Re: Integer division

[Coda Highland <chighland@...>]

On Wed, Nov 14, 2012 at 9:51 AM, Rena <hyperhacker@gmail.com> wrote:
> On 2012-11-14 12:21 PM, "Petri Häkkinen" <petrih3@gmail.com> wrote:
>>
>> On 14.11.2012, at 8.54, Petri Häkkinen wrote:
>>
>> >> This definition screams for the symbol `/%`.
>> >>
>> >>> q, r = 42 /% 10  --> 4,2
>> >>
>> >> Dirk
>> >>
>> >
>> > Indeed. But /% looks like some sort of escape sequence, I would perhaps
>> > go with %%.
>>
>> Oh, I think I got Dirk's idea the wrong way. I thought you were suggesting
>> /% to be the modulo operator.
>>
>> What I meant was: I would prefer separate operators // and %% (integer
>> division and modulo) over /%. The reason: there are no combined operators
>> +-, */, <> etc. either…. you get the idea  ;-)
>>
>> On 14.11.2012, at 15.37, Roberto Ierusalimschy wrote:
>>
>> >> May I ask what is the opinion of Roberto regarding these new operators?
>> >
>> > I think we always stated that the main problem with bitwise operators
>> > in Lua was that they do not have a "natural" interpretation over Lua
>> > numbers. If Lua gets integers, this problem is gone.
>>
>> That's what I thought. Thanks!
>>
>> Petri
>>
>>
>
> It's maybe worth noting though that a lot of FPUs can give both x / y and x
> % y in a single instruction. Having Lua mirror this by having two values
> returned from % seems like it'd make possible optimization easier.
>
> But I wonder if there's existing code that might break, such as f(x % y) now
> passing an extra argument?

All the more reason to do it with a new operator.

/s/ Adam