ietf-nntp Wildmats

[Clive D.W. Feather]

Charles Lindsey said:
> However, if we decide to do PAT in an XPAT-like fashion, it gets more
> complicate if ',' as 'alternative' gets introduced. A alternative would be
> to introduce an explicit wildmats-separated-by-commas parameter in the
> cases where it was to be allowed. NEWNEWS is the only one that does so at
> present, but there are others where it would make natural sense.

We have wildmats in the following places:

    LIST ACTIVE           - matched against newsgroup names
    LIST ACTIVE.TIMES     - matched against newsgroup names
    LIST DISTRIB.PATS     - (in response) matched against newsgroup names
    LIST NEWSGROUPS       - matched against newsgroup names
    NEWNEWS               - matched against newsgroup names
    PAT                   - matched against header contents

In all except PAT, comma makes sense as alternative. If we provide a way to
escape comma, then we can do the same for PAT and everything becomes much
simpler to describe.

>> (4) Should backslash be allowed to remove the special status of characters
>> other than the four listed ([ * ? and \), or only those four ? If so, which
>> characters ? If not, how do I escape a comma ?
> 
> It does seem usual practice in other specs that backslashing things that
> did not really need backslashing does the 'right thing'.

Not quite: a *lot* of systems treat \<alpha> and \<digit> separately. But I
agree with you for punctuation characters, which would include comma.

I would suggest changing the wording so that:
    \<punct>    escapes that punctuation
    \<alpha>    undefined except as stated ) with the only example for now
    \<digit>    undefined except as stated ) being \u if we include it

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