Re: [boost] two_pi or pi_twice?

From: Guillaume Melquiond (gmelquio_at_[hidden])
Date: 2002-10-23 13:45:00

On Wed, 23 Oct 2002, Fernando Cacciola wrote:

> > Or should it be the Interval library convention that puts the constant
> > name first - an obvious plus point when making ordered lists - all the
> > pi constants will come together.
> >
> > [details snipped]
> >
> FWIW, my own constants use *exactly* (word by word I think) the naming
> convention you proposed.

Would it be surprising if I said I prefer the way the constants in
the Interval library are named? :)

More seriously, I prefer using a sort of Polish inverse notation in order
to have the main term in front of the name. For example, I think it's more
homogeneous to have

  pi_half
  pi_twice

rather than

  half_pi
  two_pi

> > And while I am seeking views on names, do the following seem sensible:
> >
> > Explicit typed names
> >
> > pi_f // float
> > pi_d // double
> > pi_l // long double or pi_l ??
> > // Potential ambiguity of long int and long double here!
> > // C standard ISO 9899:1999 (a.k.a. C99) choses _l for long double
> > pi_i // integer
> > pi_li // long integer // or pi_l conflists with C99 ??
> >
> What about unsigned constants?

Does that exist? The only unsigned constants that I can think of are the
upper limits of the unsigned integral types. And I don't think the
Constants library has to provide them.

> I'd rather use a 'type + (optional) modifier' postfix scheme:
>
>   type:
>   f=floating point
>   i=integral
>
>   modifiers:
>   s=short
>   l=long
>   u=unsigned
>
> pi_fs (float)
> pi_f  (double)
> pi_fl (long double)
> pi_i  (int)
> pi_il (long int)
> pi_iu (unsigned int)

If you already have 'pi_i', there is no need for 'pi_iu', is it?

> > Interval limit static const constant variable names - add _l and _u
> >
> These will be easely confused with the 'type' postfix.
> I'd use prefix instead:
>
> lower_pi_fl
> higher_pi_fl

I don't know if it's better to have long name. But I'm sure I wouldn't go
for a prefix notation. And I would also use suffixes with the same length:

  pi_fl_lower
  pi_fl_upper

or

  pi_lower_fl
  pi_upper_fl

Please note that 'lower' and 'upper' are the words used to refer to the
bounds of an interval in the Interval library and I think it wouldn't be a
bad idea to use the same notation in the two libraries.

Regards,

Guillaume