That's cool, In Ruby Hash merges are really expensive. I played around with a non-mutating data structure that uses references two two hashes and behaves as if

That's cool, In Ruby Hash merges are really expensive. I played around with a non-mutating data structure that uses references two two hashes and behaves as if it had been merged instead of allocating. It was a fun thought experiment but wasn't 100% API backwards compatible, as mutations got ugly. Thanks for the link.