that should not run until called.
Example (Creating a lazy argument)
import { Function } from "effect"
const constNull: Function.LazyArg<null> = Function.constant(null)
LazyArg<function (type parameter) S in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>S>,
f: (
s: S,
input: NonEmptyReadonlyArray<In>
) => S
s: Ss: function (type parameter) S in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>S, input: NonEmptyReadonlyArray<In>(parameter) input: {
0: In;
length: number;
toString: () => string;
toLocaleString: { (): string; (locales: string | string[], options?: Intl.NumberFormatOptions & Intl.DateTimeFormatOptions): string };
concat: { (...items: Array<ConcatArray<In>>): Array<In>; (...items: Array<In | ConcatArray<In>>): Array<In> };
join: (separator?: string) => string;
slice: (start?: number, end?: number) => Array<In>;
indexOf: (searchElement: In, fromIndex?: number) => number;
lastIndexOf: (searchElement: In, fromIndex?: number) => number;
every: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): this is readonly S[]; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): boolean };
some: (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any) => boolean;
forEach: (callbackfn: (value: In, index: number, array: ReadonlyArray<In>) => void, thisArg?: any) => void;
map: (callbackfn: (value: In, index: number, array: ReadonlyArray<In>) => U, thisArg?: any) => Array<U>;
filter: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): Array<S>; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): Array<In> };
reduce: { (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In): In; (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In, initialValue: In): I…;
reduceRight: { (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In): In; (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In, initialValue: In): I…;
find: { (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => value is S, thisArg?: any): S | undefined; (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => unknown, thisArg?: any): In | undefined };
findIndex: (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => unknown, thisArg?: any) => number;
entries: () => ArrayIterator<[number, In]>;
keys: () => ArrayIterator<number>;
values: () => ArrayIterator<In>;
includes: (searchElement: In, fromIndex?: number) => boolean;
flatMap: (callback: (this: This, value: In, index: number, array: Array<In>) => U | ReadonlyArray<U>, thisArg?: This | undefined) => Array<U>;
flat: (this: A, depth?: D | undefined) => Array<FlatArray<A, D>>;
at: (index: number) => In | undefined;
findLast: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): S | undefined; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): In | undefined };
findLastIndex: (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any) => number;
toReversed: () => Array<In>;
toSorted: (compareFn?: ((a: In, b: In) => number) | undefined) => Array<In>;
toSpliced: { (start: number, deleteCount: number, ...items: Array<In>): Array<In>; (start: number, deleteCount?: number): Array<In> };
with: (index: number, value: In) => Array<In>;
}
type NonEmptyReadonlyArray<A> = readonly [A, ...A[]]A readonly array guaranteed to have at least one element.
When to use
Use when non-emptiness must be tracked at the type level while preventing mutation.
Many Array module functions accept or return this type.
Example (Typing a non-empty array)
import type { Array } from "effect"
const nonEmpty: Array.NonEmptyReadonlyArray<number> = [1, 2, 3]
const head: number = nonEmpty[0] // guaranteed to exist
NonEmptyReadonlyArray<function (type parameter) In in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>In>) => function (type parameter) S in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>S
): interface Sink<out A, in In = unknown, out L = never, out E = never, out R = never>A Sink<A, In, L, E, R> is used to consume elements produced by a Stream.
You can think of a sink as a function that will consume a variable amount of
In elements (could be 0, 1, or many), might fail with an error of type E,
and will eventually yield a value of type A together with a remainder of
type L (i.e. any leftovers).
Example (Running a sink with a stream)
import { Effect, Sink, Stream } from "effect"
// Create a simple sink that always succeeds with a value
const sink: Sink.Sink<number> = Sink.succeed(42)
// Use the sink to consume a stream
const stream = Stream.make(1, 2, 3)
const program = Stream.run(stream, sink)
Effect.runPromise(program).then(console.log)
// Output: 42
Namespace containing types and interfaces for Sink variance and type relationships.
Sink<function (type parameter) S in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>S, function (type parameter) In in <S, In>(initial: LazyArg<S>, f: (s: S, input: NonEmptyReadonlyArray<In>) => S): Sink<S, In>In> =>
const fromTransform: <
In,
A,
E,
R,
L = never
>(
transform: (
upstream: Pull.Pull<
NonEmptyReadonlyArray<In>,
never,
void
>,
scope: Scope.Scope
) => Effect.Effect<End<A, L>, E, R>
) => Sink<A, In, L, E, R>
Creates a Sink from a low-level transform function.
Details
The transform receives the upstream pull of non-empty input arrays and the
active scope, and returns an effect that completes with the sink's End
value.
fromTransform((upstream: Pull.Pull<
readonly [In, ...In[]],
never,
void,
never
>
(parameter) upstream: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
let state: Sstate = initial: LazyArg<S>initial()
return upstream: Pull.Pull<
readonly [In, ...In[]],
never,
void,
never
>
(parameter) upstream: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
Pipeable.pipe<Pull.Pull<readonly [In, ...In[]], never, void, never>, Effect.Effect<void, Cause.Done<void>, never>, Effect.Effect<never, Cause.Done<void>, never>, Effect.Effect<readonly [S], never, never>>(this: Pull.Pull<...>, ab: (_: Pull.Pull<readonly [In, ...In[]], never, void, never>) => Effect.Effect<void, Cause.Done<void>, never>, bc: (_: Effect.Effect<void, Cause.Done<void>, never>) => Effect.Effect<never, Cause.Done<void>, never>, cd: (_: Effect.Effect<never, Cause.Done<void>, never>) => Effect.Effect<...>): Effect.Effect<...> (+21 overloads)pipe(
import EffectEffect.const flatMap: {
<A, B, E1, R1>(
f: (a: A) => Effect<B, E1, R1>
): <E, R>(
self: Effect<A, E, R>
) => Effect<B, E1 | E, R1 | R>
<A, E, R, B, E1, R1>(
self: Effect<A, E, R>,
f: (a: A) => Effect<B, E1, R1>
): Effect<B, E | E1, R | R1>
}
arr: readonly [In, ...In[]](parameter) arr: {
0: In;
length: number;
toString: () => string;
toLocaleString: { (): string; (locales: string | string[], options?: Intl.NumberFormatOptions & Intl.DateTimeFormatOptions): string };
concat: { (...items: Array<ConcatArray<In>>): Array<In>; (...items: Array<In | ConcatArray<In>>): Array<In> };
join: (separator?: string) => string;
slice: (start?: number, end?: number) => Array<In>;
indexOf: (searchElement: In, fromIndex?: number) => number;
lastIndexOf: (searchElement: In, fromIndex?: number) => number;
every: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): this is readonly S[]; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): boolean };
some: (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any) => boolean;
forEach: (callbackfn: (value: In, index: number, array: ReadonlyArray<In>) => void, thisArg?: any) => void;
map: (callbackfn: (value: In, index: number, array: ReadonlyArray<In>) => U, thisArg?: any) => Array<U>;
filter: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): Array<S>; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): Array<In> };
reduce: { (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In): In; (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In, initialValue: In): I…;
reduceRight: { (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In): In; (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In, initialValue: In): I…;
find: { (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => value is S, thisArg?: any): S | undefined; (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => unknown, thisArg?: any): In | undefined };
findIndex: (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => unknown, thisArg?: any) => number;
entries: () => ArrayIterator<[number, In]>;
keys: () => ArrayIterator<number>;
values: () => ArrayIterator<In>;
includes: (searchElement: In, fromIndex?: number) => boolean;
flatMap: (callback: (this: This, value: In, index: number, array: Array<In>) => U | ReadonlyArray<U>, thisArg?: This | undefined) => Array<U>;
flat: (this: A, depth?: D | undefined) => Array<FlatArray<A, D>>;
at: (index: number) => In | undefined;
findLast: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): S | undefined; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): In | undefined };
findLastIndex: (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any) => number;
toReversed: () => Array<In>;
toSorted: (compareFn?: ((a: In, b: In) => number) | undefined) => Array<In>;
toSpliced: { (start: number, deleteCount: number, ...items: Array<In>): Array<In>; (start: number, deleteCount?: number): Array<In> };
with: (index: number, value: In) => Array<In>;
}
let state: Sstate = f: (
s: S,
input: NonEmptyReadonlyArray<In>
) => S
let state: Sstate, arr: readonly [In, ...In[]](parameter) arr: {
0: In;
length: number;
toString: () => string;
toLocaleString: { (): string; (locales: string | string[], options?: Intl.NumberFormatOptions & Intl.DateTimeFormatOptions): string };
concat: { (...items: Array<ConcatArray<In>>): Array<In>; (...items: Array<In | ConcatArray<In>>): Array<In> };
join: (separator?: string) => string;
slice: (start?: number, end?: number) => Array<In>;
indexOf: (searchElement: In, fromIndex?: number) => number;
lastIndexOf: (searchElement: In, fromIndex?: number) => number;
every: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): this is readonly S[]; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): boolean };
some: (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any) => boolean;
forEach: (callbackfn: (value: In, index: number, array: ReadonlyArray<In>) => void, thisArg?: any) => void;
map: (callbackfn: (value: In, index: number, array: ReadonlyArray<In>) => U, thisArg?: any) => Array<U>;
filter: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): Array<S>; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): Array<In> };
reduce: { (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In): In; (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In, initialValue: In): I…;
reduceRight: { (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In): In; (callbackfn: (previousValue: In, currentValue: In, currentIndex: number, array: ReadonlyArray<In>) => In, initialValue: In): I…;
find: { (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => value is S, thisArg?: any): S | undefined; (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => unknown, thisArg?: any): In | undefined };
findIndex: (predicate: (value: In, index: number, obj: ReadonlyArray<In>) => unknown, thisArg?: any) => number;
entries: () => ArrayIterator<[number, In]>;
keys: () => ArrayIterator<number>;
values: () => ArrayIterator<In>;
includes: (searchElement: In, fromIndex?: number) => boolean;
flatMap: (callback: (this: This, value: In, index: number, array: Array<In>) => U | ReadonlyArray<U>, thisArg?: This | undefined) => Array<U>;
flat: (this: A, depth?: D | undefined) => Array<FlatArray<A, D>>;
at: (index: number) => In | undefined;
findLast: { (predicate: (value: In, index: number, array: ReadonlyArray<In>) => value is S, thisArg?: any): S | undefined; (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any): In | undefined };
findLastIndex: (predicate: (value: In, index: number, array: ReadonlyArray<In>) => unknown, thisArg?: any) => number;
toReversed: () => Array<In>;
toSorted: (compareFn?: ((a: In, b: In) => number) | undefined) => Array<In>;
toSpliced: { (start: number, deleteCount: number, ...items: Array<In>): Array<In>; (start: number, deleteCount?: number): Array<In> };
with: (index: number, value: In) => Array<In>;
}
import EffectEffect.const void: Effect.Effect<void, never, never>(alias) const void: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
Returns an effect that succeeds with void.
void
}),
import EffectEffect.const forever: <
Arg extends
| Effect<any, any, any>
| {
readonly disableYield?:
| boolean
| undefined
}
| undefined = {
readonly disableYield?: boolean | undefined
}
>(
effectOrOptions?: Arg,
options?:
| {
readonly disableYield?:
| boolean
| undefined
}
| undefined
) => [Arg] extends [
Effect<infer _A, infer _E, infer _R>
]
? Effect<never, _E, _R>
: <A, E, R>(
self: Effect<A, E, R>
) => Effect<never, E, R>
Repeats this effect forever (until the first error).
Example (Repeating forever)
import { Console, Effect, Fiber } from "effect"
const task = Effect.gen(function*() {
yield* Console.log("Task running...")
yield* Effect.sleep("1 second")
})
// This will run forever, printing every second
const program = task.pipe(Effect.forever)
// This will run forever, without yielding every iteration
const programNoYield = task.pipe(Effect.forever({ disableYield: true }))
// Run for 5 seconds then interrupt
const timedProgram = Effect.gen(function*() {
const fiber = yield* Effect.forkChild(program)
yield* Effect.sleep("5 seconds")
yield* Fiber.interrupt(fiber)
})
forever({ disableYield: truedisableYield: true }),
import PullPull.const catchDone: {
<E, A2, E2, R2>(
f: (
leftover: Cause.Done.Extract<E>
) => Effect<A2, E2, R2>
): <A, R>(
self: Effect<A, E, R>
) => Effect<A | A2, ExcludeDone<E> | E2, R | R2>
<A, R, E, A2, E2, R2>(
self: Effect<A, E, R>,
f: (
leftover: Cause.Done.Extract<E>
) => Effect<A2, E2, R2>
): Effect<A | A2, ExcludeDone<E> | E2, R | R2>
}
import EffectEffect.const succeed: <A>(value: A) => Effect<A>Creates an Effect that always succeeds with a given value.
When to use
Use when an effect should complete successfully with a specific value without any errors
or external dependencies.
Example (Creating a successful effect)
import { Effect } from "effect"
// Creating an effect that represents a successful scenario
//
// ┌─── Effect<number, never, never>
// ▼
const success = Effect.succeed(42)
succeed([let state: Sstate] as type const = readonly [S]const))
)
})Referenced by 4 symbols