Re: [Chicken-users] bug and potential fix for numbers egg

[Alex Shinn]

>>>>> "John" == John Cowan <address@hidden> writes:

    John> Alex Shinn scripsit:
    >> As a potential workaround, I've attached a patch
    >> which first checks if both the numerator and
    >> denominator fit within a long (there's no direct way
    >> to check if they fit in a double), and if so just
    >> uses the straight C operations
    >> 
    >> (double) numerator / (double) denominator
    >> 
    >> which is more accurate than what GMP does!

    John> I think that's the right general idea, but "long"
    John> can be 32 bits, and often is; I think you need to
    John> use a system-dependent type that can be guaranteed
    John> to be 64 bits (does Chicken have one?).

Well, we're restricted to the GMP API, which gives us
mpz_fits_slong_p and mpz_get_d but no mpz_fits_double_p or
mpz_fits_long_long_p.  So I believe this is the most
accurate we can hope for in a straightforward manner.

-- 
Alex