[NNTP] wildmat-exact

[Clive D.W. Feather]

Charles Lindsey said:
> In draft26.pre-1.txt I find
> 
>      wildmat = wildmat-pattern *("," ["!"] wildmat-pattern)
>      wildmat-pattern = 1*wildmat-item
>        ; must not begin with "!" if not immediately preceded by "!"
>      wildmat-item = wildmat-exact / wildmat-wild
>      wildmat-exact = %x21-29 / %x2B / %x2D-3E / %x40-5A / %x5E-7E /
>           UTF8-non-ascii ; exclude * , ? [ \ ]
>      wildmat-wild = "*" / "?"
> and
>      newsgroup-name = 1*wildmat-exact
> 
> So it seems to me that a wildmat-exact (and hence a newsgroup-name) can
> contain (and in particular start with) a '!'.

Yes.

We wanted wildmats to be as general as possible so that they could be used
in other commands in the future. That's why they are allowed to contain
characters like " and !. When we started there was a command that used
wildmats against headers.

On 1st May 2001 you proposed removing it and I said that was "too minimal".
I can't find any further comments in the archives. However, if we're going
to change this from the then-consensus, such as it was, we need to discuss
it first.

> That seems to me to make wildmat ambiguous.

Mu. The point of that comment is to point out how to resolve the ambiguity.
Trying to make the grammar unambiguous just isn't worth the bother. When I
tried to in March 2001 you wrote:

>*You* know that there is a Van Wijngaarden Grammar hiding in there, and
>*I* know that there is a Van Wijngaarden Grammar hiding in there, but for
>the unfortunate masses who do not know, this is just too complicated and
>counterproductive

-- 
Clive D.W. Feather  | Work:  <clive at demon.net>   | Tel:    +44 20 8495 6138
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