<
OutErr,
EB,
X,
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1,
OutElem2 = Types.unassigned,
OutErr2 = never,
OutDone2 = never,
InElem2 = unknown,
InErr2 = unknown,
InDone2 = unknown,
Env2 = never
>(
filter: Filter.Filter<OutErr, EB, X>,
f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>,
orElse?:
| ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
): <OutElem, OutDone, InElem, InErr, InDone, Env>(
self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>
) => Channel<
OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>,
OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never),
OutDone | OutDone1 | OutDone2,
InElem & InElem1 & InElem2,
InErr & InErr1 & InErr2,
InDone & InDone1 & InDone2,
Env | Env1 | Env2
>
<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env,
EB,
X,
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1,
OutElem2 = Types.unassigned,
OutErr2 = never,
OutDone2 = never,
InElem2 = unknown,
InErr2 = unknown,
InDone2 = unknown,
Env2 = never
>(
self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>,
filter: Filter.Filter<OutErr, EB, X>,
f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>,
orElse?:
| ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
): Channel<
OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>,
OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never),
OutDone | OutDone1 | OutDone2,
InElem & InElem1 & InElem2,
InErr & InErr1 & InErr2,
InDone & InDone1 & InDone2,
Env | Env1 | Env2
>Recovers from typed channel errors selected by a Filter.
When to use
Use to recover from channel errors with a reusable Filter when matching
can also narrow or transform the error before choosing the recovery channel.
Details
Successful filter results are handled by the recovery function. Failed
filter results are handled by orElse when provided. Without orElse,
failed filter results are re-failed.
Source effect/Channel.ts:4767146 lines
export const const catchFilter: {
<
OutErr,
EB,
X,
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1,
OutElem2 = Types.unassigned,
OutErr2 = never,
OutDone2 = never,
InElem2 = unknown,
InErr2 = unknown,
InDone2 = unknown,
Env2 = never
>(
filter: Filter.Filter<OutErr, EB, X>,
f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>,
orElse?:
| ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
): <
OutElem,
OutDone,
InElem,
InErr,
InDone,
Env
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
) => Channel<
| OutElem
| OutElem1
| Exclude<OutElem2, Types.unassigned>,
| OutErr1
| OutErr2
| (OutElem2 extends Types.unassigned
? X
: never),
OutDone | OutDone1 | OutDone2,
InElem & InElem1 & InElem2,
InErr & InErr1 & InErr2,
InDone & InDone1 & InDone2,
Env | Env1 | Env2
>
<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env,
EB,
X,
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1,
OutElem2 = Types.unassigned,
OutErr2 = never,
OutDone2 = never,
InElem2 = unknown,
InErr2 = unknown,
InDone2 = unknown,
Env2 = never
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>,
filter: Filter.Filter<OutErr, EB, X>,
f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>,
orElse?:
| ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
): Channel<
| OutElem
| OutElem1
| Exclude<OutElem2, Types.unassigned>,
| OutErr1
| OutErr2
| (OutElem2 extends Types.unassigned
? X
: never),
OutDone | OutDone1 | OutDone2,
InElem & InElem1 & InElem2,
InErr & InErr1 & InErr2,
InDone & InDone1 & InDone2,
Env | Env1 | Env2
>
}
Recovers from typed channel errors selected by a Filter.
When to use
Use to recover from channel errors with a reusable Filter when matching
can also narrow or transform the error before choosing the recovery channel.
Details
Successful filter results are handled by the recovery function. Failed
filter results are handled by orElse when provided. Without orElse,
failed filter results are re-failed.
catchFilter: {
<
function (type parameter) OutErr in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr,
function (type parameter) EB in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB,
function (type parameter) X in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X,
function (type parameter) OutElem1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1,
function (type parameter) OutErr1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1,
function (type parameter) OutDone1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1,
function (type parameter) InElem1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1,
function (type parameter) InErr1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1,
function (type parameter) InDone1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1,
function (type parameter) Env1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1,
function (type parameter) OutElem2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2 = import TypesTypes.unassigned,
function (type parameter) OutErr2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2 = never,
function (type parameter) OutDone2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2 = never,
function (type parameter) InElem2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2 = unknown,
function (type parameter) InErr2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2 = unknown,
function (type parameter) InDone2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2 = unknown,
function (type parameter) Env2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2 = never
>(
filter: Filter.Filter<OutErr, EB, X>filter: import FilterFilter.interface Filter<in Input, out Pass = Input, out Fail = Input>Represents a filter function that can transform inputs to outputs or filter them out.
Details
A filter takes an input value and either returns a boxed pass value or the
special fail type to indicate the value should be filtered out.
Example (Defining a positive number filter)
import { Filter, Result } from "effect"
// A filter that only passes positive numbers
const positiveFilter: Filter.Filter<number> = (n) => n > 0 ? Result.succeed(n) : Result.fail(n)
console.log(positiveFilter(5)) // Result.succeed(5)
console.log(positiveFilter(-3)) // Result.fail(-3)
Filter<function (type parameter) OutErr in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr, function (type parameter) EB in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB, function (type parameter) X in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X>,
f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>
failure: EBfailure: function (type parameter) EB in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB) => 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) OutElem1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1, function (type parameter) OutErr1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1, function (type parameter) OutDone1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1, function (type parameter) InElem1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1, function (type parameter) InErr1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1, function (type parameter) InDone1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1, function (type parameter) Env1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1>,
orElse: | ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
failure: Xfailure: function (type parameter) X in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X
) => 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) OutElem2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2, function (type parameter) OutErr2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2, function (type parameter) OutDone2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2, function (type parameter) InElem2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2, function (type parameter) InErr2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2, function (type parameter) InDone2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2, function (type parameter) Env2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2>)
| undefined
): <
function (type parameter) OutElem in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem,
function (type parameter) OutDone in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone,
function (type parameter) InElem in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem,
function (type parameter) InErr in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr,
function (type parameter) InDone in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone,
function (type parameter) Env in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | 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, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem, function (type parameter) OutErr in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr, function (type parameter) OutDone in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone, function (type parameter) InElem in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem, function (type parameter) InErr in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr, function (type parameter) InDone in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone, function (type parameter) Env in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | 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) OutElem in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem | function (type parameter) OutElem1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1 | type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) OutElem2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2, import TypesTypes.unassigned>,
function (type parameter) OutErr1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1 | function (type parameter) OutErr2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2 | (function (type parameter) OutElem2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2 extends import TypesTypes.unassigned ? function (type parameter) X in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X : never),
function (type parameter) OutDone in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone | function (type parameter) OutDone1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1 | function (type parameter) OutDone2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2,
function (type parameter) InElem in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem & function (type parameter) InElem1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1 & function (type parameter) InElem2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2,
function (type parameter) InErr in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr & function (type parameter) InErr1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1 & function (type parameter) InErr2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2,
function (type parameter) InDone in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone & function (type parameter) InDone1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1 & function (type parameter) InDone2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2,
function (type parameter) Env in <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env | function (type parameter) Env1 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1 | function (type parameter) Env2 in <OutErr, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): <OutElem, OutDone, InElem, InErr, InDone, Env>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>) => Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2
>
<
function (type parameter) OutElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem,
function (type parameter) OutErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr,
function (type parameter) OutDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone,
function (type parameter) InElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem,
function (type parameter) InErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr,
function (type parameter) InDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone,
function (type parameter) Env in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env,
function (type parameter) EB in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB,
function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X,
function (type parameter) OutElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1,
function (type parameter) OutErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1,
function (type parameter) OutDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1,
function (type parameter) InElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1,
function (type parameter) InErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1,
function (type parameter) InDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1,
function (type parameter) Env1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1,
function (type parameter) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2 = import TypesTypes.unassigned,
function (type parameter) OutErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2 = never,
function (type parameter) OutDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2 = never,
function (type parameter) InElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2 = unknown,
function (type parameter) InErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2 = unknown,
function (type parameter) InDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2 = unknown,
function (type parameter) Env2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2 = never
>(
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, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem, function (type parameter) OutErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr, function (type parameter) OutDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone, function (type parameter) InElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem, function (type parameter) InErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr, function (type parameter) InDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone, function (type parameter) Env in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env>,
filter: Filter.Filter<OutErr, EB, X>filter: import FilterFilter.interface Filter<in Input, out Pass = Input, out Fail = Input>Represents a filter function that can transform inputs to outputs or filter them out.
Details
A filter takes an input value and either returns a boxed pass value or the
special fail type to indicate the value should be filtered out.
Example (Defining a positive number filter)
import { Filter, Result } from "effect"
// A filter that only passes positive numbers
const positiveFilter: Filter.Filter<number> = (n) => n > 0 ? Result.succeed(n) : Result.fail(n)
console.log(positiveFilter(5)) // Result.succeed(5)
console.log(positiveFilter(-3)) // Result.fail(-3)
Filter<function (type parameter) OutErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr, function (type parameter) EB in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB, function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X>,
f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>
failure: EBfailure: function (type parameter) EB in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB) => 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) OutElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1, function (type parameter) OutErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1, function (type parameter) OutDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1, function (type parameter) InElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1, function (type parameter) InErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1, function (type parameter) InDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1, function (type parameter) Env1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1>,
orElse: | ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
failure: Xfailure: function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X
) => 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) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2, function (type parameter) OutErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2, function (type parameter) OutDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2, function (type parameter) InElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2, function (type parameter) InErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2, function (type parameter) InDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2, function (type parameter) Env2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2>)
| 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) OutElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem | function (type parameter) OutElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1 | type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2, import TypesTypes.unassigned>,
function (type parameter) OutErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1 | function (type parameter) OutErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2 | (function (type parameter) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2 extends import TypesTypes.unassigned ? function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X : never),
function (type parameter) OutDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone | function (type parameter) OutDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1 | function (type parameter) OutDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2,
function (type parameter) InElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem & function (type parameter) InElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1 & function (type parameter) InElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2,
function (type parameter) InErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr & function (type parameter) InErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1 & function (type parameter) InErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2,
function (type parameter) InDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone & function (type parameter) InDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1 & function (type parameter) InDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2,
function (type parameter) Env in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env | function (type parameter) Env1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1 | function (type parameter) Env2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = Types.unassigned, OutErr2 = never, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | Exclude<OutElem2, Types.unassigned>, OutErr1 | OutErr2 | (OutElem2 extends Types.unassigned ? X : never), OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2
>
} = dual<(...args: Array<any>) => any, <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined) => Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>>(isDataFirst: (args: IArguments) => boolean, body: <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined) => Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>): ((...args: Array<any>) => any) & (<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined) => Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>) (+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, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem,
function (type parameter) OutErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr,
function (type parameter) OutDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone,
function (type parameter) InElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem,
function (type parameter) InErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr,
function (type parameter) InDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone,
function (type parameter) Env in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env,
function (type parameter) EB in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB,
function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X,
function (type parameter) OutElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1,
function (type parameter) OutErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1,
function (type parameter) OutDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1,
function (type parameter) InElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1,
function (type parameter) InErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1,
function (type parameter) InDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1,
function (type parameter) Env1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1,
function (type parameter) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2 = never,
function (type parameter) OutErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2 = function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X,
function (type parameter) OutDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2 = never,
function (type parameter) InElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2 = unknown,
function (type parameter) InErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2 = unknown,
function (type parameter) InDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2 = unknown,
function (type parameter) Env2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2 = never
>(
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, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem, function (type parameter) OutErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr, function (type parameter) OutDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone, function (type parameter) InElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem, function (type parameter) InErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr, function (type parameter) InDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone, function (type parameter) Env in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env>,
filter: Filter.Filter<OutErr, EB, X>filter: import FilterFilter.interface Filter<in Input, out Pass = Input, out Fail = Input>Represents a filter function that can transform inputs to outputs or filter them out.
Details
A filter takes an input value and either returns a boxed pass value or the
special fail type to indicate the value should be filtered out.
Example (Defining a positive number filter)
import { Filter, Result } from "effect"
// A filter that only passes positive numbers
const positiveFilter: Filter.Filter<number> = (n) => n > 0 ? Result.succeed(n) : Result.fail(n)
console.log(positiveFilter(5)) // Result.succeed(5)
console.log(positiveFilter(-3)) // Result.fail(-3)
Filter<function (type parameter) OutErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr, function (type parameter) EB in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB, function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X>,
f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>
failure: EBfailure: function (type parameter) EB in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>EB) => 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) OutElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1, function (type parameter) OutErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1, function (type parameter) OutDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1, function (type parameter) InElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1, function (type parameter) InErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1, function (type parameter) InDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1, function (type parameter) Env1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1>,
orElse: | ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
failure: Xfailure: function (type parameter) X in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>X
) => 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) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2, function (type parameter) OutErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2, function (type parameter) OutDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2, function (type parameter) InElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2, function (type parameter) InErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2, function (type parameter) InDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2, function (type parameter) Env2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2>)
| 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) OutElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem | function (type parameter) OutElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1 | function (type parameter) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2,
function (type parameter) OutErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1 | function (type parameter) OutErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2,
function (type parameter) OutDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone | function (type parameter) OutDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1 | function (type parameter) OutDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2,
function (type parameter) InElem in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem & function (type parameter) InElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1 & function (type parameter) InElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2,
function (type parameter) InErr in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr & function (type parameter) InErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1 & function (type parameter) InErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2,
function (type parameter) InDone in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone & function (type parameter) InDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1 & function (type parameter) InDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2,
function (type parameter) Env in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env | function (type parameter) Env1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1 | function (type parameter) Env2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2
> =>
const catch_: {
<
OutErr,
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>(
f: (
d: OutErr
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>
): <
OutElem,
OutDone,
InElem,
InErr,
InDone,
Env
>(
self: Channel<
OutElem,
OutErr,
OutDone,
InElem,
InErr,
InDone,
Env
>
) => Channel<
OutElem | OutElem1,
OutErr1,
OutDone | OutDone1,
InElem & InElem1,
InErr & InErr1,
InDone & InDone1,
Env | Env1
>
<
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: OutErr
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>
): Channel<
OutElem | OutElem1,
OutErr1,
OutDone | OutDone1,
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; <…;
}
err: OutErrerr): 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) OutElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem1 | function (type parameter) OutElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutElem2,
function (type parameter) OutErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr1 | function (type parameter) OutErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutErr2,
function (type parameter) OutDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone1 | function (type parameter) OutDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>OutDone2,
function (type parameter) InElem1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem1 & function (type parameter) InElem2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InElem2,
function (type parameter) InErr1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr1 & function (type parameter) InErr2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InErr2,
function (type parameter) InDone1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone1 & function (type parameter) InDone2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>InDone2,
function (type parameter) Env1 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env1 | function (type parameter) Env2 in <OutElem, OutErr, OutDone, InElem, InErr, InDone, Env, EB, X, OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1, OutElem2 = never, OutErr2 = X, OutDone2 = never, InElem2 = unknown, InErr2 = unknown, InDone2 = unknown, Env2 = never>(self: Channel<OutElem, OutErr, OutDone, InElem, InErr, InDone, Env>, filter: Filter.Filter<OutErr, EB, X>, f: (failure: EB) => Channel<OutElem1, OutErr1, OutDone1, InElem1, InErr1, InDone1, Env1>, orElse?: ((failure: X) => Channel<OutElem2, OutErr2, OutDone2, InElem2, InErr2, InDone2, Env2>) | undefined): Channel<OutElem | OutElem1 | OutElem2, OutErr1 | OutErr2, OutDone | OutDone1 | OutDone2, InElem & InElem1 & InElem2, InErr & InErr1 & InErr2, InDone & InDone1 & InDone2, Env | Env1 | Env2>Env2
> => {
const const result: Result.Result<EB, X>result = filter: Filter.Filter<OutErr, EB, X>filter(err: OutErrerr)
return import ResultResult.const isFailure: <A, E>(
self: Result<A, E>
) => self is Failure<A, E>
Checks whether a Result is a Failure.
When to use
Use to narrow a known Result to the Failure variant.
Details
- Acts as a TypeScript type guard, narrowing to
Failure<A, E>
- After narrowing, you can access
.failure to read the error value
Example (Narrowing to failure)
import { Result } from "effect"
const result = Result.fail("oops")
if (Result.isFailure(result)) {
console.log(result.failure)
// Output: "oops"
}
isFailure(const result: Result.Result<EB, X>result)
? orElse: | ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
orElse: | ((
failure: X
) => Channel<
OutElem2,
OutErr2,
OutDone2,
InElem2,
InErr2,
InDone2,
Env2
>)
| undefined
const result: Result.Failure<EB, X>const result: {
_tag: "Failure";
_op: "Failure";
failure: E;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
Failure<EB, X>.failure: Xfailure)
: const fail: <E>(
error: E
) => Channel<never, E, never>
Constructs a channel that fails immediately with the specified error.
Example (Failing with an error)
import { Channel } from "effect"
// Create a channel that fails with a string error
const failedChannel = Channel.fail("Something went wrong")
// Create a channel that fails with a custom error
class CustomError extends Error {
constructor(message: string) {
super(message)
this.name = "CustomError"
}
}
const customErrorChannel = Channel.fail(new CustomError("Custom error"))
// Use in error handling by piping to another channel
const channelWithFallback = Channel.concatWith(
failedChannel,
() => Channel.succeed("fallback value")
)
fail(const result: Result.Failure<EB, X>const result: {
_tag: "Failure";
_op: "Failure";
failure: E;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
Failure<EB, X>.failure: Xfailure as any) as any
: f: (
failure: EB
) => Channel<
OutElem1,
OutErr1,
OutDone1,
InElem1,
InErr1,
InDone1,
Env1
>
const result: Result.Success<EB, X>const result: {
_tag: "Success";
_op: "Success";
success: A;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
Success<EB, X>.success: EBsuccess)
}
))Referenced by 2 symbols