Re: [ANN] Lua 5.3.0 (work2) now available

[Bernd Eggink <monoped@...>]

On 24.03.2014 05:49, Dirk Laurie wrote:
> 2014-03-24 2:06 GMT+02:00 Bernd Eggink <monoped@sudrala.de>:
>
> > Is it really intended that
> >
> >      a = math.max(1, 2)
> >
> > returns a = 2.0 (a float)? This change in behaviour, besides being very
> > counterintuitive, kills a lot of my modules which rely on tostring(a) giving
> > "2" (without a decimal part). It means that I would have to surround each
> > such operation with an ifloor() call, which is pretty ineffective and
> > annoying.
> > If that can't be changed, I'd suggest an addition of imin(), imax() and
> > iabs(), witch return integers.
>
> In Lua 5.2, a = math.max(1, 2) returned that same double.

Thanks, I wasn't aware of that.

> The change in behaviour is that a double with the integer value 2 gets
> tostring-ed to "2.0", not to "2". You can restore the original behaviour thus:
>
> $ lua53
> Lua 5.3.0 (work2)  Copyright (C) 1994-2014 Lua.org, PUC-Rio
> > math.max(1,2)
> 2.0
> > debug.setmetatable(0,{__tostring = function(x) return ("%.14g"):format(x) end})
> 0
> > math.max(1,2)
> 2

OK, but I guess I rather replace "math.max(a, b)" by "a > b and a or b",
which is less tricky, but about 4 times faster.

Bernd

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