sidef-scripts/Math/cartesian_product.sf

#!/usr/bin/ruby

# Cartesian product of an arbitrary number of arrays.

func cartesian_product(*arr) {

    var c = []
    var r = []

    func {
        if (c.len < arr.len) {
            for item in (arr[c.len]) {
                c.push(item)
                __FUNC__()
                c.pop
            }
        }
        else {
            r.push([c...])
        }
    }()

    return r
}

cartesian_product(['a', 'b'], ['c', 'd'], ['e', 'f']).each{ .say }

__END__
["a", "c", "e"]
["a", "c", "f"]
["a", "d", "e"]
["a", "d", "f"]
["b", "c", "e"]
["b", "c", "f"]
["b", "d", "e"]
["b", "d", "f"]