Re: [patch] changing lua_Number to int64_t

[Lourival Vieira Neto <lourival.neto%gmail.com@localhost>]

On Sun, Nov 17, 2013 at 6:13 PM, Justin Cormack
<justin%specialbusservice.com@localhost> wrote:
> On Sun, Nov 17, 2013 at 7:56 PM, Christos Zoulas 
> <christos%zoulas.com@localhost> wrote:
>> On Nov 17,  3:36pm, lourival.neto%gmail.com@localhost (Lourival Vieira Neto) 
>> wrote:
>> -- Subject: Re: [patch] changing lua_Number to int64_t
>>
>> | > 1. Lua 5.3 will have 64 bit integer support as standard, which will
>> | > make interop and reuse between kernel and userspace code much easier,
>> | > iff we use int64_t
>> |
>> | If they are using int64_t for integers, I think it is a good reason to us 
>> to
>> | stick to int64_t.
>>
>> This is not relevant. The numeric type will still be double, so forget
>> about compatibility between kernel and userland. There is no need for
>> the interpreter to use a fixed width type, but rather it is convenient
>> to use the largest numeric type the machine can represent.
>
> There will be two numeric types as standard, int64_t and double. It
> should be possible to compile the kernel Lua with only int64_t and no
> double support I would think, so integer only userland programs would
> be compatible which is a very useful feature. But the semantics of the
> Lua integer type will be such that it wraps at 64 bit, unlike some
> hypothetical larger type (that doesn't yet exist and which the kernel
> doesn't yet use).

Well, I don't think I fully understood that; mainly because I'm not
aware about Lua 5.3. It will provide two number types for the scripts?
Or you are just talking about lua_Integer type on the C-side. Lua 5.1
already has a lua_Integer type that is defined as ptrdiff_t.

Regards,
-- 
Lourival Vieira Neto