<A, B>(f: (a: A, i: number) => B): <E, R>(
self: Stream<A, E, R>
) => Stream<B, E, R>
<A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<
B,
E,
R
>Transforms the elements of this stream using the supplied function.
Example (Mapping stream values)
import { Console, Effect, Stream } from "effect"
const stream = Stream.fromArray([1, 2, 3]).pipe(Stream.map((n, i) => n + i))
const program = Stream.runCollect(stream).pipe(
Effect.tap((values) => Console.log(values))
)
Effect.runPromise(program)
// [ 1, 3, 5 ]mapping
Source effect/Stream.ts:187811 lines
export const const map: {
<A, B>(f: (a: A, i: number) => B): <E, R>(
self: Stream<A, E, R>
) => Stream<B, E, R>
<A, E, R, B>(
self: Stream<A, E, R>,
f: (a: A, i: number) => B
): Stream<B, E, R>
}
Transforms the elements of this stream using the supplied function.
Example (Mapping stream values)
import { Console, Effect, Stream } from "effect"
const stream = Stream.fromArray([1, 2, 3]).pipe(Stream.map((n, i) => n + i))
const program = Stream.runCollect(stream).pipe(
Effect.tap((values) => Console.log(values))
)
Effect.runPromise(program)
// [ 1, 3, 5 ]
map: {
<function (type parameter) A in <A, B>(f: (a: A, i: number) => B): <E, R>(self: Stream<A, E, R>) => Stream<B, E, R>A, function (type parameter) B in <A, B>(f: (a: A, i: number) => B): <E, R>(self: Stream<A, E, R>) => Stream<B, E, R>B>(f: (a: A, i: number) => Bf: (a: Aa: function (type parameter) A in <A, B>(f: (a: A, i: number) => B): <E, R>(self: Stream<A, E, R>) => Stream<B, E, R>A, i: numberi: number) => function (type parameter) B in <A, B>(f: (a: A, i: number) => B): <E, R>(self: Stream<A, E, R>) => Stream<B, E, R>B): <function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E, R>E, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E, R>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>(f: (a: A, i: number) => B): <E, R>(self: Stream<A, E, R>) => Stream<B, E, R>A, function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E, R>E, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, 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) B in <A, B>(f: (a: A, i: number) => B): <E, R>(self: Stream<A, E, R>) => Stream<B, E, R>B, function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E, R>E, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E, R>R>
<function (type parameter) A in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>A, function (type parameter) E in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>R, function (type parameter) B in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>B>(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>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>A, function (type parameter) E in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>R>, f: (a: A, i: number) => Bf: (a: Aa: function (type parameter) A in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>A, i: numberi: number) => function (type parameter) B in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>B): 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>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>B, function (type parameter) E in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>R>
} = import dualdual(2, <function (type parameter) A in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>A, function (type parameter) E in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>R, function (type parameter) B in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>B>(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>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>A, function (type parameter) E in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>R>, f: (a: A, i: number) => Bf: (a: Aa: function (type parameter) A in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>A, i: numberi: number) => function (type parameter) B in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>B): 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>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>B, function (type parameter) E in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>E, function (type parameter) R in <A, E, R, B>(self: Stream<A, E, R>, f: (a: A, i: number) => B): Stream<B, E, R>R> =>
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(() => {
let let i: numberi = 0
return 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.map(
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; <…;
}
import ArrArr.map((o: anyo) => f: (a: A, i: number) => Bf(o: anyo, let i: numberi++))
))
}))Referenced by 14 symbols
Stream.bindStream.bindToStream.crossWithStream.decodeTextStream.encodeTextStream.mapBothStream.mergeResultStream.resultStream.zipLatestWithStream.zipWithIndexDynamicConfig.layer (hyperlink-ts)Hyperlink.mapSubscribable (hyperlink-ts)MultiNode.mergeNodeStreamsByNode (hyperlink-ts)NodeMultipart.stream (platform-node)