extract common part from ArrayEncode and SliceEncode into function

Author: roman.tarasov

bson/bsoncodec/default_value_encoders.go

@@ -33,6 +33,27 @@ var sliceWriterPool = sync.Pool{
 	},
 }
 
+func encodeElement(ec EncodeContext, dw bsonrw.DocumentWriter, e primitive.E) error {
+	vw, err := dw.WriteDocumentElement(e.Key)
+	if err != nil {
+		return err
+	}
+
+	if e.Value == nil {
+		return vw.WriteNull()
+	}
+	encoder, err := ec.LookupEncoder(reflect.TypeOf(e.Value))
+	if err != nil {
+		return err
+	}
+
+	err = encoder.EncodeValue(ec, vw, reflect.ValueOf(e.Value))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
 // DefaultValueEncoders is a namespace type for the default ValueEncoders used
 // when creating a registry.
 type DefaultValueEncoders struct{}
@@ -304,27 +325,10 @@ func (dve DefaultValueEncoders) ArrayEncodeValue(ec EncodeContext, vw bsonrw.Val
 
 		for idx := 0; idx < val.Len(); idx++ {
 			e := val.Index(idx).Interface().(primitive.E)
-			vw, err := dw.WriteDocumentElement(e.Key)
+			err = encodeElement(ec, dw, e)
 			if err != nil {
 				return err
 			}
-
-			if e.Value == nil {
-				err = vw.WriteNull()
-				if err != nil {
-					return err
-				}
-			} else {
-				encoder, err := ec.LookupEncoder(reflect.TypeOf(e.Value))
-				if err != nil {
-					return err
-				}
-
-				err = encoder.EncodeValue(ec, vw, reflect.ValueOf(e.Value))
-				if err != nil {
-					return err
-				}
-			}
 		}
 
 		return dw.WriteDocumentEnd()
@@ -374,27 +378,10 @@ func (dve DefaultValueEncoders) SliceEncodeValue(ec EncodeContext, vw bsonrw.Val
 		}
 
 		for _, e := range d {
-			vw, err := dw.WriteDocumentElement(e.Key)
+			err = encodeElement(ec, dw, e)
 			if err != nil {
 				return err
 			}
-
-			if e.Value == nil {
-				err = vw.WriteNull()
-				if err != nil {
-					return err
-				}
-			} else {
-				encoder, err := ec.LookupEncoder(reflect.TypeOf(e.Value))
-				if err != nil {
-					return err
-				}
-
-				err = encoder.EncodeValue(ec, vw, reflect.ValueOf(e.Value))
-				if err != nil {
-					return err
-				}
-			}
 		}
 
 		return dw.WriteDocumentEnd()