<E>(cause: Cause.Cause<E>): <A>(
self: TxEnqueue<A, E>
) => Effect.Effect<boolean>
<A, E>(
self: TxEnqueue<A, E>,
cause: Cause.Cause<E>
): Effect.Effect<boolean>Completes the queue with the specified cause.
Details
If the queue is empty, it transitions directly to done. If it still contains items, it enters the closing state so buffered items can be drained before the cause is observed. Returns false if the queue was already closing or done.
Example (Failing queues with causes)
import { Cause, Effect, TxQueue } from "effect"
const program = Effect.gen(function*() {
const queue = yield* TxQueue.bounded<number>(10)
// Complete with specific cause
const cause = Cause.interrupt()
const result = yield* TxQueue.failCause(queue, cause)
console.log(result) // true
})export const const failCause: {
<E>(cause: Cause.Cause<E>): <A>(
self: TxEnqueue<A, E>
) => Effect.Effect<boolean>
<A, E>(
self: TxEnqueue<A, E>,
cause: Cause.Cause<E>
): Effect.Effect<boolean>
}
Completes the queue with the specified cause.
Details
If the queue is empty, it transitions directly to done. If it still contains items, it enters the closing state so buffered items can be drained before the cause is observed. Returns false if the queue was already closing or done.
Example (Failing queues with causes)
import { Cause, Effect, TxQueue } from "effect"
const program = Effect.gen(function*() {
const queue = yield* TxQueue.bounded<number>(10)
// Complete with specific cause
const cause = Cause.interrupt()
const result = yield* TxQueue.failCause(queue, cause)
console.log(result) // true
})
failCause: {
<function (type parameter) E in <E>(cause: Cause.Cause<E>): <A>(self: TxEnqueue<A, E>) => Effect.Effect<boolean>E>(cause: Cause.Cause<E>(parameter) cause: {
reasons: ReadonlyArray<Reason<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;
}
import CauseCause.interface Cause<out E>A structured representation of how an Effect failed.
When to use
Use to preserve the full structured failure information for an effect instead
of collapsing it to a single error value.
Details
Access the individual failure entries through the reasons array, then
narrow each entry with
isFailReason
,
isDieReason
, or
- Use
hasFails
/
hasDies
/
hasInterrupts
to test
for the presence of specific reason kinds without iterating.
- Use
findError
/
findDefect
to extract the first value
of a given kind.
- Use
combine
to merge two causes.
Cause implements Equal — two causes with the same reasons (by value)
compare as equal.
Example (Creating and inspecting a cause)
import { Cause } from "effect"
const cause = Cause.fail("Something went wrong")
console.log(cause.reasons.length) // 1
console.log(Cause.isFailReason(cause.reasons[0])) // true
Companion namespace for the Cause interface.
Cause<function (type parameter) E in <E>(cause: Cause.Cause<E>): <A>(self: TxEnqueue<A, E>) => Effect.Effect<boolean>E>): <function (type parameter) A in <A>(self: TxEnqueue<A, E>): Effect.Effect<boolean>A>(self: TxEnqueue<A, E>(parameter) self: {
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
items: TxChunk.TxChunk<any>;
stateRef: TxRef.TxRef<State<any, any>>;
toString: () => string;
toJSON: () => unknown;
}
interface TxEnqueue<in A, in E = never>Namespace containing type definitions for TxEnqueue variance annotations.
A TxEnqueue represents the write-only interface of a transactional queue, providing
operations for adding elements (enqueue operations) and inspecting queue state.
Example (Offering values through enqueue handles)
import { Effect, TxQueue } from "effect"
import type { Cause } from "effect"
const program = Effect.gen(function*() {
// Queue without error channel
const queue = yield* TxQueue.bounded<number>(10)
const accepted = yield* TxQueue.offer(queue, 42)
// Queue with error channel for completion signaling
const faultTolerantQueue = yield* TxQueue.bounded<number, string>(10)
yield* TxQueue.offerAll(faultTolerantQueue, [1, 2, 3])
yield* TxQueue.fail(faultTolerantQueue, "processing complete")
// Works with Done for clean completion
const completableQueue = yield* TxQueue.bounded<
string,
Cause.Done
>(5)
yield* TxQueue.offer(completableQueue, "task")
yield* TxQueue.end(completableQueue)
})
TxEnqueue<function (type parameter) A in <A>(self: TxEnqueue<A, E>): Effect.Effect<boolean>A, function (type parameter) E in <E>(cause: Cause.Cause<E>): <A>(self: TxEnqueue<A, E>) => Effect.Effect<boolean>E>) => 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<boolean>
<function (type parameter) A in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>A, function (type parameter) E in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>E>(self: TxEnqueue<A, E>(parameter) self: {
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
items: TxChunk.TxChunk<any>;
stateRef: TxRef.TxRef<State<any, any>>;
toString: () => string;
toJSON: () => unknown;
}
interface TxEnqueue<in A, in E = never>Namespace containing type definitions for TxEnqueue variance annotations.
A TxEnqueue represents the write-only interface of a transactional queue, providing
operations for adding elements (enqueue operations) and inspecting queue state.
Example (Offering values through enqueue handles)
import { Effect, TxQueue } from "effect"
import type { Cause } from "effect"
const program = Effect.gen(function*() {
// Queue without error channel
const queue = yield* TxQueue.bounded<number>(10)
const accepted = yield* TxQueue.offer(queue, 42)
// Queue with error channel for completion signaling
const faultTolerantQueue = yield* TxQueue.bounded<number, string>(10)
yield* TxQueue.offerAll(faultTolerantQueue, [1, 2, 3])
yield* TxQueue.fail(faultTolerantQueue, "processing complete")
// Works with Done for clean completion
const completableQueue = yield* TxQueue.bounded<
string,
Cause.Done
>(5)
yield* TxQueue.offer(completableQueue, "task")
yield* TxQueue.end(completableQueue)
})
TxEnqueue<function (type parameter) A in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>A, function (type parameter) E in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>E>, cause: Cause.Cause<E>(parameter) cause: {
reasons: ReadonlyArray<Reason<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;
}
import CauseCause.interface Cause<out E>A structured representation of how an Effect failed.
When to use
Use to preserve the full structured failure information for an effect instead
of collapsing it to a single error value.
Details
Access the individual failure entries through the reasons array, then
narrow each entry with
isFailReason
,
isDieReason
, or
- Use
hasFails
/
hasDies
/
hasInterrupts
to test
for the presence of specific reason kinds without iterating.
- Use
findError
/
findDefect
to extract the first value
of a given kind.
- Use
combine
to merge two causes.
Cause implements Equal — two causes with the same reasons (by value)
compare as equal.
Example (Creating and inspecting a cause)
import { Cause } from "effect"
const cause = Cause.fail("Something went wrong")
console.log(cause.reasons.length) // 1
console.log(Cause.isFailReason(cause.reasons[0])) // true
Companion namespace for the Cause interface.
Cause<function (type parameter) E in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>E>): 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<boolean>
} = dual<(...args: Array<any>) => any, <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>) => Effect.Effect<boolean>>(arity: 2, body: <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>) => Effect.Effect<boolean>): ((...args: Array<any>) => any) & (<A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>) => Effect.Effect<boolean>) (+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>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>A, function (type parameter) E in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>E>(self: TxEnqueue<A, E>(parameter) self: {
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
items: TxChunk.TxChunk<any>;
stateRef: TxRef.TxRef<State<any, any>>;
toString: () => string;
toJSON: () => unknown;
}
interface TxEnqueue<in A, in E = never>Namespace containing type definitions for TxEnqueue variance annotations.
A TxEnqueue represents the write-only interface of a transactional queue, providing
operations for adding elements (enqueue operations) and inspecting queue state.
Example (Offering values through enqueue handles)
import { Effect, TxQueue } from "effect"
import type { Cause } from "effect"
const program = Effect.gen(function*() {
// Queue without error channel
const queue = yield* TxQueue.bounded<number>(10)
const accepted = yield* TxQueue.offer(queue, 42)
// Queue with error channel for completion signaling
const faultTolerantQueue = yield* TxQueue.bounded<number, string>(10)
yield* TxQueue.offerAll(faultTolerantQueue, [1, 2, 3])
yield* TxQueue.fail(faultTolerantQueue, "processing complete")
// Works with Done for clean completion
const completableQueue = yield* TxQueue.bounded<
string,
Cause.Done
>(5)
yield* TxQueue.offer(completableQueue, "task")
yield* TxQueue.end(completableQueue)
})
TxEnqueue<function (type parameter) A in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>A, function (type parameter) E in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>E>, cause: Cause.Cause<E>(parameter) cause: {
reasons: ReadonlyArray<Reason<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;
}
import CauseCause.interface Cause<out E>A structured representation of how an Effect failed.
When to use
Use to preserve the full structured failure information for an effect instead
of collapsing it to a single error value.
Details
Access the individual failure entries through the reasons array, then
narrow each entry with
isFailReason
,
isDieReason
, or
- Use
hasFails
/
hasDies
/
hasInterrupts
to test
for the presence of specific reason kinds without iterating.
- Use
findError
/
findDefect
to extract the first value
of a given kind.
- Use
combine
to merge two causes.
Cause implements Equal — two causes with the same reasons (by value)
compare as equal.
Example (Creating and inspecting a cause)
import { Cause } from "effect"
const cause = Cause.fail("Something went wrong")
console.log(cause.reasons.length) // 1
console.log(Cause.isFailReason(cause.reasons[0])) // true
Companion namespace for the Cause interface.
Cause<function (type parameter) E in <A, E>(self: TxEnqueue<A, E>, cause: Cause.Cause<E>): Effect.Effect<boolean>E>): 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<boolean> =>
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 state: State<any, any>state = 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: TxEnqueue<A, E>(parameter) self: {
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
items: TxChunk.TxChunk<any>;
stateRef: TxRef.TxRef<State<any, any>>;
toString: () => string;
toJSON: () => unknown;
}
TxQueueState.stateRef: TxRef.TxRef<State<any, any>>(property) TxQueueState.stateRef: {
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 state: State<any, any>state._tag: "Open" | "Closing" | "Done"_tag !== "Open") {
return false // Already closing/done
}
if (yield* const isEmpty: (
self: TxQueueState
) => Effect.Effect<boolean>
Checks whether the queue is empty.
Example (Checking whether a queue is empty)
import { Effect, TxQueue } from "effect"
const program = Effect.gen(function*() {
const queue = yield* TxQueue.bounded<number>(10)
const empty = yield* TxQueue.isEmpty(queue)
console.log(empty) // true
yield* TxQueue.offer(queue, 42)
const stillEmpty = yield* TxQueue.isEmpty(queue)
console.log(stillEmpty) // false
})
isEmpty(self: TxEnqueue<A, E>(parameter) self: {
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
items: TxChunk.TxChunk<any>;
stateRef: TxRef.TxRef<State<any, any>>;
toString: () => string;
toJSON: () => unknown;
}
import TxRefTxRef.const set: {
<A>(value: A): (
self: TxRef<A>
) => Effect.Effect<void>
<A>(
self: TxRef<A>,
value: A
): Effect.Effect<void>
}
self: TxEnqueue<A, E>(parameter) self: {
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
items: TxChunk.TxChunk<any>;
stateRef: TxRef.TxRef<State<any, any>>;
toString: () => string;
toJSON: () => unknown;
}
TxQueueState.stateRef: TxRef.TxRef<State<any, any>>(property) TxQueueState.stateRef: {
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; <…;
}
_tag: "Done"_tag: "Done", cause: Cause.Cause<E>(property) cause: {
reasons: ReadonlyArray<Reason<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;
}
import TxRefTxRef.const set: {
<A>(value: A): (
self: TxRef<A>
) => Effect.Effect<void>
<A>(
self: TxRef<A>,
value: A
): Effect.Effect<void>
}
self: TxEnqueue<A, E>(parameter) self: {
strategy: "bounded" | "unbounded" | "dropping" | "sliding";
capacity: number;
items: TxChunk.TxChunk<any>;
stateRef: TxRef.TxRef<State<any, any>>;
toString: () => string;
toJSON: () => unknown;
}
TxQueueState.stateRef: TxRef.TxRef<State<any, any>>(property) TxQueueState.stateRef: {
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; <…;
}
_tag: "Closing"_tag: "Closing", cause: Cause.Cause<E>(property) cause: {
reasons: ReadonlyArray<Reason<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;
}
Pipeable.pipe<Effect.Effect<boolean, never, never>, Effect.Effect<boolean, never, never>>(this: Effect.Effect<boolean, never, never>, ab: (_: Effect.Effect<boolean, never, never>) => Effect.Effect<boolean, never, never>): Effect.Effect<boolean, 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)
)