Simple Automaton (Finite State Machine)

FSM.js

const q3 = () => q2;
const q2 = command => (command === '0' ? q3 : q2);
const q1 = command => (command === '1' ? q2 : q1);

function Automaton1() {
    return {
        readCommands(commands) {
            const lastState = commands.reduce(
                (state, command) => state(command),
                q1
            );
            return lastState.name === q2.name;
        },
    };
}

function* Q3() {
    const command = yield 'q3';
    yield* Q2();
}

function* Q2() {
    const command = yield 'q2';
    yield* command === '0' ? Q3() : Q2();
}

function* Q1() {
    const command = yield 'q1';
    yield* command === '1' ? Q2() : Q1();
}

function Automaton2() {
    return {
        readCommands(commands) {
            const q = Q1();
            q.next();

            const lastQ = commands.reduce(
                (_, command) => q.next(command),
                null
            );

            return lastQ.value === 'q2';
        },
    };
}

var myAutomaton = new Automaton2();

console.assert(myAutomaton.readCommands(['1']), true);
console.assert(myAutomaton.readCommands(['1', '0', '0', '1']), true);