RE: Re: [xsl] Vendor extensions for XSLT - higher order functions

[cknell@xxxxxxxxxx]

You do yourself a favor when you listen to criticism, especially well-intentioned criticism from a source with experience in the field.
-- 
Charles Knell
cknell@xxxxxxxxxx - email



-----Original Message-----
From:     Dimitre Novatchev <dnovatchev@xxxxxxxxx>
Sent:     Mon, 23 Jul 2007 06:52:36 -0700
To:       xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject:  Re: [xsl] Vendor extensions for XSLT - higher order functions

> FXSL, unfortunately, is so powerful that I think many "ordinary" users find
> it rather daunting. A gentler introduction, using examples from the world of
> commercial IT systems rather than computer science, would help to sell it to
> the general public.

There is nothing so powerful in FXSL and it implements some most basic concepts.

Concepts like: fold, map, compose, repeat/iterate   -- form the
alphabet of programming.

Certainly, if someone has arrived at grade 5 in school and still
doesn't know the alphabet, this person will find reading even ordinary
text rather "daunting".

To summarize, FXSL provides a big potential to learn, requires
learning, and this is even a bigger value than simply the provided
functionality.


-- 
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play

On 7/21/07, Michael Kay <mike@xxxxxxxxxxxx> wrote:
> > I am curious to know why some XSLT vendors have implemented
> > one or more XSLT extension functions with their product to
> > make for the implementation of higher-order functions (HOF) in XSLT.
>
> In the case of Saxon, it was needed by an XQuery user, and availability in
> XSLT was just a spin-off. It's not possible to use the FXSL approach in
> XQuery because it relies on xsl:apply-templates. In fact, this kind of
> capability is needed much more in XQuery because even without FXSL, there
> are many things you can do with xsl:apply-templates to handle dynamic
> content that have no simple solution in XQuery.
>
> In fact, in business applications I far more often see the need for
> saxon:evaluate() (in both XSLT and XQuery) where expressions are constructed
> at run-time from strings. But saxon:evaluate() is easy to understand, and it
> often gets used to solve problems where compile-time higher-order functions
> would be a cleaner and more efficient solution.
>
> FXSL, unfortunately, is so powerful that I think many "ordinary" users find
> it rather daunting. A gentler introduction, using examples from the world of
> commercial IT systems rather than computer science, would help to sell it to
> the general public.
>
> Michael Kay
> http://www.saxonica.com/