Re: [Caml-list] Just how slow are classes?

[David Rajchenbach-Teller <David.Teller@ens-lyon.org>]

On 18/12/15 12:06, Gerd Stolpmann wrote:
> Oh, this is quickly explained. There is no hierarchy at runtime you can
> exploit. Remember that object X can be a subtype of object Y even if
> there is no inheritance relationship. This is very different from other
> OO languages.

As a side-note, JS JIT engines manage rather well in most common cases,
despite the absence of inheritance. If my memory serves, JIT engines
manage to compile simple lookups to essentially a simple array access
(there's also need to check a tag, I don't remember if the tag is in a
fat pointer or if it needs a dereference).

> 
>>  For now, my primary question is: Just *how* slow are objects/classes?
>> Has there been any relevant benchmarking efforts that could shed some
>> light on this?
> 
> It is essentially an additional hash table lookup.

I thought that the OCaml compiler implemented inline caching in most
common cases?

Cheers,
 David