Method tag

packages/effect/src/Optic.ts:664–664

* Narrows the focus to the variant of a tagged union with the given * `_tag` value. * * **Details** * * - On a Prism, returns a Prism. * - On an Optional, returns an Optional. * - Shorthand for `.refine(s => s._tag === tag)`. * - A non-matching value fails wit

(
    this: Prism<S, A>,
    tag: Tag
  )

   * @see `.refine()` — for arbitrary type guards
   */
  tag<S, A extends { readonly _tag: SchemaAST.LiteralValue }, Tag extends A["_tag"]>(
    this: Prism<S, A>,
    tag: Tag
  ): Prism<S, Extract<A, { readonly _tag: Tag }>>