<N extends string, A extends Record<string, any>, B, E2, R2>(
name: N,
f: (a: NoInfer<A>) => Effect<B, E2, R2>
): <E, R>(
self: Effect<A, E, R>
) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>
<A extends Record<string, any>, E, R, B, E2, R2, N extends string>(
self: Effect<A, E, R>,
name: N,
f: (a: NoInfer<A>) => Effect<B, E2, R2>
): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>Adds an Effect value to the do notation record under a given name.
When to use
Use to sequence an effectful step in a do-notation pipeline when that step depends on fields already accumulated in the record and its success value should be stored under a name.
Details
The function receives the current record, runs the returned effect after the
input effect succeeds, and inserts its success value under name. The
resulting effect combines the error and service requirements of both steps.
Gotchas
Binding a name that already exists replaces that field in the resulting record.
export const const bind: {
<
N extends string,
A extends Record<string, any>,
B,
E2,
R2
>(
name: N,
f: (a: NoInfer<A>) => Effect<B, E2, R2>
): <E, R>(
self: Effect<A, E, R>
) => Effect<
Simplify<Omit<A, N> & Record<N, B>>,
E | E2,
R | R2
>
<
A extends Record<string, any>,
E,
R,
B,
E2,
R2,
N extends string
>(
self: Effect<A, E, R>,
name: N,
f: (a: NoInfer<A>) => Effect<B, E2, R2>
): Effect<
Simplify<Omit<A, N> & Record<N, B>>,
E | E2,
R | R2
>
}
Adds an Effect value to the do notation record under a given name.
When to use
Use to sequence an effectful step in a do-notation pipeline when that step
depends on fields already accumulated in the record and its success value
should be stored under a name.
Details
The function receives the current record, runs the returned effect after the
input effect succeeds, and inserts its success value under name. The
resulting effect combines the error and service requirements of both steps.
Gotchas
Binding a name that already exists replaces that field in the resulting
record.
bind: {
<function (type parameter) N in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N extends string, function (type parameter) A in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A extends type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<string, any>, function (type parameter) B in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>B, function (type parameter) E2 in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E2, function (type parameter) R2 in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R2>(
name: N extends stringname: function (type parameter) N in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N,
f: (a: NoInfer<A>) => Effect<B, E2, R2>f: (a: NoInfer<A>a: type NoInfer<A> = [A][A extends any ? 0 : never]Prevents TypeScript from inferring a type parameter from a specific
position.
When to use
Use when a function parameter must match an inferred type without becoming
an inference source.
Details
The parameter using NoInfer must still match the inferred type.
Example (Controlling inference)
import type { Types } from "effect"
declare function withDefault<T>(value: T, fallback: Types.NoInfer<T>): T
// T is inferred as "a" | "b" from the first argument only
const result = withDefault<"a" | "b">("a", "b")
NoInfer<function (type parameter) A in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A>) => 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 <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>B, function (type parameter) E2 in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E2, function (type parameter) R2 in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R2>
): <function (type parameter) E in <E, R>(self: Effect<A, E, R>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E, function (type parameter) R in <E, R>(self: Effect<A, E, R>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | 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 <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A, function (type parameter) E in <E, R>(self: Effect<A, E, R>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E, function (type parameter) R in <E, R>(self: Effect<A, E, R>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | 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<type Simplify<A> = { [K in keyof A]: A[K]; } extends infer B ? B : neverFlattens an intersection type into a single object type for readability.
When to use
Use to clean up IDE tooltips that show A & B & C instead of a merged
object.
Details
Does not change the type semantically, only its display.
Example (Simplifying an intersection)
import type { Types } from "effect"
// Without Simplify: IDE shows { a: number } & { b: string }
// With Simplify: IDE shows { a: number; b: string }
type Clean = Types.Simplify<{ a: number } & { b: string }>
Simplify<type Omit<T, K extends keyof any> = {
[P in Exclude<keyof T, K>]: T[P]
}
Construct a type with the properties of T except for those in type K.
Omit<function (type parameter) A in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A, function (type parameter) N in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N> & type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<function (type parameter) N in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N, function (type parameter) B in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>B>>, function (type parameter) E in <E, R>(self: Effect<A, E, R>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E | function (type parameter) E2 in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E2, function (type parameter) R in <E, R>(self: Effect<A, E, R>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R | function (type parameter) R2 in <N extends string, A extends Record<string, any>, B, E2, R2>(name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): <E, R>(self: Effect<A, E, R>) => Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R2>
<function (type parameter) A in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A extends type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<string, any>, function (type parameter) E in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E, function (type parameter) R in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R, function (type parameter) B in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>B, function (type parameter) E2 in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E2, function (type parameter) R2 in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R2, function (type parameter) N in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N extends string>(
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 extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A, function (type parameter) E in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E, function (type parameter) R in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R>,
name: N extends stringname: function (type parameter) N in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N,
f: (a: NoInfer<A>) => Effect<B, E2, R2>f: (a: NoInfer<A>a: type NoInfer<A> = [A][A extends any ? 0 : never]Prevents TypeScript from inferring a type parameter from a specific
position.
When to use
Use when a function parameter must match an inferred type without becoming
an inference source.
Details
The parameter using NoInfer must still match the inferred type.
Example (Controlling inference)
import type { Types } from "effect"
declare function withDefault<T>(value: T, fallback: Types.NoInfer<T>): T
// T is inferred as "a" | "b" from the first argument only
const result = withDefault<"a" | "b">("a", "b")
NoInfer<function (type parameter) A in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A>) => 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 extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>B, function (type parameter) E2 in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E2, function (type parameter) R2 in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | 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<type Simplify<A> = { [K in keyof A]: A[K]; } extends infer B ? B : neverFlattens an intersection type into a single object type for readability.
When to use
Use to clean up IDE tooltips that show A & B & C instead of a merged
object.
Details
Does not change the type semantically, only its display.
Example (Simplifying an intersection)
import type { Types } from "effect"
// Without Simplify: IDE shows { a: number } & { b: string }
// With Simplify: IDE shows { a: number; b: string }
type Clean = Types.Simplify<{ a: number } & { b: string }>
Simplify<type Omit<T, K extends keyof any> = {
[P in Exclude<keyof T, K>]: T[P]
}
Construct a type with the properties of T except for those in type K.
Omit<function (type parameter) A in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>A, function (type parameter) N in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N> & type Record<K extends keyof any, T> = {
[P in K]: T
}
Construct a type with a set of properties K of type T
Record<function (type parameter) N in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>N, function (type parameter) B in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>B>>, function (type parameter) E in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E | function (type parameter) E2 in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>E2, function (type parameter) R in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R | function (type parameter) R2 in <A extends Record<string, any>, E, R, B, E2, R2, N extends string>(self: Effect<A, E, R>, name: N, f: (a: NoInfer<A>) => Effect<B, E2, R2>): Effect<Simplify<Omit<A, N> & Record<N, B>>, E | E2, R | R2>R2>
} = import internalinternal.const bind: {
<
N extends string,
A extends Record<string, any>,
B,
E2,
R2
>(
name: N,
f: (a: NoInfer<A>) => Effect.Effect<B, E2, R2>
): <E, R>(
self: Effect.Effect<A, E, R>
) => Effect.Effect<
Simplify<Omit<A, N> & Record<N, B>>,
E | E2,
R | R2
>
<
A extends Record<string, any>,
E,
R,
B,
E2,
R2,
N extends string
>(
self: Effect.Effect<A, E, R>,
name: N,
f: (a: NoInfer<A>) => Effect.Effect<B, E2, R2>
): Effect.Effect<
Simplify<Omit<A, N> & Record<N, B>>,
E | E2,
R | R2
>
}