(offset: number): <A, E, R>(
effect: Effect.Effect<A, E, R>
) => Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>
<A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<
A,
E,
Exclude<R, CurrentTimeZone>
>Provides the CurrentTimeZone to an effect, using an offset.
Example (Providing a fixed-offset time zone)
import { DateTime, Effect } from "effect"
Effect.gen(function*() {
const zone = yield* DateTime.CurrentTimeZone
console.log(DateTime.zoneToString(zone)) // "+03:00"
}).pipe(DateTime.withCurrentZoneOffset(3 * 60 * 60 * 1000))export const const withCurrentZoneOffset: {
(offset: number): <A, E, R>(
effect: Effect.Effect<A, E, R>
) => Effect.Effect<
A,
E,
Exclude<R, CurrentTimeZone>
>
<A, E, R>(
effect: Effect.Effect<A, E, R>,
offset: number
): Effect.Effect<
A,
E,
Exclude<R, CurrentTimeZone>
>
}
Provides the CurrentTimeZone to an effect, using an offset.
Example (Providing a fixed-offset time zone)
import { DateTime, Effect } from "effect"
Effect.gen(function*() {
const zone = yield* DateTime.CurrentTimeZone
console.log(DateTime.zoneToString(zone)) // "+03:00"
}).pipe(DateTime.withCurrentZoneOffset(3 * 60 * 60 * 1000))
withCurrentZoneOffset: {
(offset: numberoffset: number): <function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R>(
effect: Effect.Effect<A, E, R>(parameter) effect: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import EffectEffect.interface Effect<out A, out E = never, out R = never>The Effect interface defines a value that lazily describes a workflow or
job. The workflow requires some context R, and may fail with an error of
type E, or succeed with a value of type A.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
Effect values model resourceful interaction with the outside world,
including synchronous, asynchronous, concurrent, and parallel interaction.
They use a fiber-based concurrency model, with built-in support for
scheduling, fine-grained interruption, structured concurrency, and high
scalability.
To run an Effect value, you need a Runtime, which is a type that is
capable of executing Effect values.
Effect<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R>
) => import EffectEffect.interface Effect<out A, out E = never, out R = never>The Effect interface defines a value that lazily describes a workflow or
job. The workflow requires some context R, and may fail with an error of
type E, or succeed with a value of type A.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
Effect values model resourceful interaction with the outside world,
including synchronous, asynchronous, concurrent, and parallel interaction.
They use a fiber-based concurrency model, with built-in support for
scheduling, fine-grained interruption, structured concurrency, and high
scalability.
To run an Effect value, you need a Runtime, which is a type that is
capable of executing Effect values.
Effect<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R, class CurrentTimeZoneclass CurrentTimeZone {
Service: Service;
key: Identifier;
}
Context service that supplies the ambient TimeZone for APIs that work in
the current zone, such as DateTime.setZoneCurrent and
DateTime.nowInCurrentZone.
Details
Provide it with DateTime.withCurrentZone, one of the withCurrentZone*
helpers, or one of the layerCurrentZone* layers.
Example (Accessing the current time zone service)
import { DateTime, Effect } from "effect"
const program = Effect.gen(function*() {
// Access the current time zone service
const zone = yield* DateTime.CurrentTimeZone
console.log(DateTime.zoneToString(zone))
})
// Provide a time zone
const layer = DateTime.layerCurrentZoneNamed("Europe/London")
Effect.provide(program, layer)
CurrentTimeZone>>
<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R>(effect: Effect.Effect<A, E, R>(parameter) effect: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import EffectEffect.interface Effect<out A, out E = never, out R = never>The Effect interface defines a value that lazily describes a workflow or
job. The workflow requires some context R, and may fail with an error of
type E, or succeed with a value of type A.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
Effect values model resourceful interaction with the outside world,
including synchronous, asynchronous, concurrent, and parallel interaction.
They use a fiber-based concurrency model, with built-in support for
scheduling, fine-grained interruption, structured concurrency, and high
scalability.
To run an Effect value, you need a Runtime, which is a type that is
capable of executing Effect values.
Effect<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R>, offset: numberoffset: number): import EffectEffect.interface Effect<out A, out E = never, out R = never>The Effect interface defines a value that lazily describes a workflow or
job. The workflow requires some context R, and may fail with an error of
type E, or succeed with a value of type A.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
Effect values model resourceful interaction with the outside world,
including synchronous, asynchronous, concurrent, and parallel interaction.
They use a fiber-based concurrency model, with built-in support for
scheduling, fine-grained interruption, structured concurrency, and high
scalability.
To run an Effect value, you need a Runtime, which is a type that is
capable of executing Effect values.
Effect<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R, class CurrentTimeZoneclass CurrentTimeZone {
Service: Service;
key: Identifier;
}
Context service that supplies the ambient TimeZone for APIs that work in
the current zone, such as DateTime.setZoneCurrent and
DateTime.nowInCurrentZone.
Details
Provide it with DateTime.withCurrentZone, one of the withCurrentZone*
helpers, or one of the layerCurrentZone* layers.
Example (Accessing the current time zone service)
import { DateTime, Effect } from "effect"
const program = Effect.gen(function*() {
// Access the current time zone service
const zone = yield* DateTime.CurrentTimeZone
console.log(DateTime.zoneToString(zone))
})
// Provide a time zone
const layer = DateTime.layerCurrentZoneNamed("Europe/London")
Effect.provide(program, layer)
CurrentTimeZone>>
} = dual<(...args: Array<any>) => any, <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number) => Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>>(arity: 2, body: <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number) => Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>): ((...args: Array<any>) => any) & (<A, E, R>(effect: Effect.Effect<A, E, R>, offset: number) => Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>) (+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(
2,
<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R>(effect: Effect.Effect<A, E, R>(parameter) effect: {
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
toString: () => string;
toJSON: () => unknown;
}
import EffectEffect.interface Effect<out A, out E = never, out R = never>The Effect interface defines a value that lazily describes a workflow or
job. The workflow requires some context R, and may fail with an error of
type E, or succeed with a value of type A.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
Effect values model resourceful interaction with the outside world,
including synchronous, asynchronous, concurrent, and parallel interaction.
They use a fiber-based concurrency model, with built-in support for
scheduling, fine-grained interruption, structured concurrency, and high
scalability.
To run an Effect value, you need a Runtime, which is a type that is
capable of executing Effect values.
Effect<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R>, offset: numberoffset: number): import EffectEffect.interface Effect<out A, out E = never, out R = never>The Effect interface defines a value that lazily describes a workflow or
job. The workflow requires some context R, and may fail with an error of
type E, or succeed with a value of type A.
When to use
Use when you need to represent a lazy, composable workflow that can require
services, fail with a typed error, or succeed with a typed value.
Details
Effect values model resourceful interaction with the outside world,
including synchronous, asynchronous, concurrent, and parallel interaction.
They use a fiber-based concurrency model, with built-in support for
scheduling, fine-grained interruption, structured concurrency, and high
scalability.
To run an Effect value, you need a Runtime, which is a type that is
capable of executing Effect values.
Effect<function (type parameter) A in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>A, function (type parameter) E in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>E, type Exclude<T, U> = T extends U
? never
: T
Exclude from T those types that are assignable to U
Exclude<function (type parameter) R in <A, E, R>(effect: Effect.Effect<A, E, R>, offset: number): Effect.Effect<A, E, Exclude<R, CurrentTimeZone>>R, class CurrentTimeZoneclass CurrentTimeZone {
Service: Service;
key: Identifier;
}
Context service that supplies the ambient TimeZone for APIs that work in
the current zone, such as DateTime.setZoneCurrent and
DateTime.nowInCurrentZone.
Details
Provide it with DateTime.withCurrentZone, one of the withCurrentZone*
helpers, or one of the layerCurrentZone* layers.
Example (Accessing the current time zone service)
import { DateTime, Effect } from "effect"
const program = Effect.gen(function*() {
// Access the current time zone service
const zone = yield* DateTime.CurrentTimeZone
console.log(DateTime.zoneToString(zone))
})
// Provide a time zone
const layer = DateTime.layerCurrentZoneNamed("Europe/London")
Effect.provide(program, layer)
CurrentTimeZone>> =>
import EffectEffect.const provideService: {
<I, S>(service: Context.Key<I, S>): {
(implementation: S): <A, E, R>(
self: Effect<A, E, R>
) => Effect<A, E, Exclude<R, I>>
<A, E, R>(
self: Effect<A, E, R>,
implementation: S
): Effect<A, E, Exclude<R, I>>
}
<I, S>(
service: Context.Key<I, S>,
implementation: S
): <A, E, R>(
self: Effect<A, E, R>
) => Effect<A, E, Exclude<R, I>>
<A, E, R, I, S>(
self: Effect<A, E, R>,
service: Context.Key<I, S>,
implementation: S
): Effect<A, E, Exclude<R, I>>
}
effect: Effect.Effect<A, E, R>(parameter) effect: {
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;
}
class CurrentTimeZoneclass CurrentTimeZone {
key: Identifier;
of: (this: void, self: TimeZone) => TimeZone;
context: (self: TimeZone) => Context.Context<CurrentTimeZone>;
use: (f: (service: TimeZone) => Effect.Effect<A, E, R>) => Effect.Effect<A, E, CurrentTimeZone | R>;
useSync: (f: (service: TimeZone) => A) => Effect.Effect<A, never, CurrentTimeZone>;
Identifier: Identifier;
Service: Shape;
stack: string | undefined;
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;
}
Context service that supplies the ambient TimeZone for APIs that work in
the current zone, such as DateTime.setZoneCurrent and
DateTime.nowInCurrentZone.
Details
Provide it with DateTime.withCurrentZone, one of the withCurrentZone*
helpers, or one of the layerCurrentZone* layers.
Example (Accessing the current time zone service)
import { DateTime, Effect } from "effect"
const program = Effect.gen(function*() {
// Access the current time zone service
const zone = yield* DateTime.CurrentTimeZone
console.log(DateTime.zoneToString(zone))
})
// Provide a time zone
const layer = DateTime.layerCurrentZoneNamed("Europe/London")
Effect.provide(program, layer)
CurrentTimeZone, const zoneMakeOffset: (
offset: number
) => TimeZone.Offset
Create a fixed offset time zone.
Details
The offset is specified in milliseconds from UTC. Positive values are
ahead of UTC, negative values are behind UTC.
Example (Creating fixed-offset time zones)
import { DateTime } from "effect"
// Create a time zone with +3 hours offset
const zone = DateTime.zoneMakeOffset(3 * 60 * 60 * 1000)
const dt = DateTime.makeZonedUnsafe("2024-01-01T12:00:00Z", {
timeZone: zone
})
zoneMakeOffset(offset: numberoffset))
)