<A, B, E2, R2>(
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>
): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>
<A, E, R, B, E2, R2>(
self: Stream<A, E, R>,
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>
): Stream<B, E | E2, R | R2>Maps over non-empty array chunks emitted by the stream effectfully.
When to use
Use when transformation needs to see and replace each non-empty emitted chunk effectfully instead of mapping individual stream elements.
Example (Effectfully mapping stream chunks)
import { Array, Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
const result = yield* Stream.fromArray([1, 2, 3, 4]).pipe(
Stream.rechunk(2),
Stream.mapArrayEffect((chunk, index) =>
Effect.succeed(Array.map(chunk, (n) => n + index * 10))
),
Stream.runCollect
)
yield* Console.log(result)
})
Effect.runPromise(program)
// Output: [1, 2, 13, 14]mapping
Source effect/Stream.ts:213612 lines
export const const mapArrayEffect: {
<A, B, E2, R2>(
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<
Arr.NonEmptyReadonlyArray<B>,
E2,
R2
>
): <E, R>(
self: Stream<A, E, R>
) => Stream<B, E | E2, R | R2>
<A, E, R, B, E2, R2>(
self: Stream<A, E, R>,
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<
Arr.NonEmptyReadonlyArray<B>,
E2,
R2
>
): Stream<B, E | E2, R | R2>
}
Maps over non-empty array chunks emitted by the stream effectfully.
When to use
Use when transformation needs to see and replace each non-empty emitted chunk
effectfully instead of mapping individual stream elements.
Example (Effectfully mapping stream chunks)
import { Array, Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
const result = yield* Stream.fromArray([1, 2, 3, 4]).pipe(
Stream.rechunk(2),
Stream.mapArrayEffect((chunk, index) =>
Effect.succeed(Array.map(chunk, (n) => n + index * 10))
),
Stream.runCollect
)
yield* Console.log(result)
})
Effect.runPromise(program)
// Output: [1, 2, 13, 14]
mapArrayEffect: {
<function (type parameter) A in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>A, function (type parameter) B in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>B, function (type parameter) E2 in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>E2, function (type parameter) R2 in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>R2>(
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<
Arr.NonEmptyReadonlyArray<B>,
E2,
R2
>
a: Arr.NonEmptyReadonlyArray<A>(parameter) a: {
0: A;
length: number;
toString: () => string;
toLocaleString: { (): string; (locales: string | string[], options?: Intl.NumberFormatOptions & Intl.DateTimeFormatOptions): string };
concat: { (...items: Array<ConcatArray<A>>): Array<A>; (...items: Array<A | ConcatArray<A>>): Array<A> };
join: (separator?: string) => string;
slice: (start?: number, end?: number) => Array<A>;
indexOf: (searchElement: A, fromIndex?: number) => number;
lastIndexOf: (searchElement: A, fromIndex?: number) => number;
every: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): this is readonly S[]; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): boolean };
some: (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any) => boolean;
forEach: (callbackfn: (value: A, index: number, array: ReadonlyArray<A>) => void, thisArg?: any) => void;
map: (callbackfn: (value: A, index: number, array: ReadonlyArray<A>) => U, thisArg?: any) => Array<U>;
filter: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): Array<S>; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): Array<A> };
reduce: { (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A): A; (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A, initialValue: A): A; (callbac…;
reduceRight: { (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A): A; (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A, initialValue: A): A; (callbac…;
find: { (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => value is S, thisArg?: any): S | undefined; (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => unknown, thisArg?: any): A | undefined };
findIndex: (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => unknown, thisArg?: any) => number;
entries: () => ArrayIterator<[number, A]>;
keys: () => ArrayIterator<number>;
values: () => ArrayIterator<A>;
includes: (searchElement: A, fromIndex?: number) => boolean;
flatMap: (callback: (this: This, value: A, index: number, array: Array<A>) => U | ReadonlyArray<U>, thisArg?: This | undefined) => Array<U>;
flat: (this: A, depth?: D | undefined) => Array<FlatArray<A, D>>;
at: (index: number) => A | undefined;
findLast: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): S | undefined; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): A | undefined };
findLastIndex: (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any) => number;
toReversed: () => Array<A>;
toSorted: (compareFn?: ((a: A, b: A) => number) | undefined) => Array<A>;
toSpliced: { (start: number, deleteCount: number, ...items: Array<A>): Array<A>; (start: number, deleteCount?: number): Array<A> };
with: (index: number, value: A) => Array<A>;
}
import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) A in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>A>, i: numberi: number) => import EffectEffect.type Effect.Effect = /*unresolved*/ anyEffect<import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) B in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>B>, function (type parameter) E2 in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>E2, function (type parameter) R2 in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>R2>
): <function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E | E2, R | R2>E, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E | E2, R | R2>R>(self: Stream<A, E, R>(parameter) self: {
channel: Channel.Channel<Arr.NonEmptyReadonlyArray<A>, E, void, unknown, unknown, unknown, R>;
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; <…;
}
interface Stream<out A, out E = never, out R = never>A Stream<A, E, R> describes a program that can emit many A values, fail
with E, and require R.
Details
Streams are pull-based with backpressure and emit chunks to amortize effect
evaluation. They support monadic composition and error handling similar to
Effect, adapted for multiple values.
Example (Creating and consuming streams)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
yield* Stream.make(1, 2, 3).pipe(
Stream.map((n) => n * 2),
Stream.runForEach((n) => Console.log(n))
)
})
Effect.runPromise(program)
// Output:
// 2
// 4
// 6
Stream<function (type parameter) A in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>A, function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E | E2, R | R2>E, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E | E2, R | R2>R>) => interface Stream<out A, out E = never, out R = never>A Stream<A, E, R> describes a program that can emit many A values, fail
with E, and require R.
Details
Streams are pull-based with backpressure and emit chunks to amortize effect
evaluation. They support monadic composition and error handling similar to
Effect, adapted for multiple values.
Example (Creating and consuming streams)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
yield* Stream.make(1, 2, 3).pipe(
Stream.map((n) => n * 2),
Stream.runForEach((n) => Console.log(n))
)
})
Effect.runPromise(program)
// Output:
// 2
// 4
// 6
Stream<function (type parameter) B in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>B, function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E | E2, R | R2>E | function (type parameter) E2 in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>E2, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E | E2, R | R2>R | function (type parameter) R2 in <A, B, E2, R2>(f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | E2, R | R2>R2>
<function (type parameter) A in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>A, function (type parameter) E in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E, function (type parameter) R in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R, function (type parameter) B in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>B, function (type parameter) E2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E2, function (type parameter) R2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R2>(
self: Stream<A, E, R>(parameter) self: {
channel: Channel.Channel<Arr.NonEmptyReadonlyArray<A>, E, void, unknown, unknown, unknown, R>;
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; <…;
}
interface Stream<out A, out E = never, out R = never>A Stream<A, E, R> describes a program that can emit many A values, fail
with E, and require R.
Details
Streams are pull-based with backpressure and emit chunks to amortize effect
evaluation. They support monadic composition and error handling similar to
Effect, adapted for multiple values.
Example (Creating and consuming streams)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
yield* Stream.make(1, 2, 3).pipe(
Stream.map((n) => n * 2),
Stream.runForEach((n) => Console.log(n))
)
})
Effect.runPromise(program)
// Output:
// 2
// 4
// 6
Stream<function (type parameter) A in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>A, function (type parameter) E in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E, function (type parameter) R in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R>,
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<
Arr.NonEmptyReadonlyArray<B>,
E2,
R2
>
a: Arr.NonEmptyReadonlyArray<A>(parameter) a: {
0: A;
length: number;
toString: () => string;
toLocaleString: { (): string; (locales: string | string[], options?: Intl.NumberFormatOptions & Intl.DateTimeFormatOptions): string };
concat: { (...items: Array<ConcatArray<A>>): Array<A>; (...items: Array<A | ConcatArray<A>>): Array<A> };
join: (separator?: string) => string;
slice: (start?: number, end?: number) => Array<A>;
indexOf: (searchElement: A, fromIndex?: number) => number;
lastIndexOf: (searchElement: A, fromIndex?: number) => number;
every: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): this is readonly S[]; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): boolean };
some: (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any) => boolean;
forEach: (callbackfn: (value: A, index: number, array: ReadonlyArray<A>) => void, thisArg?: any) => void;
map: (callbackfn: (value: A, index: number, array: ReadonlyArray<A>) => U, thisArg?: any) => Array<U>;
filter: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): Array<S>; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): Array<A> };
reduce: { (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A): A; (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A, initialValue: A): A; (callbac…;
reduceRight: { (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A): A; (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A, initialValue: A): A; (callbac…;
find: { (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => value is S, thisArg?: any): S | undefined; (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => unknown, thisArg?: any): A | undefined };
findIndex: (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => unknown, thisArg?: any) => number;
entries: () => ArrayIterator<[number, A]>;
keys: () => ArrayIterator<number>;
values: () => ArrayIterator<A>;
includes: (searchElement: A, fromIndex?: number) => boolean;
flatMap: (callback: (this: This, value: A, index: number, array: Array<A>) => U | ReadonlyArray<U>, thisArg?: This | undefined) => Array<U>;
flat: (this: A, depth?: D | undefined) => Array<FlatArray<A, D>>;
at: (index: number) => A | undefined;
findLast: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): S | undefined; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): A | undefined };
findLastIndex: (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any) => number;
toReversed: () => Array<A>;
toSorted: (compareFn?: ((a: A, b: A) => number) | undefined) => Array<A>;
toSpliced: { (start: number, deleteCount: number, ...items: Array<A>): Array<A>; (start: number, deleteCount?: number): Array<A> };
with: (index: number, value: A) => Array<A>;
}
import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) A in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>A>, i: numberi: number) => import EffectEffect.type Effect.Effect = /*unresolved*/ anyEffect<import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) B in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>B>, function (type parameter) E2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E2, function (type parameter) R2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R2>
): interface Stream<out A, out E = never, out R = never>A Stream<A, E, R> describes a program that can emit many A values, fail
with E, and require R.
Details
Streams are pull-based with backpressure and emit chunks to amortize effect
evaluation. They support monadic composition and error handling similar to
Effect, adapted for multiple values.
Example (Creating and consuming streams)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
yield* Stream.make(1, 2, 3).pipe(
Stream.map((n) => n * 2),
Stream.runForEach((n) => Console.log(n))
)
})
Effect.runPromise(program)
// Output:
// 2
// 4
// 6
Stream<function (type parameter) B in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>B, function (type parameter) E in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E | function (type parameter) E2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E2, function (type parameter) R in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R | function (type parameter) R2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R2>
} = import dualdual(2, <function (type parameter) A in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>A, function (type parameter) E in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E, function (type parameter) R in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R, function (type parameter) B in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>B, function (type parameter) E2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E2, function (type parameter) R2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R2>(
self: Stream<A, E, R>(parameter) self: {
channel: Channel.Channel<Arr.NonEmptyReadonlyArray<A>, E, void, unknown, unknown, unknown, R>;
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; <…;
}
interface Stream<out A, out E = never, out R = never>A Stream<A, E, R> describes a program that can emit many A values, fail
with E, and require R.
Details
Streams are pull-based with backpressure and emit chunks to amortize effect
evaluation. They support monadic composition and error handling similar to
Effect, adapted for multiple values.
Example (Creating and consuming streams)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
yield* Stream.make(1, 2, 3).pipe(
Stream.map((n) => n * 2),
Stream.runForEach((n) => Console.log(n))
)
})
Effect.runPromise(program)
// Output:
// 2
// 4
// 6
Stream<function (type parameter) A in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>A, function (type parameter) E in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E, function (type parameter) R in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R>,
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<
Arr.NonEmptyReadonlyArray<B>,
E2,
R2
>
a: Arr.NonEmptyReadonlyArray<A>(parameter) a: {
0: A;
length: number;
toString: () => string;
toLocaleString: { (): string; (locales: string | string[], options?: Intl.NumberFormatOptions & Intl.DateTimeFormatOptions): string };
concat: { (...items: Array<ConcatArray<A>>): Array<A>; (...items: Array<A | ConcatArray<A>>): Array<A> };
join: (separator?: string) => string;
slice: (start?: number, end?: number) => Array<A>;
indexOf: (searchElement: A, fromIndex?: number) => number;
lastIndexOf: (searchElement: A, fromIndex?: number) => number;
every: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): this is readonly S[]; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): boolean };
some: (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any) => boolean;
forEach: (callbackfn: (value: A, index: number, array: ReadonlyArray<A>) => void, thisArg?: any) => void;
map: (callbackfn: (value: A, index: number, array: ReadonlyArray<A>) => U, thisArg?: any) => Array<U>;
filter: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): Array<S>; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): Array<A> };
reduce: { (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A): A; (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A, initialValue: A): A; (callbac…;
reduceRight: { (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A): A; (callbackfn: (previousValue: A, currentValue: A, currentIndex: number, array: ReadonlyArray<A>) => A, initialValue: A): A; (callbac…;
find: { (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => value is S, thisArg?: any): S | undefined; (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => unknown, thisArg?: any): A | undefined };
findIndex: (predicate: (value: A, index: number, obj: ReadonlyArray<A>) => unknown, thisArg?: any) => number;
entries: () => ArrayIterator<[number, A]>;
keys: () => ArrayIterator<number>;
values: () => ArrayIterator<A>;
includes: (searchElement: A, fromIndex?: number) => boolean;
flatMap: (callback: (this: This, value: A, index: number, array: Array<A>) => U | ReadonlyArray<U>, thisArg?: This | undefined) => Array<U>;
flat: (this: A, depth?: D | undefined) => Array<FlatArray<A, D>>;
at: (index: number) => A | undefined;
findLast: { (predicate: (value: A, index: number, array: ReadonlyArray<A>) => value is S, thisArg?: any): S | undefined; (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any): A | undefined };
findLastIndex: (predicate: (value: A, index: number, array: ReadonlyArray<A>) => unknown, thisArg?: any) => number;
toReversed: () => Array<A>;
toSorted: (compareFn?: ((a: A, b: A) => number) | undefined) => Array<A>;
toSpliced: { (start: number, deleteCount: number, ...items: Array<A>): Array<A>; (start: number, deleteCount?: number): Array<A> };
with: (index: number, value: A) => Array<A>;
}
import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) A in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>A>, i: numberi: number) => import EffectEffect.type Effect.Effect = /*unresolved*/ anyEffect<import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) B in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>B>, function (type parameter) E2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E2, function (type parameter) R2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R2>
): interface Stream<out A, out E = never, out R = never>A Stream<A, E, R> describes a program that can emit many A values, fail
with E, and require R.
Details
Streams are pull-based with backpressure and emit chunks to amortize effect
evaluation. They support monadic composition and error handling similar to
Effect, adapted for multiple values.
Example (Creating and consuming streams)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
yield* Stream.make(1, 2, 3).pipe(
Stream.map((n) => n * 2),
Stream.runForEach((n) => Console.log(n))
)
})
Effect.runPromise(program)
// Output:
// 2
// 4
// 6
Stream<function (type parameter) B in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>B, function (type parameter) E in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E | function (type parameter) E2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>E2, function (type parameter) R in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R | function (type parameter) R2 in <A, E, R, B, E2, R2>(self: Stream<A, E, R>, f: (a: Arr.NonEmptyReadonlyArray<A>, i: number) => Effect.Effect<Arr.NonEmptyReadonlyArray<B>, E2, R2>): Stream<B, E | E2, R | R2>R2> => const fromChannel: <
Arr extends Arr.NonEmptyReadonlyArray<any>,
E,
R
>(
channel: Channel.Channel<
Arr,
E,
void,
unknown,
unknown,
unknown,
R
>
) => Stream<
Arr extends Arr.NonEmptyReadonlyArray<infer A>
? A
: never,
E,
R
>
Creates a stream from a array-emitting Channel.
Example (Creating a stream from an array-emitting channel)
import { Channel, Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
const channel = Channel.succeed([1, 2, 3] as const)
const stream = Stream.fromChannel(channel)
const result = yield* Stream.runCollect(stream)
yield* Console.log(result)
})
// Output: [ 1, 2, 3 ]
fromChannel(import ChannelChannel.mapEffect(self: Stream<A, E, R>(parameter) self: {
channel: Channel.Channel<Arr.NonEmptyReadonlyArray<A>, E, void, unknown, unknown, unknown, R>;
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; <…;
}
Stream<out A, out E = never, out R = never>.channel: Channel.Channel<Arr.NonEmptyReadonlyArray<A>, E, void, unknown, unknown, unknown, R>(property) Stream<out A, out E = never, out R = never>.channel: {
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; <…;
}
f: (
a: Arr.NonEmptyReadonlyArray<A>,
i: number
) => Effect.Effect<
Arr.NonEmptyReadonlyArray<B>,
E2,
R2
>