<A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>Unwraps Take values, emitting elements from non-empty arrays and ending or
failing when the Exit signals completion.
Example (Flattening Take values)
import { Array, Console, Effect, Exit, Stream } from "effect"
const program = Effect.gen(function*() {
const takes = Stream.make(
Array.make(1, 2),
Array.make(3),
Exit.succeed<void>(undefined)
)
const values = yield* Stream.flattenTake(takes).pipe(Stream.runCollect)
yield* Console.log(values)
})
Effect.runPromise(program)
// Output: [ 1, 2, 3 ]export const const flattenTake: <A, E, E2, R>(
self: Stream<Take.Take<A, E>, E2, R>
) => Stream<A, E | E2, R>
Unwraps Take values, emitting elements from non-empty arrays and ending or
failing when the Exit signals completion.
Example (Flattening Take values)
import { Array, Console, Effect, Exit, Stream } from "effect"
const program = Effect.gen(function*() {
const takes = Stream.make(
Array.make(1, 2),
Array.make(3),
Exit.succeed<void>(undefined)
)
const values = yield* Stream.flattenTake(takes).pipe(Stream.runCollect)
yield* Console.log(values)
})
Effect.runPromise(program)
// Output: [ 1, 2, 3 ]
flattenTake = <function (type parameter) A in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>A, function (type parameter) E in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>E, function (type parameter) E2 in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>E2, function (type parameter) R in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>R>(self: Stream<Take.Take<A, E>, E2, 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<import TakeTake.type Take<A, E = never, Done = void> =
| readonly [A, ...A[]]
| Exit.Exit<Done, E>
Represents one pull result: either a non-empty batch of values, a failure
Exit, or a successful Exit that signals completion with a Done value.
When to use
Use to store, transfer, or interpret pull results later while preserving
emitted values, failures, and normal completion.
Take<function (type parameter) A in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>A, function (type parameter) E in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>E>, function (type parameter) E2 in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>E2, function (type parameter) R in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>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) A in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>A, function (type parameter) E in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>E | function (type parameter) E2 in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>E2, function (type parameter) R in <A, E, E2, R>(self: Stream<Take.Take<A, E>, E2, R>): Stream<A, E | E2, R>R> =>
self: Stream<Take.Take<A, E>, E2, 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<Take<A, E, void>, E2, R>.channel: Channel.Channel<Arr.NonEmptyReadonlyArray<A>, E, void, unknown, unknown, unknown, R>(property) Stream<Take<A, E, void>, E2, R>.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; <…;
}
Pipeable.pipe<Channel.Channel<readonly [Take.Take<A, E, void>, ...Take.Take<A, E, void>[]], E2, void, unknown, unknown, unknown, R>, Channel.Channel<Take.Take<A, E, void>, E2, void, unknown, unknown, unknown, R>, Channel.Channel<readonly [A, ...A[]], E | E2, void, unknown, unknown, unknown, R>, Stream<A, E | E2, R>>(this: Channel.Channel<...>, ab: (_: Channel.Channel<readonly [Take.Take<A, E, void>, ...Take.Take<A, E, void>[]], E2, void, unknown, unknown, unknown, R>) => Channel.Channel<Take.Take<A, E, void>, E2, void, unknown, unknown, unknown, R>, bc: (_: Channel.Channel<...>) => Channel.Channel<...>, cd: (_: Channel.Channel<...>) => Stream<...>): Stream<...> (+21 overloads)pipe(
import ChannelChannel.const flattenArray: <
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>(
self: Channel<
ReadonlyArray<OutElem>,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
) => Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
Flattens a channel that outputs arrays into a channel that outputs individual elements.
Example (Flattening arrays of channel output)
import { Channel, Data } from "effect"
class FlattenError extends Data.TaggedError("FlattenError")<{
readonly message: string
}> {}
// Create a channel that outputs arrays
const arrayChannel = Channel.fromIterable([
[1, 2, 3],
[4, 5],
[6, 7, 8, 9]
])
// Flatten the arrays into individual elements
const flattenedChannel = Channel.flattenArray(arrayChannel)
// Outputs: 1, 2, 3, 4, 5, 6, 7, 8, 9
flattenArray,
import ChannelChannel.const flattenTake: <
OutElem,
OutErr,
OutDone,
OutErr2,
OutDone2,
InElem,
InErr,
InDone,
Env
>(
self: Channel<
Take.Take<OutElem, OutErr, OutDone>,
OutErr2,
OutDone2,
InElem,
InErr,
InDone,
Env
>
) => Channel<
Arr.NonEmptyReadonlyArray<OutElem>,
OutErr | OutErr2,
OutDone,
InElem,
InErr,
InDone,
Env
>
Flattens a channel that emits Take values into a channel that emits the
Take outputs directly.
Details
Output Take values are emitted as non-empty arrays. Failed Take values
fail the returned channel. Done Take values complete the returned channel.
flattenTake,
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
)