Re: 5.4 with arrays patch (work in progress)

[Dibyendu Majumdar <mobile@...>]

On 18 March 2018 at 14:44, Dibyendu Majumdar <mobile@majumdar.org.uk> wrote:
> On 18 March 2018 at 14:25, Petri Häkkinen <petrih3@gmail.com> wrote:
>>>
>>> Anyone willing to step up and write a patch for arrays? I bet it would solve the issues with #, make Lua code clearer about its intent and also give a nice perf boost. As arrays would be a new lang feature, existing code would not be affected at all.
>>>
>>> A good proof of concept and demonstration how it solves the issues might be all that is needed to convince Roberto et all that this is the right way to go ;-)
>>>
>>> Heck, this could be the killer feature of 6.0 that would make people stuck in 5.1 to jump aboard.
>>>
>>> If not, then at least we could drop this talk about arrays and move on.
>>>
>>> Any takers?
>>>
>>> Petri
>>
>> Well, I took a stab at it myself for some Sunday fun. It’s still very much work in progress, but the initial results seem promising.
>>
>> Code and benchmarks at: https://github.com/petrihakkinen/lua-array
>>
>
> Looks like we posted at the same time.
>
> I see that you have created a new array type. My approach in Ravi is
> to create sub types of Table (similar to how Integer sub type of
> Number works). Having a separate type does have some advantages - one
> can optimize the structure for arrays, for example.
>
> BTW you also need to update all the Lua api functions so that they
> work transparently on arrays.
>

Also be aware that main Lua type codes are 4 bits and there are two
additional bits used for type variants:

Here is some doc that is for Ravi but should mostly be correct for Lua too.

https://github.com/dibyendumajumdar/ravi/wiki/LuaTypeCodes.

Recently I made a change in Ravi to move the collectible bit to the
left by 1 so that allows 3 bits for encoding variants.

Regards
Dibyendu