effect-io-ai

Package: effect
Module: Struct

Struct.Assign

Merges two object types with properties from U taking precedence over T on overlapping keys (like Object.assign at the type level).

When to use

Use when you need the type-level equivalent of { ...T, ...U }.

Details

When no keys overlap, this returns a simple intersection for efficiency. When keys overlap, the type from U wins.

Example (Merging two types with overlapping keys)

import type { Struct } from "effect"

type A = { a: string; b: number }
type B = { b: boolean; c: string }
type Merged = Struct.Assign<A, B>
// { a: string; b: boolean; c: string }

See

• assign – the runtime equivalent
• Simplify – flatten the resulting intersection

Signature

type { [K in keyof (keyof T & keyof U extends never ? T & U : Omit<T, keyof T & keyof U> & U)]: (keyof T & keyof U extends never ? T & U : Omit<T, keyof T & keyof U> & U)[K]; } = Simplify<keyof T & keyof U extends never ? T & U : Omit<T, keyof T & keyof U> & U>

Source

Since v4.0.0