wildmats (was: Re: ietf-nntp Draft summary of IETF 48 meeting)

[Charles Lindsey]

In <87snsfd14v.fsf at erlenstar.demon.co.uk> Andrew Gierth <andrew at erlenstar.demon.co.uk> writes:


>>>>>> "Stan" == Stan Barber <sob at academ.com> writes:

> Stan> Clarification of wildmat usage in various commands

> Stan> There has been some discussion about how to deal with compound
> Stan> wildmats versus multiple wildmats. The group decided that
> Stan> commas can be used to link together wildmats to form a compound
> Stan> wildmat. A space would separate multiple wildmats.  Spaces can
> Stan> be embedded in a wildmat if preceded by a backslash.

>absolutely not. This breaks all attempts to parse the command into a
>parameter list prior to interpreting it; the command parser would need
>to know which parameters are wildmats and which are not. Much existing
>server code depends on being able to split parameters on whitespace
>alone.

Agreed. In the XPAT command (see the Common Extensions draft) you parse
the parameters as a succession of wildmats, and then (in code specific to
the XPAT command) you stick them together separated by to-be-recognised
whitespace (for whether the PAT command has this same behaviour, see my
separate message).

>As for commas, to the best of my knowledge no existing implementation
>supports the use of compound wildmats using commas except in relation
>to specific commands (i.e. NEWNEWS) where the syntax explicitly states
>so. Therefore this would be an incompatible change to existing
>practice.

Nevertheless, I agree that this is a generalization too useful not to have
in. Apparently some implementations do it already. I could live with a
situation where clients operating with old implementations might have to
refrain from using the enhanced functionality. No existing behaviour would
be broken AFAICS.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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