ietf-nntp Wildmats

[Charles Lindsey]

In <ylpue2qzo8.fsf at windlord.stanford.edu> Russ Allbery <rra at stanford.edu> writes:


>Charles Lindsey <chl at clw.cs.man.ac.uk> writes:
>> Andrew Gierth <andrew at erlenstar.demon.co.uk> writes:
>>>>>>>> "Clive" == Clive D W Feather <clive at demon.net> writes:

>>> Clive> [W6: the grammar does not treat , in sets as special. This
>>> Clive> means that the wildmat "a[b,c]d" is a single pattern that
>>> Clive> matches the three strings "abd", "a,d", and "acd". Are we
>>> Clive> happy with this ? It matches existing practice


>> Then, in the second place, wildmats have (apart from XPAT) only ever
>> been used to match newsgroup names (and this will remain true). Since
>> ',' cannot occur within a newsgroup name (for obvious reasons) it is
>> impossible for this case ever to have arisen in the past; nor will it
>> ever arise under our present proposal.

>Just because ',' cannot occur in a newsgroup name doesn't prevent a user
>from sending a pattern with a wildmat set containing a comma.  If they did
>so, it would be treated as Andrew describes.

But there would be no point in a user doing such a thing, so we should not
care overmuch.

If OTOH you are concerned that it might arise when people use XPAT as
currently implemented, then there may be a problem, and forbidding
"a[b,c]d" would be the way to solve it. Do existing implementations
currently flag that case as an error?

It really depends how kind we want to be to continued use of XPAT. I think
we agree that it should be allowed to die and be replaced by something
better (e.g. using proper REs), but no doubt its death will be prolonged.

-- 
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