<E>(evaluate: LazyArg<E>): Effect<never, E>Creates an Effect that represents a recoverable error using a lazy evaluation.
When to use
Use to defer computing a recoverable error value until the effect is run.
Details
The error-producing function is evaluated each time the effect is executed.
Example (Lazily creating failures)
import { Data, Effect } from "effect"
class ProgramError extends Data.TaggedError("ProgramError")<{ readonly failedAt: Date }> {}
const program = Effect.failSync(() => new ProgramError({ failedAt: new Date() }))
Effect.runPromiseExit(program).then(console.log)
// Output: { _id: 'Exit', _tag: 'Failure', cause: ... }export const const failSync: <E>(
evaluate: LazyArg<E>
) => Effect<never, E>
Creates an Effect that represents a recoverable error using a lazy evaluation.
When to use
Use to defer computing a recoverable error value until the effect is run.
Details
The error-producing function is evaluated each time the effect is executed.
Example (Lazily creating failures)
import { Data, Effect } from "effect"
class ProgramError extends Data.TaggedError("ProgramError")<{ readonly failedAt: Date }> {}
const program = Effect.failSync(() => new ProgramError({ failedAt: new Date() }))
Effect.runPromiseExit(program).then(console.log)
// Output: { _id: 'Exit', _tag: 'Failure', cause: ... }
failSync: <function (type parameter) E in <E>(evaluate: LazyArg<E>): Effect<never, E>E>(evaluate: LazyArg<E>evaluate: type LazyArg<A> = () => AA zero-argument function that produces a value when invoked.
When to use
Use to type a lazy value provider that should not run until called.
Example (Creating a lazy argument)
import { Function } from "effect"
const constNull: Function.LazyArg<null> = Function.constant(null)
LazyArg<function (type parameter) E in <E>(evaluate: LazyArg<E>): Effect<never, E>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<never, function (type parameter) E in <E>(evaluate: LazyArg<E>): Effect<never, E>E> = import internalinternal.const failSync: <E>(
error: LazyArg<E>
) => Effect.Effect<never, E>