Re: Perfomance: 'conditional instruction' vs. 'multi

look like priority attribute can help in some cases - you can give
higher priority for frequent cases and lower priority for rare cases

i think in many cases power of using tunnel variables and next-match
underestimated by developers too

in many cases using other mode (even if it not necessary by logic)
help for speed also

2012/11/4 Daniel Sullivan <dsullivan@xxxxxxxxx>:
> I agree doing code in smaller pieces is usually better. I was just following
Ken's terms of declarative and imperative to refer to things the same way he
was.
>
> But in XSLT you can, in effect override a part of a monolithic method, i.e.
template.
>
> If the importing stylesheet has something like:
>
> <template match="thenode[child::x]">
>    ... do_this ...
> </template>
>
>
> And the imported stylesheet has something like:
>
> <template match="thenode">
>    <xsl:choose>
>    <xsl:when test="x">
>      ... do_this ...
>
>   </xsl:when>
>    <xsl:otherwise>
>      ... do_that ...
>   </xsl:otherwise>
> </xsl:choose>
> </template>
>
> Then when the xml being processed has an <thenode><x/></thenode>, thenode
will be processed by the importing stylesheet.
>
> And a node like <thenode><a/></thenode> will be processed by the imported
stylesheet.
>
> So you can override parts of a monolithic template.
>
> I'm not saying it's a good thing to do, just that it is a very handy
technique when you have to use a stylesheet that you are not allowed to
change.
>
> Dan
>
> -----Original Message-----
> From: Michael Kay [mailto:mike@xxxxxxxxxxxx]
> Sent: Saturday, November 03, 2012 4:04 PM
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: Re:  Perfomance: 'conditional instruction' vs. 'multi
template'
>
>
> On 03/11/2012 18:42, Daniel Sullivan wrote:
>> But templates in the importing stylesheet that match have absolute priority
over those in the imported stylesheet, so a declarative stylesheet that
imports another stylesheet would have the same effect whether the imported
stylesheet was declarative or imperative, wouldn't it?
>>
>>
> The point is that if you split your code into smaller templates, then you
can override smaller parts of your code. It's the same as in OO programming -
big monolithic methods can only be overridden in-toto, you can't change parts
of their behaviour selectively.
>
> Incidentally, the terms "declarative" and "imperative" for describing this
distinction are not really very appropriate. Arguably everything in XSLT is
declarative. It's just that some constructs look more imperative than others -
especially those like choose and apply-templates and format-number that are
expressed using imperative English verbs.
>
> Michael Kay
> Saxonica