1 files changed, 26 insertions, 0 deletions
diff --git a/subex/filter.go b/subex/filter.go
index dce0f0e..309d6c7 100644
--- a/subex/filter.go
+++ b/subex/filter.go
@@ -27,6 +27,26 @@ func (_ anyBoolFilter) valueFilter(value walk.Value) bool {
 	return isBool
 }
 
+type simpleValueFilter struct {}
+func (_ simpleValueFilter) valueFilter(value walk.Value) bool {
+	switch value := value.(type) {
+	case walk.NullValue:
+		return true
+	case walk.BoolValue:
+		return true
+	case walk.NumberValue:
+		return true
+	case walk.StringValue:
+		return true
+	case walk.ArrayValue:
+		return len(value) == 0
+	case walk.MapValue:
+		return len(value) == 0
+	default:
+		panic("Invalid value type")
+	}
+}
+
 type anyValueFilter struct {}
 func (_ anyValueFilter) valueFilter(value walk.Value) bool {
 	return true
@@ -38,6 +58,12 @@ func (_ anyArrayFilter) valueFilter(value walk.Value) bool {
 	return isArray
 }
 
+type anyMapFilter struct {}
+func (_ anyMapFilter) valueFilter(value walk.Value) bool {
+	_, isMap := value.(walk.MapValue)
+	return isMap
+}
+
 type anyStringFilter struct {}
 func (_ anyStringFilter) valueFilter(value walk.Value) bool {
 	_, isString := value.(walk.StringValue)