import { type optics } from "https://deno.land/x/fun@v.2.0.0-alpha.11/mod.ts";
const { Viewer } = optics;
A Viewer<T, S, A> implements a view function (s: S) => T<A>. This is
effectively a Kliesli Arrow. The valid types of T are Identity, Option, and
Array. Viewer also includes a runtime tag corresponding to the return type of
the view function to aid in composition.