JavaScript - Starting with the basics - Fruitful subroutines(Ackermann function) - Think JavaScript

Think Perl 6

開発環境

• macOS Sierra - Apple (OS)
• Emacs (Text Editor)
• JavaScript (プログラミング言語)
• Node.js, Safari(JavaScript エンジン)
• Learning JavaScript [邦訳](参考書籍)

Think Perl 6: How to Think Like a Computer Scientist (Laurent Rosenfeld(著)、Allen B. Downey(著)、Oreilly & Associates Inc)のPart 1(Starting with the basics)、Chapter 5(Fruitful subroutines)の Boolean functions の Exercise 5-2.を JavaScript で取り組んでみる。

Exercise 5-2.

コード(Emacs)

let ack = (m, n) => {
    if (m === 0) {
        return n + 1;
    }
    if (m > 0 && n === 0) {
        return ack(m - 1, 1);
    }
    return ack(m - 1, ack(m, n - 1));
};
let result = ack(3, 4);
console.log(result, result == 125);

入出力結果(Terminal, REPL)

$ node sample5_2.js
125 true
$