Re: Ownsoup Pattern Matching

From: Hardy Griech (rgriech@swol.de)
Date: Tue, 27 May 1997 00:14:50 +0100

On Mon, 26 May 1997 15:35:01 -0500, mikus@BGA.COM (Mikus Grinbergs) wrote:
:
> I'm talking about a search pattern that will find articles that do NOT
> have a Message-ID: line. Suppose there WERE a "not" operator ('!' in
> this example) for patterns, then something like the following:
>
> ownsoup -h (^Message-ID)! junk soup

I admit: that's the salt in the VSoup and OwnSoup. There is no real
negation for regular expressions. _Perhaps_ the next release will
have this feature...

BTW, my idea of the syntax is as follows: '!^Message-ID', where the
or-operator '|' binds more than the '!'.

One of the problems to implement the '!' is, that the human being
thinks about it as 'there should be no beginning Message-ID in the
header' and the machine (naive implementation) is thinking 'the
expression evaluates to true, if there is a header line which does not
have a beginning Message-ID.

Big difference, because the second one is a tautology (for standard
news articles of course) and the first one does the intended...

Hardy

PS: Message-ID is not required for successful importing articles to
Yarn newsbased. Date header is enough...

-- 
Hardy Griech, Ernetstr. 10/1, D-77933 Lahr
http://privat.swol.de/ReinhardGriech/