Re: Integer division

[GrayFace <sergroj@...>]

Will integer-valued floats be converted to integers when used as table 
keys? Otherwise the array part of tables optimization will fail. What 
would happen after this code: "t = {0}; t[1.0] = 0;"?
All this doesn't feel like a good idea to me.
I think 32-bit integers would be beneficial to speed as an 
implementation detail, producing float result in case of integer 
overflow of an operation. (wrote this before I saw the comment about 
existing patch)
I'm totally with Wolfgang Pupp about 64-bit integers, except I'm not 
advocating for making them heavy userdata (more on this in a moment) and 
think that tostring should output "5" for such number, not "5ll". But 
64-bit number are domain-specific, not needed most of the time, so they 
should be separated from regular numbers. And it's not about 
compatibility, it's about keeping Lua clean.
It would actually be great to have subtypes of lightweight userdata, and 
it's a perfect fit for 64-bit ints. In Lua there is free space for 
"small subtype" field in value struct. Light userdata values of 
different subtypes would be different. Add a function to allocate the 
subtype, functions to create typed light userdata and check subtype and 
it will be a very nice addition.

On 22.11.2012 22:04, Roberto Ierusalimschy wrote:
> Moreover, it does not address the other part of the current proposal: 
> to make Lua better for small platforms with no hardware support for 
> doubles. -- Roberto 

It's unclear to me how your proposal would help with this task.

Integer division operator is good anyway, with or without integers as 
types. How about '\'? Both '\' and '//' are already used as integer 
devision operator in some languages. E.g. '\' is used in ColdFusion.

--
Best regards,
Sergey Rozhenko                 mailto:sergroj@mail.ru