[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

RE: Variables and constants

Subject: RE: Variables and constants
From: Kay Michael <Michael.Kay@xxxxxxx>
Date: Fri, 25 Feb 2000 14:01:44 -0000
RE: Variables and constants
> This is more of a philosophical question. Since I haven't worked with
> functional programming languages before, can anyone explain to me the
> rationale for not having true variables a'la procedural programming
> languages (i.e. you can re-assign the value of an existing variable)? 

I wasn't involved in the decision, but I've read some of the early working
papers, and as far as I can see the principal rationale was that a language
without side-effects would be capable of incremental rendering, e.g.
starting to display the output before all the input has arrived. I suspect
that in those early days most people expected the language to have a lot
less computational power than it ended up with. The desire to make it
declarative and side-effect free was generally coupled with a
(contradictory) requirement to enable it to call external functions or
scripts.

There is also an argument that a language without side-effects is capable of
a higher degree of optimisation, is less error prone, and so on. The one
argument I haven't seen in anything I've read is any discussion of ease of
use, ease of learning, or (sacrilege) "why not ask the users what they
want?"

Mike Kay


 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list


Current Thread

PURCHASE STYLUS STUDIO ONLINE TODAY!

Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Buy Stylus Studio Now

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Don't miss another message! Subscribe to this list today.
Email
First Name
Last Name
Company
Subscribe in XML format
RSS 2.0
Atom 0.3
Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member
Stylus Studio® and DataDirect XQuery ™are products from DataDirect Technologies, is a registered trademark of Progress Software Corporation, in the U.S. and other countries. © 2004-2013 All Rights Reserved.