Numbers

num = den =

real = img =

Stack:

+i
1/2

class Make { //Factory methods for numbers
    static whole(n) {
        return new Whole(n);
    }
    static rational(n, d) {
        if (d < 0) { n = -n; d = -d; }
        let g = Rational.gcd(n, d);
        if (g == d) return new Whole(n/g);
        return new Rational(n/g, d/g);
    }
    static decimal(x) {
        if (x == Math.round(x)) 
             return new Whole(x);
        return new Decimal(x);
    }
    static complex(re, im) {
        if (im == 0) 
             return Make.decimal(re);
        return new Complex(re, im);
    }
    static fromString(s) {
        if (typeof s == "number") 
            return Make.decimal(s);
        let [n, d] = s.split('/')
        if (d) return Make.rational(n, d)
        let [re, im] = s.split('+i')
        if (im) return Make.complex(re, im)
        [re, im] = s.split('-i')
        if (im) return Make.complex(re, -im)
        return Make.decimal(Number(s));
    }
}