On Wed, Feb 16, 2005 at 07:16:50AM +0100, Tomasz Zielonka wrote:
On Wed, Feb 16, 2005 at 04:33:29AM +0000, John Goerzen wrote:
On a related note, Wash seems to be preserving all sorts of unnecessary "state" from previous screens a user visited.
You do know that the current version of WASH rebuilds the continuation by repeating all the previous steps, don't you? Until WASH can keep the
Yes. What I don't understand is why. If I have a submit button, and it is passing one value to the next function, and that value is from an entry form on the screen, why would I care about all the previous state? That's my confusion. It seems unnecessary.
Perhaps you don't see the whole power of continuation based approach to web programming. I will give you an example - when I use WASH, I often pass first-class functions to from screen to screen, for example as a way of telling the screen what to do next (a continuation), or as the most convenient way to do something. It would be quite difficult to pass those functions as form parameters, so they are being rebuilt each time from the log.
Yeah, that's a neat feature. I'm using it some places, too. It's probably true that I don't understand fully how to exploit it yet. (I wish that I could return something other than () from a screen too.) I just want a way to pass only what I need. Passing lots of stuff is going to make my applications painful for modem users, which unfortnuately make up a large part of the user base.
Are you sure your IO actions will always yield the same result? If so, the you can safely use unsafe_io. Otherwise you should let was save the result of them in the log by using io.
Excellent, thanks. -- John