import { Option } from "effect";

type User = Readonly<{
    name: string;
    email: Option.Option<string>;  
}>

const getUserEmailDomain = (user: User) => Option.gen(function *() {
    const email = yield* user.email;
    const [, domain] = email.split("@");
    return domain;
})

const someUser = Option.some({
    name: "User",
    email: Option.some("[email protected]"),
})

const domain = Option.flatMap(someUser, getUserEmailDomain)

import { Array } from "effect";

const cartesianProduct = <A, B>(xs: Array<A>, ys: Array<B>): Array<[A, B]> => Array.gen(function *() {
    const x = yield* xs;
    const y = yield* ys;
    return [x, y];
})

const x: Array<number> = [1, 2];
const y: Array<number> = [3, 4];

const xy = cartesianProduct(x, y); // [ [1, 3], [1, 4], [2, 3], [2, 4] ]

const cartesianProduct = <A, B>(xs: Array<A>, ys: Array<B>): Array<[A, B]> => pipe(
    Array.Do,
    Array.bind("x", () => xs),
    Array.bind("y", () => ys),
    Array.map(({ x, y }) => [x, y])
)