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

[Andrew Gierth]

>>>>> "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.

In existing code, there is no way to include spaces in wildmats _at
all_ (they are after all never needed for group-matching wildmats, so
that only leaves XPAT; as far as I know, those clients that use XPAT
substitute whitespace and other unacceptable characters with '?' and
do their own post-matching on the results). This is clearly not
optimal, which is one reason I looked at adding general \-escapes (so
that \040 or \x20 (or \u0020) could be used for literal spaces).

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.

-- 
Andrew.