<
N extends string,
OutElem extends object,
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>(
name: Exclude<N, keyof OutElem>,
f: (
a: NoInfer<OutElem>
) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>,
options?: {
readonly concurrency?: number | "unbounded" | undefined
readonly bufferSize?: number | undefined
}
): <OutErr, OutDone, InElem, InErr, InDone, Env>(
self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>
) => Channel<
{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B },
OutErr2 | OutErr,
OutDone,
InElem & InElem2,
InErr & InErr2,
InDone & InDone2,
Env2 | Env
>
<
OutElem extends object,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env,
N extends string,
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>(
self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>,
name: Exclude<N, keyof OutElem>,
f: (
a: NoInfer<OutElem>
) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>,
options?: {
readonly concurrency?: number | "unbounded" | undefined
readonly bufferSize?: number | undefined
}
): Channel<
{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B },
OutErr2 | OutErr,
OutDone,
InElem & InElem2,
InErr & InErr2,
InDone & InDone2,
Env2 | Env
>Adds a field to each object emitted by a channel by running another channel derived from that object.
Details
The field name must not already exist on the emitted object. The derived
channel's output becomes the value of the new field. options.concurrency
and options.bufferSize control how derived channels are flattened.
do notation
Source effect/Channel.ts:752590 lines
export const const bind: {
<
N extends string,
OutElem extends object,
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>(
name: Exclude<N, keyof OutElem>,
f: (
a: NoInfer<OutElem>
) => Channel<
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>,
options?: {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
): <
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
) => Channel<
{
[K in
| N
| keyof OutElem]: K extends keyof OutElem
? OutElem[K]
: B
},
OutErr2 | OutErr,
OutDone,
InElem & InElem2,
InErr & InErr2,
InDone & InDone2,
Env2 | Env
>
<
OutElem extends object,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env,
N extends string,
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>,
name: Exclude<N, keyof OutElem>,
f: (
a: NoInfer<OutElem>
) => Channel<
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>,
options?: {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
): Channel<
{
[K in
| N
| keyof OutElem]: K extends keyof OutElem
? OutElem[K]
: B
},
OutErr2 | OutErr,
OutDone,
InElem & InElem2,
InErr & InErr2,
InDone & InDone2,
Env2 | Env
>
}
Adds a field to each object emitted by a channel by running another channel
derived from that object.
Details
The field name must not already exist on the emitted object. The derived
channel's output becomes the value of the new field. options.concurrency
and options.bufferSize control how derived channels are flattened.
bind: {
<function (type parameter) N in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) B in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
name: Exclude<N, keyof OutElem>name: type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) N in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
f: (
a: NoInfer<OutElem>
) => Channel<
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>
a: NoInfer<OutElem>a: type NoInfer<T> = intrinsicMarker for non-inference type position
NoInfer<function (type parameter) OutElem in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
interface Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<function (type parameter) B in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
options: | {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
| undefined
concurrency?: number | "unbounded" | undefinedconcurrency?: number | "unbounded" | undefined
readonly bufferSize?: number | undefinedbufferSize?: number | undefined
}
): <function (type parameter) OutErr in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>OutErr, function (type parameter) OutDone in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>OutDone, function (type parameter) InElem in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InElem, function (type parameter) InErr in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InErr, function (type parameter) InDone in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InDone, function (type parameter) Env in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>Env>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
(parameter) self: {
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 Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<function (type parameter) OutElem in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>OutErr, function (type parameter) OutDone in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>OutDone, function (type parameter) InElem in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InElem, function (type parameter) InErr in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InErr, function (type parameter) InDone in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InDone, function (type parameter) Env in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>Env>
) => interface Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<
{ [function (type parameter) KK in function (type parameter) N in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) KK extends keyof function (type parameter) OutElem in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) KK] : function (type parameter) B in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>OutErr,
function (type parameter) OutDone in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>OutDone,
function (type parameter) InElem in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InElem & function (type parameter) InElem2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InErr & function (type parameter) InErr2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>InDone & function (type parameter) InDone2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <N extends string, OutElem extends object, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env in <OutErr, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>Env
>
<
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) N in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) B in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
(parameter) self: {
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 Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
name: Exclude<N, keyof OutElem>name: type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) N in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
f: (
a: NoInfer<OutElem>
) => Channel<
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>
a: NoInfer<OutElem>a: type NoInfer<T> = intrinsicMarker for non-inference type position
NoInfer<function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
interface Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<function (type parameter) B in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
options: | {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
| undefined
concurrency?: number | "unbounded" | undefinedconcurrency?: number | "unbounded" | undefined
readonly bufferSize?: number | undefinedbufferSize?: number | undefined
}
): interface Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<
{ [function (type parameter) KK in function (type parameter) N in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) KK extends keyof function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) KK] : function (type parameter) B in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
dual<(...args: Array<any>) => any, <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>>(isDataFirst: (args: IArguments) => boolean, body: <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>): ((...args: Array<any>) => any) & (<OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}) => Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>) (+1 overload)
Creates a function that can be called in data-first style or data-last
(pipe-friendly) style.
When to use
Use to expose one implementation through both direct and pipe-friendly
call styles.
Details
Pass either the arity of the uncurried function or a predicate that decides
whether the current call is data-first. Arity is the common case. Use a
predicate when optional arguments make arity ambiguous.
Example (Selecting data-first or data-last style by arity)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(2, (self, that) => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Defining overloads with call signatures)
import { Function, pipe } from "effect"
const sum: {
(that: number): (self: number) => number
(self: number, that: number): number
} = Function.dual(2, (self: number, that: number): number => self + that)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
Example (Selecting data-first or data-last style with a predicate)
import { Function, pipe } from "effect"
const sum = Function.dual<
(that: number) => (self: number) => number,
(self: number, that: number) => number
>(
(args) => args.length === 2,
(self, that) => self + that
)
console.log(sum(2, 3)) // 5
console.log(pipe(2, sum(3))) // 5
dual((args: IArgumentsargs) => const isChannel: (
u: unknown
) => u is Channel<
unknown,
unknown,
unknown,
unknown,
unknown,
unknown,
unknown
>
Checks whether a value is a Channel.
Example (Checking for channels)
import { Channel } from "effect"
const channel = Channel.succeed(42)
console.log(Channel.isChannel(channel)) // true
console.log(Channel.isChannel("not a channel")) // false
isChannel(args: IArgumentsargs[0]), <
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) N in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) B in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
(parameter) self: {
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 Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
name: Exclude<N, keyof OutElem>name: type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) N in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
f: (
a: NoInfer<OutElem>
) => Channel<
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>
a: NoInfer<OutElem>a: type NoInfer<T> = intrinsicMarker for non-inference type position
NoInfer<function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
interface Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<function (type parameter) B in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
options: | {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
| undefined
concurrency?: number | "unbounded" | undefinedconcurrency?: number | "unbounded" | undefined
readonly bufferSize?: number | undefinedbufferSize?: number | undefined
}
): interface Channel<out OutElem, out OutErr = never, out OutDone = void, in InElem = unknown, in InErr = unknown, in InDone = unknown, out Env = never>A Channel is a nexus of I/O operations, which supports both reading and
writing. A channel may read values of type InElem and write values of type
OutElem. When the channel finishes, it yields a value of type OutDone. A
channel may fail with a value of type OutErr.
Details
Channels are the foundation of Streams: both streams and sinks are built on
channels. Most users shouldn't have to use channels directly, as streams and
sinks are much more convenient and cover all common use cases. However, when
adding new stream and sink operators, or doing something highly specialized,
it may be useful to use channels directly.
Channels compose in a variety of ways:
- Piping: One channel can be piped to another channel, assuming the
input type of the second is the same as the output type of the first.
- Sequencing: The terminal value of one channel can be used to create
another channel, and both the first channel and the function that makes
the second channel can be composed into a channel.
- Concatenating: The output of one channel can be used to create other
channels, which are all concatenated together. The first channel and the
function that makes the other channels can be composed into a channel.
Example (Typing channels)
import type { Channel } from "effect"
// A channel that outputs numbers and requires no environment
type NumberChannel = Channel.Channel<number>
// A channel that outputs strings, can fail with Error, completes with boolean
type StringChannel = Channel.Channel<string, Error, boolean>
// A channel with all type parameters specified
type FullChannel = Channel.Channel<
string, // OutElem - output elements
Error, // OutErr - output errors
number, // OutDone - completion value
number, // InElem - input elements
string, // InErr - input errors
boolean, // InDone - input completion
{ db: string } // Env - required environment
>
Channel<
{ [function (type parameter) KK in function (type parameter) N in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) KK extends keyof function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) KK] : function (type parameter) B in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) OutDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InElem2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InErr2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) InDone2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env2 in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
function (type parameter) Env in <OutElem extends object, OutErr, OutDone, InElem, InErr, InDone, Env, N extends string, B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, name: Exclude<N, keyof OutElem>, f: (a: NoInfer<OutElem>) => Channel<B, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>, options?: {
readonly concurrency?: number | "unbounded" | undefined;
readonly bufferSize?: number | undefined;
}): Channel<{ [K in N | keyof OutElem]: K extends keyof OutElem ? OutElem[K] : B; }, OutErr2 | OutErr, OutDone, InElem & InElem2, InErr & InErr2, InDone & InDone2, Env2 | Env>
const flatMap: {
<
OutElem,
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>(
f: (
d: OutElem
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>,
options?: {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
): <
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
) => Channel<
OutElem1,
OutErr1 | OutErr,
OutDone,
InElem & InElem1,
InErr & InErr1,
InDone & InDone1,
Env1 | Env
>
<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env,
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>,
f: (
d: OutElem
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>,
options?: {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
): Channel<
OutElem1,
OutErr | OutErr1,
OutDone,
InElem & InElem1,
InErr & InErr1,
InDone & InDone1,
Env | Env1
>
}
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
(parameter) self: {
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; <…;
}
elem: OutElem extends objectelem) => const map: {
<OutElem, OutElem2>(
f: (o: OutElem, i: number) => OutElem2
): <
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
) => Channel<
OutElem2,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env,
OutElem2
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>,
f: (o: OutElem, i: number) => OutElem2
): Channel<
OutElem2,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
}
f: (
a: NoInfer<OutElem>
) => Channel<
B,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>
elem: OutElem extends objectelem), (b: Bb) => ({ ...elem: OutElem extends objectelem, [name: Exclude<N, keyof OutElem>name]: b: Bb } as any)),
options: | {
readonly concurrency?:
| number
| "unbounded"
| undefined
readonly bufferSize?: number | undefined
}
| undefined