Typescript example DSL

dsl.ts

interface MyProgramDSL<T> {
    read: () => Promise<string>;
    write: (value: string) => Promise<void>
    done: (value: T) => Promise<T>
}

const MyProgram = async ({ read, write, done }: MyProgramDSL<string>) => {
    await write("Hello, what is your name?");
    const name = await read();
    return done(`Your name: ${name}, has ${name.length} letters.`);
}

const promptAlertInterpreter = <T>() => ({
    read: async () => prompt(),
    write: async (value: string) => alert(value),
    done: async (value: T) => value
});

class PlatformConsoleInterpreter<T> implements MyProgramDSL<T> {
    async read() { return navigator.platform }
    async write(value) { console.log(value) }
    async done(value) { return value }
}

MyProgram(promptAlertInterpreter<string>()).then(alert);

MyProgram(new PlatformConsoleInterpreter).then(console.log);