1 files changed, 54 insertions, 0 deletions
diff --git a/pkg/common/cartesian.go b/pkg/common/cartesian.go
new file mode 100644
index 0000000..9cd6065
--- /dev/null
+++ b/pkg/common/cartesian.go
@@ -0,0 +1,54 @@
+package common
+
+// CartesianProduct takes map of lists and returns list of unique tuples
+func CartesianProduct(mapOfLists map[string][]interface{}) []map[string]interface{} {
+	listNames := make([]string, 0)
+	lists := make([][]interface{}, 0)
+	for k, v := range mapOfLists {
+		listNames = append(listNames, k)
+		lists = append(lists, v)
+	}
+
+	listCart := cartN(lists...)
+
+	rtn := make([]map[string]interface{}, 0)
+	for _, list := range listCart {
+		vMap := make(map[string]interface{})
+		for i, v := range list {
+			vMap[listNames[i]] = v
+		}
+		rtn = append(rtn, vMap)
+	}
+	return rtn
+}
+
+func cartN(a ...[]interface{}) [][]interface{} {
+	c := 1
+	for _, a := range a {
+		c *= len(a)
+	}
+	if c == 0 || len(a) == 0 {
+		return nil
+	}
+	p := make([][]interface{}, c)
+	b := make([]interface{}, c*len(a))
+	n := make([]int, len(a))
+	s := 0
+	for i := range p {
+		e := s + len(a)
+		pi := b[s:e]
+		p[i] = pi
+		s = e
+		for j, n := range n {
+			pi[j] = a[j][n]
+		}
+		for j := len(n) - 1; j >= 0; j-- {
+			n[j]++
+			if n[j] < len(a[j]) {
+				break
+			}
+			n[j] = 0
+		}
+	}
+	return p
+}