How to cannonicate numbers in international form

[Tilman Baumann]

Am 17.07.2008 um 22:57 schrieb Werner Almesberger:
>> We could make some blacklist for these known broken countries and  
>> hand
>> crafted code for these irregularities.
>
> I'm not sure how many exceptions you'll need in the end. I would
> expect similar issues to exist in other countries that don't have a
> uniform national numbering plan, except perhaps that "magic" 9.

Well, let's hope not..
>
> Then add fun stuff like carrier selection and such. It does get
> ugly.
Does this exist in the mobile world?
>> But way resort to such methods if the only reason is some crazy  
>> corner
>> case?
>
> You still need it if you want to handle different-length local parts.
> The cost of making it flexible doesn't seem to be be particularly  
> high,
> and you could always use something like "last 7 digits" as the default
> rule.

Sound reasonable.
I just like to strongly oppose to _only_ use some fuzzy match (like  
from right to left). Because there is a major diference in reliability  
for these methods.
A flaky solution like that would only good for matching numbers to  
known numbers from the address book. Not for more.

Transforming local numbers to make them work with any international  
GSM or VoIP provider needs nothing less than a 100% solution.

Regards
  Tilman