Re: [xsl] <quote>XSL is NOT easy</quote>

["Eliot Kimber" <ekimber@xxxxxxxxxxxxxxxxxxx>]

Michael Kay wrote:
> > XSL is NOT easy if 
> > you want to code professionally in it. It IS easy to use XSL 
> > but not well. ....
>
> I would agree with this entirely. But then, I think it's true of every other
> programming language as well. There is an enormous amount of bad
> unmaintainable code being written by self-taught amateur programmers, in all
> sorts of languages, and many of them are attracted to languages like XSLT
> that look easy at first sight.

If by "easy" you mean "the incremental cost of adding or modifying 
functionality stays constant or goes down as code size increases" then I 
would agree that by this measure XSLT is "hard" for the simple reason 
that it lacks the features of object-oriented languages that make them 
"easy" by this measure (re-use via subclassing, interfaces, ability to 
do more or less complete unit testing, deep IDEs for code creation and 
management, generation of code documentation).

XSLT is optimized for more or less direct mappings from input to output 
and for that it is definitely "easier" than doing the same thing in 
something like Java. But as soon as you're trying to do more 
sophisticated data processing it becomes much harder than doing the same 
task in an object-oriented language would be. Not that it can't be done, 
of course, and XSLT 2 makes some things much easier than they were in 
XSTL 1. But XSLT provides no really effective way to implement the sort 
of deep abstractions that make some problems much easier to solve.

In particular, I think a lot of people (myself at one time) assume that 
any processing applied to XML source is best done with XSLT but this is 
clearly not the case, especially when the XML is just a convenient 
serialization format for much more complicated objects rather than a 
representation of a "document" in the generic sense.

Cheers,

Eliot
--
W. Eliot Kimber
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