Returns Reader<R, R>

The fetching computation.

Examples

import { ask, map, Reader, run } from "./reader.ts";
import { cat } from "./cat.ts";
import { assertEquals } from "../deps.ts";

interface User {
    name: string;
}
const message = (): Reader<User, string> =>
    cat(ask<User>()).feed(map(({ name }) => `Hello, ${name}!`)).value;
const box = (): Reader<User, string> =>
    cat(message()).feed(
        map((mes) => `<div class="message-box">${mes}</div>`),
    ).value;

assertEquals(
    run(box())({ name: "John" }),
    '<div class="message-box">Hello, John!</div>',
);
assertEquals(
    run(box())({ name: "Alice" }),
    '<div class="message-box">Hello, Alice!</div>',
);
Copy