Re: Using numbers as float

[Mark Edgar <medgar@...>]

Jose Marin wrote:
> Hi.
>
> I'm compiling Lua to use floats, altering the file
> luser_number.h .
>
> The macro lua_str2number uses strtod (returns a
> double).
>
> I could cast to (float)strtod, but I'm worried abou
> performance.
>
> Is there some fast way of convert a string to a float?
>
> Thanks!

strtod() works just fine; no cast is required:

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
  float x = strtod("3.2", NULL);
  printf("%f\n", x);
  return 0;
}

You probably won't find anything faster, as your implementation's 
strtod() is probably written in nice fast assembly.

If you have a C99 conforming system, you can use strtof() instead.  I 
don't know that you'll notice a performance difference between strtod() 
and strtof().

					-Mark