<E, B, E2, R2, EB, X extends Cause.Cause<any>>(
filter: Filter.Filter<Cause.Cause<E>, EB, X>,
f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>
): <A, R>(
self: Effect<A, E, R>
) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>
<A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(
self: Effect<A, E, R>,
filter: Filter.Filter<Cause.Cause<E>, EB, X>,
f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>
): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>Recovers from specific failures based on a Filter.
When to use
Use when you need to recover an Effect only from causes selected by a
Filter, while giving the recovery both the selected value and the original
Cause.
Details
The filter is applied to the full Cause. When it succeeds, the handler
receives the selected value and the original cause. When it fails, the effect
re-fails with the residual cause returned by the filter.
export const const catchCauseFilter: {
<E, B, E2, R2, EB, X extends Cause.Cause<any>>(
filter: Filter.Filter<Cause.Cause<E>, EB, X>,
f: (
failure: EB,
cause: Cause.Cause<E>
) => Effect<B, E2, R2>
): <A, R>(
self: Effect<A, E, R>
) => Effect<
A | B,
Cause.Cause.Error<X> | E2,
R | R2
>
<
A,
E,
R,
B,
E2,
R2,
EB,
X extends Cause.Cause<any>
>(
self: Effect<A, E, R>,
filter: Filter.Filter<Cause.Cause<E>, EB, X>,
f: (
failure: EB,
cause: Cause.Cause<E>
) => Effect<B, E2, R2>
): Effect<
A | B,
Cause.Cause.Error<X> | E2,
R | R2
>
}
Recovers from specific failures based on a Filter.
When to use
Use when you need to recover an Effect only from causes selected by a
Filter, while giving the recovery both the selected value and the original
Cause.
Details
The filter is applied to the full Cause. When it succeeds, the handler
receives the selected value and the original cause. When it fails, the effect
re-fails with the residual cause returned by the filter.
catchCauseFilter: {
<function (type parameter) E in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E, function (type parameter) B in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>B, function (type parameter) E2 in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E2, function (type parameter) R2 in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R2, function (type parameter) EB in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>EB, function (type parameter) X in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>X extends 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<any>>(
filter: Filter.Filter<Cause.Cause<E>, 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<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, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E>, function (type parameter) EB in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>EB, function (type parameter) X in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>X>,
f: (
failure: EB,
cause: Cause.Cause<E>
) => Effect<B, E2, R2>
failure: EBfailure: function (type parameter) EB in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>EB, 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, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E>) => 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 <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>B, function (type parameter) E2 in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E2, function (type parameter) R2 in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R2>
): <function (type parameter) A in <A, R>(self: Effect<A, E, R>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>A, function (type parameter) R in <A, R>(self: Effect<A, E, R>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R>(self: Effect<A, E, R>(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; <…;
toString: () => string;
toJSON: () => unknown;
}
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, R>(self: Effect<A, E, R>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>A, function (type parameter) E in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E, function (type parameter) R in <A, R>(self: Effect<A, E, R>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R>) => 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, R>(self: Effect<A, E, R>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>A | function (type parameter) B in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>B, import CauseCause.Cause.type Cause<out E>.Error<T> = T extends Cause.Cause<infer E> ? E : neverExtracts the error type E from a Cause<E>.
Example (Extracting the error type)
import type { Cause } from "effect"
// string
type E = Cause.Cause.Error<Cause.Cause<string>>
Error<function (type parameter) X in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>X> | function (type parameter) E2 in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E2, function (type parameter) R in <A, R>(self: Effect<A, E, R>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R | function (type parameter) R2 in <E, B, E2, R2, EB, X extends Cause.Cause<any>>(filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R2>
<function (type parameter) A in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>A, function (type parameter) E in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E, function (type parameter) R in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R, function (type parameter) B in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>B, function (type parameter) E2 in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E2, function (type parameter) R2 in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R2, function (type parameter) EB in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>EB, function (type parameter) X in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>X extends 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<any>>(
self: Effect<A, E, R>(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; <…;
toString: () => string;
toJSON: () => unknown;
}
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, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>A, function (type parameter) E in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E, function (type parameter) R in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R>,
filter: Filter.Filter<Cause.Cause<E>, 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<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, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E>, function (type parameter) EB in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>EB, function (type parameter) X in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>X>,
f: (
failure: EB,
cause: Cause.Cause<E>
) => Effect<B, E2, R2>
failure: EBfailure: function (type parameter) EB in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>EB, 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, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E>) => 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, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>B, function (type parameter) E2 in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E2, function (type parameter) R2 in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R2>
): 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, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>A | function (type parameter) B in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>B, import CauseCause.Cause.type Cause<out E>.Error<T> = T extends Cause.Cause<infer E> ? E : neverExtracts the error type E from a Cause<E>.
Example (Extracting the error type)
import type { Cause } from "effect"
// string
type E = Cause.Cause.Error<Cause.Cause<string>>
Error<function (type parameter) X in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>X> | function (type parameter) E2 in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>E2, function (type parameter) R in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R | function (type parameter) R2 in <A, E, R, B, E2, R2, EB, X extends Cause.Cause<any>>(self: Effect<A, E, R>, filter: Filter.Filter<Cause.Cause<E>, EB, X>, f: (failure: EB, cause: Cause.Cause<E>) => Effect<B, E2, R2>): Effect<A | B, Cause.Cause.Error<X> | E2, R | R2>R2>
} = import internalinternal.const catchCauseFilter: {
<E, B, E2, R2, EB, X extends Cause.Cause<any>>(
filter: Filter.Filter<Cause.Cause<E>, EB, X>,
f: (
failure: EB,
cause: Cause.Cause<E>
) => Effect.Effect<B, E2, R2>
): <A, R>(
self: Effect.Effect<A, E, R>
) => Effect.Effect<
A | B,
Cause.Cause.Error<X> | E2,
R | R2
>
<
A,
E,
R,
B,
E2,
R2,
EB,
X extends Cause.Cause<any>
>(
self: Effect.Effect<A, E, R>,
filter: Filter.Filter<Cause.Cause<E>, EB, X>,
f: (
failure: EB,
cause: Cause.Cause<E>
) => Effect.Effect<B, E2, R2>
): Effect.Effect<
A | B,
Cause.Cause.Error<X> | E2,
R | R2
>
}