tpl/math: Refactor Mod with cast

It makes the code smaller

tpl/math/math.go

@@ -72,21 +72,10 @@ func (ns *Namespace) Log(a interface{}) (float64, error) {
 
 // Mod returns a % b.
 func (ns *Namespace) Mod(a, b interface{}) (int64, error) {
-	av := reflect.ValueOf(a)
+	ai, erra := cast.ToInt64E(a)
-	bv := reflect.ValueOf(b)
+	bi, errb := cast.ToInt64E(b)
-	var ai, bi int64
 
-	switch av.Kind() {
+	if erra != nil || errb != nil {
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		ai = av.Int()
-	default:
-		return 0, errors.New("Modulo operator can't be used with non integer value")
-	}
-
-	switch bv.Kind() {
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		bi = bv.Int()
-	default:
 		return 0, errors.New("Modulo operator can't be used with non integer value")
 	}
 

tpl/math/math_test.go

@@ -259,13 +259,17 @@ func TestMod(t *testing.T) {
 		{3, 1, int64(0)},
 		{3, 0, false},
 		{0, 3, int64(0)},
-		{3.1, 2, false},
+		{3.1, 2, int64(1)},
-		{3, 2.1, false},
+		{3, 2.1, int64(1)},
-		{3.1, 2.1, false},
+		{3.1, 2.1, int64(1)},
 		{int8(3), int8(2), int64(1)},
 		{int16(3), int16(2), int64(1)},
 		{int32(3), int32(2), int64(1)},
 		{int64(3), int64(2), int64(1)},
+		{"3", "2", int64(1)},
+		{"3.1", "2", false},
+		{"aaa", "0", false},
+		{"3", "aaa", false},
 	} {
 		errMsg := fmt.Sprintf("[%d] %v", i, test)
 
@@ -296,9 +300,9 @@ func TestModBool(t *testing.T) {
 		{3, 1, true},
 		{3, 0, nil},
 		{0, 3, true},
-		{3.1, 2, nil},
+		{3.1, 2, false},
-		{3, 2.1, nil},
+		{3, 2.1, false},
-		{3.1, 2.1, nil},
+		{3.1, 2.1, false},
 		{int8(3), int8(3), true},
 		{int8(3), int8(2), false},
 		{int16(3), int16(3), true},
@@ -307,6 +311,11 @@ func TestModBool(t *testing.T) {
 		{int32(3), int32(2), false},
 		{int64(3), int64(3), true},
 		{int64(3), int64(2), false},
+		{"3", "3", true},
+		{"3", "2", false},
+		{"3.1", "2", nil},
+		{"aaa", "0", nil},
+		{"3", "aaa", nil},
 	} {
 		errMsg := fmt.Sprintf("[%d] %v", i, test)