直接或通过返回操作结构

Question

I noticed that I am not consistent when writing golang regarding the following question: Is it better to manipulate a struct in its methods via the struct itself directly or by using return? Since this question sounds stupid, here's an example:

Manipulate a struct directly

http://play.golang.org/p/7G5D8Pm5wv

Via return

http://play.golang.org/p/L9Z_t7pA8b

Please explain why one attempt is better than the other. An if both somehow wrong, please give an example that would be ok.

Thanks in advance!

Answer 1

I think it depends on how you use your struct. If you use it as an object i.e. there function with receivers of that type I think you should manipulate the state (the fields of the struct) with functions too. If you use the struct purely as a data store, then manipulating the fields directly seems more OK.

Read

Clean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin, chapter 6 on Objects & Data structures

Google for that book and you will find online versions.

and

http://en.wikipedia.org/wiki/Law_of_Demeter