Re: [xsl] differences between x != 0 and not(x = 0)

["G. Ken Holman" <gkholman@xxxxxxxxxxxxxxxxxxxx>]

At 2005-06-08 10:03 -0400, Jaime Stuardo wrote:
> If I want to test that all nodes has value different from 0, I have to
> use x!=0 or not(x=0) ?

Use not(x=0) to return true if all of the values are not equal to 0.  The 
processor will walk through each node in set "x" and continue checking as 
long as the answer is false.  "x=0" is false if x is non-zero, so it keeps 
checking the nodes in x.  As soon as any is true, the comparison stops and 
true is returned, and the not() changes the true to false.  If all of the 
tests are false, then false is returned and not() changes the false to 
true, implying that all of the nodes are not equal to zero because none of 
the nodes are equal to zero.

But be aware of what you want for the empty set "x", though.  Do you want 
true or false?  The comparison is initialized to false so if there are no 
nodes in "x" the comparison returns false and the not() returns true and 
you will get "all nodes different from 0" when you have no nodes ... you 
may not want that.

I hope this helps.

. . . . . . Ken


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