Method compose

repos/effect/packages/effect/src/Optic.ts:537–537

* Composes this optic with another. The result type is the weakest of * the two: Iso + Iso = Iso, Lens + Prism = Optional, etc. * * **Example** (Composing a lens with a prism) * * ```ts * import { Optic, Option } from "effect" * * type State = { value: Option.Option }

(this: Iso<S, A>, that: Iso<A, B>)

   * Focuses on a key where setting `undefined` **removes** the key from the
   * struct (or splices the element from an array/tuple).
   *
   * **Details**
   *
   * - The focus type becomes `A[Key] | undefined`.