<A, B>(f: (current: A) => [returnValue: B, newValue: A]): (
self: TxSubscriptionRef<A>
) => Effect.Effect<B>
<A, B>(
self: TxSubscriptionRef<A>,
f: (current: A) => [returnValue: B, newValue: A]
): Effect.Effect<B>Modifies the value of the TxSubscriptionRef using a function that returns both a result and the new value. The new value is published to all subscribers atomically.
When to use
Use to compute a separate return value and next TxSubscriptionRef state in
one transactional update.
Example (Modifying and returning a value)
import { Effect, TxSubscriptionRef } from "effect"
const program = Effect.gen(function*() {
const ref = yield* TxSubscriptionRef.make(10)
const result = yield* TxSubscriptionRef.modify(ref, (n) => [`was ${n}`, n + 1])
console.log(result) // "was 10"
console.log(yield* TxSubscriptionRef.get(ref)) // 11
})export const const modify: {
<A, B>(
f: (
current: A
) => [returnValue: B, newValue: A]
): (
self: TxSubscriptionRef<A>
) => Effect.Effect<B>
<A, B>(
self: TxSubscriptionRef<A>,
f: (
current: A
) => [returnValue: B, newValue: A]
): Effect.Effect<B>
}
Modifies the value of the TxSubscriptionRef using a function that returns both a
result and the new value. The new value is published to all subscribers atomically.
When to use
Use to compute a separate return value and next TxSubscriptionRef state in
one transactional update.
Example (Modifying and returning a value)
import { Effect, TxSubscriptionRef } from "effect"
const program = Effect.gen(function*() {
const ref = yield* TxSubscriptionRef.make(10)
const result = yield* TxSubscriptionRef.modify(ref, (n) => [`was ${n}`, n + 1])
console.log(result) // "was 10"
console.log(yield* TxSubscriptionRef.get(ref)) // 11
})
modify: {
<function (type parameter) A in <A, B>(f: (current: A) => [returnValue: B, newValue: A]): (self: TxSubscriptionRef<A>) => Effect.Effect<B>A, function (type parameter) B in <A, B>(f: (current: A) => [returnValue: B, newValue: A]): (self: TxSubscriptionRef<A>) => Effect.Effect<B>B>(
f: (
current: A
) => [returnValue: B, newValue: A]
current: Acurrent: function (type parameter) A in <A, B>(f: (current: A) => [returnValue: B, newValue: A]): (self: TxSubscriptionRef<A>) => Effect.Effect<B>A) => [BreturnValue: function (type parameter) B in <A, B>(f: (current: A) => [returnValue: B, newValue: A]): (self: TxSubscriptionRef<A>) => Effect.Effect<B>B, AnewValue: function (type parameter) A in <A, B>(f: (current: A) => [returnValue: B, newValue: A]): (self: TxSubscriptionRef<A>) => Effect.Effect<B>A]
): (self: TxSubscriptionRef<A>(parameter) self: {
ref: TxRef.TxRef<A>;
pubsub: TxPubSub.TxPubSub<A>;
toString: () => string;
toJSON: () => unknown;
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 TxSubscriptionRef<in out A>A TxSubscriptionRef is a transactional reference that allows subscribing to all
committed changes. Subscribers receive the current value followed by every subsequent
update via a transactional dequeue.
When to use
Use to store transactional state whose committed changes must be observable by
subscribers.
Example (Subscribing to transactional changes)
import { Effect, TxQueue, TxSubscriptionRef } from "effect"
const program = Effect.gen(function*() {
const ref = yield* TxSubscriptionRef.make(0)
yield* Effect.scoped(
Effect.gen(function*() {
const sub = yield* TxSubscriptionRef.changes(ref)
const initial = yield* TxQueue.take(sub)
console.log(initial) // 0
yield* TxSubscriptionRef.set(ref, 1)
const next = yield* TxQueue.take(sub)
console.log(next) // 1
})
)
})
TxSubscriptionRef<function (type parameter) A in <A, B>(f: (current: A) => [returnValue: B, newValue: A]): (self: TxSubscriptionRef<A>) => Effect.Effect<B>A>) => 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) B in <A, B>(f: (current: A) => [returnValue: B, newValue: A]): (self: TxSubscriptionRef<A>) => Effect.Effect<B>B>
<function (type parameter) A in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A, function (type parameter) B in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>B>(
self: TxSubscriptionRef<A>(parameter) self: {
ref: TxRef.TxRef<A>;
pubsub: TxPubSub.TxPubSub<A>;
toString: () => string;
toJSON: () => unknown;
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 TxSubscriptionRef<in out A>A TxSubscriptionRef is a transactional reference that allows subscribing to all
committed changes. Subscribers receive the current value followed by every subsequent
update via a transactional dequeue.
When to use
Use to store transactional state whose committed changes must be observable by
subscribers.
Example (Subscribing to transactional changes)
import { Effect, TxQueue, TxSubscriptionRef } from "effect"
const program = Effect.gen(function*() {
const ref = yield* TxSubscriptionRef.make(0)
yield* Effect.scoped(
Effect.gen(function*() {
const sub = yield* TxSubscriptionRef.changes(ref)
const initial = yield* TxQueue.take(sub)
console.log(initial) // 0
yield* TxSubscriptionRef.set(ref, 1)
const next = yield* TxQueue.take(sub)
console.log(next) // 1
})
)
})
TxSubscriptionRef<function (type parameter) A in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A>,
f: (
current: A
) => [returnValue: B, newValue: A]
current: Acurrent: function (type parameter) A in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A) => [BreturnValue: function (type parameter) B in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>B, AnewValue: function (type parameter) A in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A]
): 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) B in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>B>
} = dual<(...args: Array<any>) => any, <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]) => Effect.Effect<B>>(arity: 2, body: <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]) => Effect.Effect<B>): ((...args: Array<any>) => any) & (<A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]) => Effect.Effect<B>) (+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, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A, function (type parameter) B in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>B>(
self: TxSubscriptionRef<A>(parameter) self: {
ref: TxRef.TxRef<A>;
pubsub: TxPubSub.TxPubSub<A>;
toString: () => string;
toJSON: () => unknown;
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 TxSubscriptionRef<in out A>A TxSubscriptionRef is a transactional reference that allows subscribing to all
committed changes. Subscribers receive the current value followed by every subsequent
update via a transactional dequeue.
When to use
Use to store transactional state whose committed changes must be observable by
subscribers.
Example (Subscribing to transactional changes)
import { Effect, TxQueue, TxSubscriptionRef } from "effect"
const program = Effect.gen(function*() {
const ref = yield* TxSubscriptionRef.make(0)
yield* Effect.scoped(
Effect.gen(function*() {
const sub = yield* TxSubscriptionRef.changes(ref)
const initial = yield* TxQueue.take(sub)
console.log(initial) // 0
yield* TxSubscriptionRef.set(ref, 1)
const next = yield* TxQueue.take(sub)
console.log(next) // 1
})
)
})
TxSubscriptionRef<function (type parameter) A in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A>,
f: (
current: A
) => [returnValue: B, newValue: A]
current: Acurrent: function (type parameter) A in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A) => [BreturnValue: function (type parameter) B in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>B, AnewValue: function (type parameter) A in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>A]
): 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) B in <A, B>(self: TxSubscriptionRef<A>, f: (current: A) => [returnValue: B, newValue: A]): Effect.Effect<B>B> =>
import EffectEffect.const gen: {
<Eff extends Effect<any, any, any>, AEff>(
f: () => Generator<Eff, AEff, never>
): Effect<
AEff,
[Eff] extends [never]
? never
: [Eff] extends [
Effect<infer _A, infer E, infer _R>
]
? E
: never,
[Eff] extends [never]
? never
: [Eff] extends [
Effect<infer _A, infer _E, infer R>
]
? R
: never
>
<Self, Eff extends Effect<any, any, any>, AEff>(
options: { readonly self: Self },
f: (this: Self) => Generator<Eff, AEff, never>
): Effect<
AEff,
[Eff] extends [never]
? never
: [Eff] extends [
Effect<infer _A, infer E, infer _R>
]
? E
: never,
[Eff] extends [never]
? never
: [Eff] extends [
Effect<infer _A, infer _E, infer R>
]
? R
: never
>
}
const current: Acurrent = yield* import TxRefTxRef.const get: <A>(
self: TxRef<A>
) => Effect.Effect<A>
Reads the current value of the TxRef.
When to use
Use to read the current value of a TxRef.
Example (Reading transactional references)
import { Effect, TxRef } from "effect"
const program = Effect.gen(function*() {
const counter = yield* TxRef.make(42)
// Read the value within a transaction
const value = yield* Effect.tx(
TxRef.get(counter)
)
console.log(value) // 42
})
get(self: TxSubscriptionRef<A>(parameter) self: {
ref: TxRef.TxRef<A>;
pubsub: TxPubSub.TxPubSub<A>;
toString: () => string;
toJSON: () => unknown;
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; <…;
}
TxSubscriptionRef<A>.ref: TxRef.TxRef<A>(property) TxSubscriptionRef<A>.ref: {
version: number;
pending: Map<unknown, () => void>;
value: 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; <…;
}
const returnValue: BreturnValue, const newValue: AnewValue] = f: (
current: A
) => [returnValue: B, newValue: A]
const current: Acurrent)
yield* import TxRefTxRef.const set: {
<A>(value: A): (
self: TxRef<A>
) => Effect.Effect<void>
<A>(
self: TxRef<A>,
value: A
): Effect.Effect<void>
}
self: TxSubscriptionRef<A>(parameter) self: {
ref: TxRef.TxRef<A>;
pubsub: TxPubSub.TxPubSub<A>;
toString: () => string;
toJSON: () => unknown;
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; <…;
}
TxSubscriptionRef<A>.ref: TxRef.TxRef<A>(property) TxSubscriptionRef<A>.ref: {
version: number;
pending: Map<unknown, () => void>;
value: 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; <…;
}
const newValue: AnewValue)
yield* import TxPubSubTxPubSub.const publish: {
<A>(value: A): (
self: TxPubSub<A>
) => Effect.Effect<boolean>
<A>(
self: TxPubSub<A>,
value: A
): Effect.Effect<boolean>
}
self: TxSubscriptionRef<A>(parameter) self: {
ref: TxRef.TxRef<A>;
pubsub: TxPubSub.TxPubSub<A>;
toString: () => string;
toJSON: () => unknown;
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; <…;
}
TxSubscriptionRef<A>.pubsub: TxPubSub.TxPubSub<A>(property) TxSubscriptionRef<A>.pubsub: {
subscribersRef: TxRef.TxRef<Array<TxQueue.TxQueue<A>>>;
shutdownRef: TxRef.TxRef<boolean>;
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
toString: () => string;
toJSON: () => unknown;
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; <…;
}
const newValue: AnewValue)
return const returnValue: BreturnValue
}).Pipeable.pipe<Effect.Effect<B, never, never>, Effect.Effect<B, never, never>>(this: Effect.Effect<B, never, never>, ab: (_: Effect.Effect<B, never, never>) => Effect.Effect<B, never, never>): Effect.Effect<B, never, never> (+21 overloads)pipe(import EffectEffect.const tx: <A, E, R>(
effect: Effect<A, E, R>
) => Effect<A, E, Exclude<R, Transaction>>
Defines a transaction boundary. Transactions are "all or nothing" with respect to changes
made to transactional values (i.e. TxRef) that occur within the transaction body.
Details
If called inside an active transaction, tx composes with the current transaction and reuses
its journal and retry state instead of creating a nested boundary.
Effect transactions are optimistic with retry. A transaction is retried when
its body explicitly calls Effect.txRetry and any accessed transactional
value changes, or when any accessed transactional value changes because a
different transaction commits before the current one.
The outermost tx call creates the transaction boundary and commits or rolls back the full
composed transaction.
Example (Running a transaction)
import { Effect, TxRef } from "effect"
const program = Effect.gen(function*() {
const ref1 = yield* TxRef.make(0)
const ref2 = yield* TxRef.make(0)
// Nested tx calls compose into the same transaction
yield* Effect.tx(Effect.gen(function*() {
yield* TxRef.set(ref1, 10)
yield* Effect.tx(TxRef.set(ref2, 20))
const sum = (yield* TxRef.get(ref1)) + (yield* TxRef.get(ref2))
console.log(`Transaction sum: ${sum}`)
}))
console.log(`Final ref1: ${yield* TxRef.get(ref1)}`) // 10
console.log(`Final ref2: ${yield* TxRef.get(ref2)}`) // 20
})
tx)
)