effect-io-ai

Package: effect
Module: Types

Types.UnionToIntersection

Transforms a union type into an intersection type.

When to use

Use to combine all members of a union into a single type with all their properties. This is useful in advanced generic code where you need to merge union variants.

Details

• Uses distributive conditional types and contra-variant inference.
• If the union members are incompatible (e.g. string | number), the result is never.

Example (Converting a union to an intersection)

import type { Types } from "effect"

type Union = { a: string } | { b: number }
type Result = Types.UnionToIntersection<Union>
// { a: string } & { b: number }

See

• IsUnion

Signature

type UnionToIntersection<T> = (T extends any ? (x: T) => any : never) extends (x: infer R) => any ? R
  : never

Source

Since v2.0.0