<A, B, X, EX, RX>(
filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>
): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>
<A, E, R, B, X, EX, RX>(
self: Stream<A, E, R>,
filter: Filter.FilterEffect<A, B, X, EX, RX>
): Stream<B, E | EX, R | RX>Filters and maps elements in one pass effectfully using a FilterEffect.
When to use
Use to apply effectful logic that can reject stream elements or emit transformed values before they continue downstream.
Details
Result.succeed values are emitted, Result.fail values are skipped, and
effect failures fail the stream.
Source effect/Stream.ts:441515 lines
export const const filterMapEffect: {
<A, B, X, EX, RX>(
filter: Filter.FilterEffect<
NoInfer<A>,
B,
X,
EX,
RX
>
): <E, R>(
self: Stream<A, E, R>
) => Stream<B, E | EX, R | RX>
<A, E, R, B, X, EX, RX>(
self: Stream<A, E, R>,
filter: Filter.FilterEffect<A, B, X, EX, RX>
): Stream<B, E | EX, R | RX>
}
Filters and maps elements in one pass effectfully using a FilterEffect.
When to use
Use to apply effectful logic that can reject stream elements or emit
transformed values before they continue downstream.
Details
Result.succeed values are emitted, Result.fail values are skipped, and
effect failures fail the stream.
filterMapEffect: {
<function (type parameter) A in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>A, function (type parameter) B in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>B, function (type parameter) X in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>X, function (type parameter) EX in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>EX, function (type parameter) RX in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>RX>(
filter: Filter.FilterEffect<
NoInfer<A>,
B,
X,
EX,
RX
>
import FilterFilter.type Filter.FilterEffect = /*unresolved*/ anyFilterEffect<type NoInfer<A> = [A][A extends any ? 0 : never]Prevents TypeScript from inferring a type parameter from a specific
position.
When to use
Use when a function parameter must match an inferred type without becoming
an inference source.
Details
The parameter using NoInfer must still match the inferred type.
Example (Controlling inference)
import type { Types } from "effect"
declare function withDefault<T>(value: T, fallback: Types.NoInfer<T>): T
// T is inferred as "a" | "b" from the first argument only
const result = withDefault<"a" | "b">("a", "b")
NoInfer<function (type parameter) A in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>A>, function (type parameter) B in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>B, function (type parameter) X in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>X, function (type parameter) EX in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>EX, function (type parameter) RX in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>RX>
): <function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E | EX, R | RX>E, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E | EX, R | RX>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, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>A, function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E | EX, R | RX>E, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E | EX, R | RX>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, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>B, function (type parameter) E in <E, R>(self: Stream<A, E, R>): Stream<B, E | EX, R | RX>E | function (type parameter) EX in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>EX, function (type parameter) R in <E, R>(self: Stream<A, E, R>): Stream<B, E | EX, R | RX>R | function (type parameter) RX in <A, B, X, EX, RX>(filter: Filter.FilterEffect<NoInfer<A>, B, X, EX, RX>): <E, R>(self: Stream<A, E, R>) => Stream<B, E | EX, R | RX>RX>
<function (type parameter) A in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>A, function (type parameter) E in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>E, function (type parameter) R in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>R, function (type parameter) B in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>B, function (type parameter) X in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>X, function (type parameter) EX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>EX, function (type parameter) RX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | 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, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>A, function (type parameter) E in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>E, function (type parameter) R in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>R>,
filter: Filter.FilterEffect<A, B, X, EX, RX>filter: import FilterFilter.type Filter.FilterEffect = /*unresolved*/ anyFilterEffect<function (type parameter) A in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>A, function (type parameter) B in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>B, function (type parameter) X in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>X, function (type parameter) EX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>EX, function (type parameter) RX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | 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, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>B, function (type parameter) E in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>E | function (type parameter) EX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>EX, function (type parameter) R in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>R | function (type parameter) RX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>RX>
} = import dualdual(
2,
<function (type parameter) A in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>A, function (type parameter) E in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>E, function (type parameter) R in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>R, function (type parameter) B in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>B, function (type parameter) X in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>X, function (type parameter) EX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>EX, function (type parameter) RX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | 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, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>A, function (type parameter) E in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>E, function (type parameter) R in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>R>,
filter: Filter.FilterEffect<A, B, X, EX, RX>filter: import FilterFilter.type Filter.FilterEffect = /*unresolved*/ anyFilterEffect<function (type parameter) A in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>A, function (type parameter) B in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>B, function (type parameter) X in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>X, function (type parameter) EX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>EX, function (type parameter) RX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | 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, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>B, function (type parameter) E in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>E | function (type parameter) EX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>EX, function (type parameter) R in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | RX>R | function (type parameter) RX in <A, E, R, B, X, EX, RX>(self: Stream<A, E, R>, filter: Filter.FilterEffect<A, B, X, EX, RX>): Stream<B, E | EX, R | 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.filterMapArrayEffect(const toChannel: <A, E, R>(
stream: Stream<A, E, R>
) => Channel.Channel<
Arr.NonEmptyReadonlyArray<A>,
E,
void,
unknown,
unknown,
unknown,
R
>
Creates a channel from a stream.
Example (Converting a stream to a channel)
import { Channel, Console, Effect, Stream } from "effect"
const program = Effect.gen(function*() {
const stream = Stream.make(1, 2, 3)
const channel = Stream.toChannel(stream)
const values = yield* Channel.runCollect(channel)
yield* Console.log(values.flat())
})
Effect.runPromise(program)
// Output: [ 1, 2, 3 ]
toChannel(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; <…;
}
filter: Filter.FilterEffect<A, B, X, EX, RX>filter))
)