Re: Unexpected randomseed results (was [ANN] uuid: pure Lua uuid generator)
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: Unexpected randomseed results (was [ANN] uuid: pure Lua uuid generator)
- From: Sean Conner <sean@...>
- Date: 2013年5月11日 04:22:32 -0400
It was thus said that the Great Sean Conner once stated:
>
> In thinking about it, Lua should do the following:
>
> srand(luaL_checkint(L,1) % INT_MAX);
Ooops, that's silly. What I meant was:
srand((unsigned int)fmod(luaL_checknumber(L,1),UINT_MAX));
for both Lua 5.1 and 5.2.
Or perhaps:
double ds = luaL_checknumber(L,1);
unsigned int s;
if (ds < 1.0)
s = (unsigned int)(ds * (double)UINT_MAX);
else if (ds > UINT_MAX)
s = (unsigned int)fmod(ds,UINT_MAX);
else
s = (unsigned int)ds;
srand(ds);
to force it into a range of 0 .. UINT_MAX.
-spc (Or just keep it as is and be a bit more careful about seeding)