XProduct · Software Engineering Wiki

Creates a new slice out of the two supplied by creating each possible pair from the collections.

Use reflect.ValueOf() to get the arrays or slices, Value.Len() and make() to create an appropriate slice for the result.
Use a for loop with Value.Len(), Value.Index() and Value.Interface() to populate the result.

import "reflect"

func XProduct(params ...interface{}) [][]interface{} {
	a, b := reflect.ValueOf(params[0]), reflect.ValueOf(params[1])
	l := a.Len() * b.Len()
	r := make([][]interface{}, l)

	for i := 0; i < l; i++ {
		r[i] = []interface{}{
			a.Index(i % a.Len()).Interface(),
			b.Index((i / a.Len()) % b.Len()).Interface(),
		}
	}
	return r

}

XProduct([]int{1, 2}, []string{"a", "b"}) // [[1 a] [2 a] [1 b] [2 b]]