Continuation based behavior of web pages might make sense to a Scheme
programmer, but since when did it square with real user expectations or
past experience?
How many times have you make a money transfer on an online banking
page, or submitted a bid on an eBay auction, or sent an email message
with web mail, or ordered a book from Amazon?
When you hit the back button, you would never expect a transaction to
be undone, because in all experience it never happens that way, because
it simply wouldn't make any sense in the real world.
People understand how web servers and transactions work, because they
use them every day, and people understand that time moves forward
without cause and effect jumping backwards like a Dr. Who time travel
epsidoe.
A web server that used continuations in the way people are discussing
would violate the principle of least astonishment, and that's simply
bad user interface design, no matter how much it resembles a cool
programming language's obscure but powerful flow control structure.
http://en.wikipedia.org/wiki/Principle_of_least_astonishment
That is why well written web sites make their pages refresh when you
press the back button, and the servers are purposefully programmed not
to accept the same form submission twice.
It's standard operating procedure: try it with any online banking site
or eBay, and see what happens.
There is no online banking site on earth that will undo a money
transfer when you press the back button, and for good reason.
Any web site that did that would astonish and confuse users (if not
make them very rich and put the bank out of business ;), because most
users aren't scheme programmers, and expect the effects of what they've
done to persist, and expect time to move forward without skipping
around.
-Don
Tom Barta wrote:
[
Re: Abominations of nature (and flagrant violation of the Principle of Least Astonishment),
David Given
RE: Abominations of nature (and flagrant violation of the Principleof Least Astonishment), Richard Ranft
- References:
- Re: Features you would like to see, Mark Hamburg
- Re: Features you would like to see, David Given
- Re: Features you would like to see, Alex Queiroz
- Re: Features you would like to see, David Kastrup
- Abominations of nature (was: Features you would like to see), David Given
- Re: Abominations of nature (was: Features you would like to see), Fabien
- Re: Abominations of nature (was: Features you would like to see), Roberto Ierusalimschy
- Re: Abominations of nature (was: Features you would like to see), Alex Queiroz
- Re: Abominations of nature (was: Features you would like to see), Roberto Ierusalimschy
- Re: Abominations of nature, David Given
- Re: Abominations of nature, Tom Barta