Re: ispolygonal

[Karim Belabas <Karim.Belabas@math.u-bordeaux1.fr>]

* Bill Allombert [2012-05-09 16:15]:
> On Wed, May 09, 2012 at 02:20:52PM +0200, Karim Belabas wrote:
>> The rationale was to avoid the e_MISC error type [ which is essentially
>> impossible to trap cleanly ], and consider that the expected input
>> "type" was 'a t_INT in Z_{> 2}'.
>> 
>> This is a bit far-fetched and potentially confusing, I temporarily changed
>> it to e_MISC.
>> 
>> Presumably we need a general error type for "violated inequality" ?
>> 
>>   pari_err(e_INEQ, "ispolygonal", "s > 2", s);
> 
> We could define
> pari_err(e_TOOSMALL,"ispolygonal",s,gen_2)
>     --> "%s: %Ps must be > %Ps"
> In practice I expect this would cover almost all case and allow the user
> to retrieve the inequality.

We might need

  e_TOOSMALL (must have s > ...)
  e_TOOLARGE (must have s < ...)
  e_BADVALUE (must have s != ...)

In fact, I'd expect the last one (BADVALUE) to be the most common (0 in
arithmetic functions, poles of transcendental functions, etc.).

The second one might not be needed at all since e_OVERFLOW might cover
all existing cases.

Cheers,

    K.B.
-- 
Karim Belabas, IMB (UMR 5251)  Tel: (+33) (0)5 40 00 26 17
Universite Bordeaux 1          Fax: (+33) (0)5 40 00 69 50
351, cours de la Liberation    http://www.math.u-bordeaux1.fr/~belabas/
F-33405 Talence (France)       http://pari.math.u-bordeaux1.fr/  [PARI/GP]
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