Function withFlat

packages/effect/src/Context.ts:522–526

(self: Context<any>, f: (map: Map<string, any>) => void)

}

const withFlat = <B>(self: Context<any>, f: (map: Map<string, any>) => void): Context<B> => {
  const map = new Map(self.mapUnsafe)
  f(map)
  return makeUnsafe(map)
}

// A private symbol so user code cannot forge a value that reads as absent
const notFound = Symbol()