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Re: [xsl] following-sibling is evil


Subject: Re: [xsl] following-sibling is evil
From: "Dimitre Novatchev dnovatchev@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Date: Sun, 6 Jul 2014 19:00:44 -0000

> <xsl:if test="following-sibling::Book[Title eq $currentAuthor][Genre eq $currentGenre][1]">

Why not the obviously more-efficient -- especially for a naive
processor that you describe -- code:

    following-sibling::Book[Title eq $currentAuthor and Genre eq
$currentGenre][1]

or probably even better (as a hint to the optimizer):

    exists(head(following-sibling::Book[Title eq $currentAuthor and
Genre eq $currentGenre]))


Certainly, using keys would give us a superior performance, if a more
than one similar expression is evaluated.


-- 
Cheers,
Dimitre Novatchev
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Truly great madness cannot be achieved without significant intelligence.
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To invent, you need a good imagination and a pile of junk
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Never fight an inanimate object
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To avoid situations in which you might make mistakes may be the
biggest mistake of all
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Quality means doing it right when no one is looking.
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You've achieved success in your field when you don't know whether what
you're doing is work or play
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To achieve the impossible dream, try going to sleep.
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Typing monkeys will write all Shakespeare's works in 200yrs.Will they
write all patents, too? :)
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I finally figured out the only reason to be alive is to enjoy it.


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