<A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>Creates a lazily constructed stream.
Details
The stream factory is evaluated each time the stream is run.
Example (Creating a lazily constructed stream)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
const values = yield* Stream.suspend(() => Stream.make(1, 2, 3)).pipe(Stream.runCollect)
yield* Console.log(values)
})
Effect.runPromise(program)
// Output: [ 1, 2, 3 ]export const const suspend: <A, E, R>(
stream: LazyArg<Stream<A, E, R>>
) => Stream<A, E, R>
Creates a lazily constructed stream.
Details
The stream factory is evaluated each time the stream is run.
Example (Creating a lazily constructed stream)
import { Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
const values = yield* Stream.suspend(() => Stream.make(1, 2, 3)).pipe(Stream.runCollect)
yield* Console.log(values)
})
Effect.runPromise(program)
// Output: [ 1, 2, 3 ]
suspend = <function (type parameter) A in <A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>A, function (type parameter) E in <A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>E, function (type parameter) R in <A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>R>(stream: LazyArg<Stream<A, E, R>>stream: import LazyArgLazyArg<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>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>A, function (type parameter) E in <A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>E, function (type parameter) R in <A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, 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, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>A, function (type parameter) E in <A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>E, function (type parameter) R in <A, E, R>(stream: LazyArg<Stream<A, E, R>>): Stream<A, E, R>R> =>
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.suspend(() => stream: LazyArg<Stream<A, E, R>>stream().channel))