Function sub [src]

rma = a - b. rma, a and b may be aliases. However, it is more efficient if rma does not alias a or b. Returns an error if memory could not be allocated.

Prototype

pub fn sub(rma: *Rational, a: Rational, b: Rational) !void

Parameters

rma: *Rationala: Rationalb: Rational

Source

  pub fn sub(rma: *Rational, a: Rational, b: Rational) !void {
    var r = rma;
    var aliased = rma.p.limbs.ptr == a.p.limbs.ptr or rma.p.limbs.ptr == b.p.limbs.ptr;

    var sr: Rational = undefined;
    if (aliased) {
        sr = try Rational.init(rma.p.allocator);
        r = &sr;
        aliased = true;
    }
    defer if (aliased) {
        rma.swap(r);
        r.deinit();
    };

    try r.p.mul(&a.p, &b.q);
    try r.q.mul(&b.p, &a.q);
    try r.p.sub(&r.p, &r.q);

    try r.q.mul(&a.q, &b.q);
    try r.reduce();
}  