Re: topological sort

[David Carlisle <davidc@xxxxxxxxx>]

> When I started to think of
> "count(...)=0" as a kind of a NOT, things became a bit clearer.  See
>below.

It's clearer still if you write it as not() rather than using count()


 field[count(type/ref)>0 and ... )

could more clearly be written


field[type/ref and ... )

and

field[count(type/ref)=0 or ...

could be written


field[not(type/ref) or ...


If you use a node set in a boolean contextthen it is true if it is non
empty, so it can be used directly rather than counting it and then
testing the value against 0.

David

_____________________________________________________________________
This message has been checked for all known viruses by Star Internet delivered
through the MessageLabs Virus Control Centre. For further information visit
http://www.star.net.uk/stats.asp


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list