undefined method `to_msgpack' for Cql::TimeUuid & bignum too big to convert about msgpack-ruby

[Micka33]

Issue originally posted in msgpack/msgpack#188

[iconara]

I disagree. I don't think it would be a good idea to make #to_msgpack use #as_json. That method is not at all standardized and would mean that MessagePack started acting differently when you load another gem that happens to add #to_json to things.

For example: Cql::TimeUuid doesn't have a #as_json method (I know, I'm the author of cql-rb, where that class comes from, I assume that it's Cequel that adds it). If you decided to use cql-rb directly and not through Cequel, or just copied the code to a project where you don't use Cequel your code would suddenly stop working.

[iconara]

An alternative, that wouldn't have the same problem, would be to check for a #to_h method and fall back on that it if exists. There would still be no guarantee that the value returned from the method would be MessagePack'able.

At the same time, this is what the MessagePack extensions should be used for. The Ruby and JRuby implementations don't support them very well at the moment, unfortunately.

[Micka33]

I didn't realize as_json was a rails only method! to_h seems to be a good alternative then.

What about the bignum too big to convert error? (Should I open a new issue?)

irb(main):002:0> {"n"=>81669062298108866050539035482603516879}.to_msgpack
RangeError: bignum too big to convert into `unsigned long long'
    from (irb):2:in `to_msgpack'
    from (irb):2
    from /Users/mickael/.rvm/rubies/ruby-2.1.5/bin/irb:11:in `<main>'

[iconara]

What about the bignum too big to convert error? (Should I open a new issue?)

It's easier to track issues if they are reported separately, so yes please. We can leave this issue open as a feature request for the #to_msgpack/#to_h thing.

[Micka33]

Created it in #57

[cosmo0920]

If you want msgpack to support big integer, comment is welcomed in msgpack repo's issue: msgpack/msgpack#206

[simonrussell]

Isn't this what custom serialisation (extension types) is for?

[tagomoris]

Right. Use ext types for this purpose. I missed to close this.