[Python-Dev] trunc()

[Jeffrey Yasskin]

On Jan 25, 2008 5:53 AM, Paul Moore <p.f.moore at gmail.com> wrote:
> On 24/01/2008, Jeffrey Yasskin <jyasskin at gmail.com> wrote:
> > int has to be a builtin because it's a fundamental type. trunc()
> > followed round() into the builtins. I have no opinion on whether ceil
> > and floor should move there; it probably depends on how often they're
> > used.
>
> Suggestion:
>
> - int() has to stay in builtins for obvious reasons.
> - put *all* of trunc, ceil, floor, round into math.
> - make int(float) an error

I'd deal with Facundo's objection that you should be able to convert
between builtin datatypes without the use of a module by leaving trunc
in the builtins, but it looks like I'm in the minority here. If the
decision comes to be that int(float) should be blessed as a correct
way to truncate a float, I'd agree with Raymond that trunc() is just
duplication and should be eliminated. I'd, of course, rather have a
spelling that says what it means. :)

> The only fly in the ointment is that 2to3 can't handle the semantic
> issues around converting int(n) to math.trunc(n) because it can't
> detect the type of n. So why not make int(float) warn in -3 mode on
> 2.6, and then let 2to3 do the conversion (on the basis that 2to3
> should only be run on code that is -3 warning free)?

I'd be happy with that too.

-- 
Namasté,
Jeffrey Yasskin