Re: Understanding score syntax

[David Z Maze]

currentlyeddie@rogers.com writes:

> From the manual:
>
> ("xref"
>   ("[^:\n]+:[0-9]+ +[^:\n]+:[0-9]+ +[^:\n]+:[0-9]+"
>    -1000 nil r)))
>
> What, exactly is going on here? I'm especially fuzzy on the 0-9 bits. I
> put this in all.SCORE, and it began lowering scores on messages posted
> to a favorite newsgroup that don't seem to be crossposted.

It's fundamentally a regular expression, and regexps are used in lots
of parts of Emacs and Un*x in general (and perl and python and sed and
...), so they're definitely useful to lear about.  Dissecting it:

[^:\n]+            At least one of any character except colon or newline
:                  A colon
[0-9]+             At least one digit
 +                 At least one space
[^:\n]+:[0-9]+ +   Similarly
[^:\n]+:[0-9]+     Similarly

So it matches headers with values like

gnu.emacs.gnus:1234 alt.fan.lars-magne-ingebrigtsen:567 comp.editors.xemacs:17

That is, with at least three clauses in the Xref: header.

  --dzm