Re: [xsl] summing up incrementally

Subject: Re: [xsl] summing up incrementally
From: Paul Tremblay <phthenry@xxxxxxxxxxxxx>
Date: Fri, 19 Dec 2003 14:56:18 -0500
On Fri, Dec 19, 2003 at 02:10:57PM -0000, Michael Kay wrote:
> > 
> > WOOPS! 
> > 
> > Of course, 103 + 102 + 108 = 313! 
> > 
> > Okay, I need to minus the 100:
> > 
> > 1938 = 03 + 02 = 05
> > 
> > 1939 = 03 + 02 + 08 = 13
> > 
> Your maths is not your strong point - have you never heard of compound
> interest? You actually need the product 1.03 * 1.02 * 1.08.

What a jerky thing to say from an author! My percentage is a bit rusty
because I don't use it every day. Once my mistake was pointed out, I
understood exactly what I did wrong.

A few months ago I wrote that Michael Kay had written that the largest
document you can process is a few megabytes. You wrote back that you
never said that. I thought I was mistaken, so I looked up the fact in
your book. I politely pointed this out. Here is the thread: 

Paul Tremblay: 

	Michale Kay in his book mentions that documents larger
	than 1 or 2 MB cannot be processed by an XSLT processor, because, as you
	say, the processor loads them into memory.

other poster: 

	Did he really say that?  That would surprise me, because
	that limit seems rather low.
Michael Kay: 

	It would surprise me too, but anything is possible.

Paul Tremblay: 

	I thought I was mistaken. But here is the quote:   

	 "One caveat about data conversion applications: today's XSLT 
	 processors all rely on holding the data in memory while the 
	 transformation is taking place. The tree structure in memory 
	 can be as much as ten times the original data size, so in 
	 practice, the limit on data size for an XSLT conversion is a 
	 few megabytes. Even at this size, a complex conversion can be   
	 quite time-consuming, it depends very much on the processing 
	 that you actually want to do."(p. 45. Kay, Michael, *XSLT 2nd 
	 edition. Programmer's Reference*: Arden House, Birmingham,    
	 Acock's Green, Canada, Wrox Press, 2001.)

Michale Kay:

	You may have read "a few" as meaning "1 or 2", but that's not what I
	wrote. I was suggesting the heuristic "if you've got a 64Mb machine
	don't try to process more than about 6Mb of source data."

At the time I thought "What an evasive reply!" In the book you wrote
nothing about a "heuristic," but stated that XSLT could only process
small documents. You did not state any relationship between
memory and document size. You simply said a document can be only a "few"
megabytes in size. 

I would be surprised if anyone would interpret a "few" as more than 3. If
you said "I have a few muffins--do you want one?" And then you opened
your cabinet to show 10, I think your guest would be surprised. If you
said that you wrote an application that requires only a few megabytes of
memory, and that few ended up being 5 or 10, you might have an angry

But I didn't say anything. I thought, well, Kay is the expert, and it is
nice of him to spend his time answering questions.

But apparently you have a bit of a problem with human interaction.

By the way, since we are being jerky, let me quote a sentence from the
passage above: "Even at this size, a complex conversion can be quite
time-consuming, it depends very much on the processing that you actually
want to do." You did realize this was a run-on sentence, didn't you?

I am sorry to react so strongly. I guess I expect the stupid insults
from computer people on emails from time to time. I would not expect it
from an expert.



*Paul Tremblay         *

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