Re: Lua 5.1 (beta) now available

[Rici Lake <lua@...>]

On 18-Nov-05, at 10:05 AM, Mike Pall wrote:

> - Even after a few days of discovering it, I'm not sure what
>   table.maxn() is good for. IMHO it's superfluous and may
>   confuse newbies.

I agree (see <http://lua-users.org/lists/lua-l/2005-11/msg00133.html>)

> - I suggest to make the NaN tests explicit and overridable:
>
>     #define luai_numisnan(a) ((a)!=(a))
>
>   [In case anyone wonders: isnan() is only defined in C99.]

I'm not convinced by this. (I agree with making the test explicit, just 
not with the avoidance of isnan()). isnan() is in POSIX (since Issue 3, 
it says here); furthermore, it has quite a long history of being 
implemented, including in all the IEEE-754 emulation libraries I've 
used. (It may require #include <ieee.h>, or some other non-standard 
header.)  On the other hand, I've certainly seen C compilers (though I 
admit not for a long time) which would cheerfully optimize away the 
(a)!=(a) check (which certainly should be optimized away if a is an 
integer type.)