effect-io-ai

Package: effect
Module: Unify

Unify.Unify

Unifies types that implement the unification protocol.

When to use

Use to normalize unions of types that expose Effect’s unification protocol.

Details

This type performs automatic type unification for types that contain the unification symbols (unifySymbol, typeSymbol, ignoreSymbol). It’s primarily used internally by the Effect type system to handle complex type unions and provide better type inference.

Example (Unifying protocol types)

import type { Unify } from "effect"

// Example of types that can be unified
type UnifiableA = {
  value: string
  [Unify.typeSymbol]?: string
  [Unify.unifySymbol]?: { String: () => string }
}

type UnifiableB = {
  value: number
  [Unify.typeSymbol]?: number
  [Unify.unifySymbol]?: { Number: () => number }
}

// Unify automatically handles the union
type Unified = Unify.Unify<UnifiableA | UnifiableB>
// Results in a properly unified type

See

• unify for applying this normalization to a value or function

Signature

type Unify<A> = Values<
  ExtractTypes<
    (
      & FilterIn<A>
      & { [typeSymbol]: A }
    )
  >
> extends infer Z ?
    | Z
    | FilterInUnmatched<
      A,
      Keys<
        ExtractTypes<
          (
            & FilterIn<A>
            & { [typeSymbol]: A }
          )
        >
      >
    >
    | FilterOut<A>
  : never

Source

Since v2.0.0