<A, E, R, B, E2, R2, EX, RX>(
self: Stream<A, E, R>,
f: (
pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>,
scope: Scope.Scope
) => Effect.Effect<
Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>,
EX,
RX
>
): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>Derives a stream by transforming its pull effect.
Example (Transforming a pull effect)
import { Console, Effect, Stream } from "effect"
const stream = Stream.make(1, 2, 3)
const transformed = Stream.transformPull(stream, (pull) => Effect.succeed(pull))
const program = Effect.gen(function*() {
const values = yield* Stream.runCollect(transformed)
yield* Console.log(values)
})
Effect.runPromise(program)
// Output: [ 1, 2, 3 ]constructors
Source effect/Stream.ts:64213 lines
export const const transformPull: <
A,
E,
R,
B,
E2,
R2,
EX,
RX
>(
self: Stream<A, E, R>,
f: (
pull: Pull.Pull<
Arr.NonEmptyReadonlyArray<A>,
E,
void
>,
scope: Scope.Scope
) => Effect.Effect<
Pull.Pull<
Arr.NonEmptyReadonlyArray<B>,
E2,
void,
R2
>,
EX,
RX
>
) => Stream<
B,
EX | Pull.ExcludeDone<E2>,
R | R2 | RX
>
Derives a stream by transforming its pull effect.
Example (Transforming a pull effect)
import { Console, Effect, Stream } from "effect"
const stream = Stream.make(1, 2, 3)
const transformed = Stream.transformPull(stream, (pull) => Effect.succeed(pull))
const program = Effect.gen(function*() {
const values = yield* Stream.runCollect(transformed)
yield* Console.log(values)
})
Effect.runPromise(program)
// Output: [ 1, 2, 3 ]
transformPull = <function (type parameter) A in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>A, function (type parameter) E in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>E, function (type parameter) R in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>R, function (type parameter) B in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>B, function (type parameter) E2 in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>E2, function (type parameter) R2 in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>R2, function (type parameter) EX in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>EX, function (type parameter) RX in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>RX>(
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, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>A, function (type parameter) E in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>E, function (type parameter) R in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>R>,
f: (
pull: Pull.Pull<
Arr.NonEmptyReadonlyArray<A>,
E,
void
>,
scope: Scope.Scope
) => Effect.Effect<
Pull.Pull<
Arr.NonEmptyReadonlyArray<B>,
E2,
void,
R2
>,
EX,
RX
>
pull: Pull.Pull<
Arr.NonEmptyReadonlyArray<A>,
E,
void
>
(parameter) pull: {
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;
}
import PullPull.type Pull.Pull = /*unresolved*/ anyPull<import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) A in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>A>, function (type parameter) E in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>E, void>, scope: Scope.Scope(parameter) scope: {
strategy: "sequential" | "parallel";
state: State.Open | State.Closed | State.Empty;
}
import ScopeScope.type Scope.Scope = /*unresolved*/ anyScope) => import EffectEffect.type Effect.Effect = /*unresolved*/ anyEffect<
import PullPull.type Pull.Pull = /*unresolved*/ anyPull<import ArrArr.type Arr.NonEmptyReadonlyArray = /*unresolved*/ anyNonEmptyReadonlyArray<function (type parameter) B in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>B>, function (type parameter) E2 in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>E2, void, function (type parameter) R2 in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>R2>,
function (type parameter) EX in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>EX,
function (type parameter) RX in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>RX
>
): 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, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>B, function (type parameter) EX in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>EX | import PullPull.type Pull.ExcludeDone = /*unresolved*/ anyExcludeDone<function (type parameter) E2 in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>E2>, function (type parameter) R in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>R | function (type parameter) R2 in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>R2 | function (type parameter) RX in <A, E, R, B, E2, R2, EX, RX>(self: Stream<A, E, R>, f: (pull: Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E, void>, scope: Scope.Scope) => Effect.Effect<Pull.Pull<Arr.NonEmptyReadonlyArray<B>, E2, void, R2>, EX, RX>): Stream<B, EX | Pull.ExcludeDone<E2>, R | R2 | RX>RX> =>
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.fromTransform((_: Pull.Pull<
unknown,
unknown,
unknown,
never
>
(parameter) _: {
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;
}
scope: Scope.Scope(parameter) scope: {
strategy: "sequential" | "parallel";
state: State.Open | State.Closed | State.Empty;
}
import EffectEffect.flatMap(import ChannelChannel.toPullScoped(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; <…;
}
scope: Scope.Scope(parameter) scope: {
strategy: "sequential" | "parallel";
state: State.Open | State.Closed | State.Empty;
}
pull: Pull.Pull<
readonly [A, ...A[]],
E,
void,
R
>
(parameter) pull: {
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;
}
f: (
pull: Pull.Pull<
Arr.NonEmptyReadonlyArray<A>,
E,
void
>,
scope: Scope.Scope
) => Effect.Effect<
Pull.Pull<
Arr.NonEmptyReadonlyArray<B>,
E2,
void,
R2
>,
EX,
RX
>
pull: Pull.Pull<
readonly [A, ...A[]],
E,
void,
R
>
(parameter) pull: {
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;
}
scope: Scope.Scope(parameter) scope: {
strategy: "sequential" | "parallel";
state: State.Open | State.Closed | State.Empty;
}
Referenced by 17 symbols
Stream.changesWithStream.changesWithEffectStream.debounceStream.dropStream.dropRightStream.dropWhileStream.dropWhileEffectStream.dropWhileFilterStream.groupAdjacentByStream.rechunkStream.slidingSizeStream.takeUntilStream.takeUntilEffectStream.takeWhileStream.takeWhileFilterStream.timeoutOrElseStream.transduce