modify
import { modify } from "https://github.gh-proxy.cn/raw.githubusercontent.com/baetheus/fun/main/state.ts";Construct a State<E, void> from a function E => E.
@example
import * as S from "./state.ts";
import { pipe } from "./fn.ts";
const state = S.modify((n: number) => n + 100);
const result = state(1); // [undefined, 101]