World: r3wp

*check*

But as said, if you have formulars it depends on all input values 
if such an error can happen or not.

After validating the input, you should also put all calculations 
inside one big if error? try [...] and tell the user about overflow. 
It's not that strange! If you get an overflow, you get an error from 
REBOL, and you have ways to handle that, so it doesn't crash.

Ok, but I have about 400 calculations in my app...

So need to go through the complete code and wrap them all.

And those calcs are not one after the other. Scattered throughout 
the program.

I have the same problem with networking operations. programs will 
halt to console if there is a networking error. the only real solution 
is to wrap your calculation code in a function. you could call it 
'calc, and have that return a disarmed error on failure or a number 
or whatever fits to the situation.


This way calc [2 / 0] wouldn't crash to console and it's fairly clean 
to insert.

should read: The only real solution is to wrap your calculation code 
in a block and use that as a function argument. The function could 
be called 'calc.

Rober, liquid is released... do try it out.

(Robert, sorry)

since things are cached, only a value which changes cause any amount 
of processing...

Max, I will but this will need some test and a major rewrite of my 
app. So not for the 1.0 release.

anytime you need help, I'll be happy to give direction...

more demos and tutorials comming shortly

robert, depending on your code, there may be an easier way than put 
try in every calculation; for example if you have a window and do 
the calculation when the user presses a button, you could just use 
try in  the button's action; or, you could wrap the do-events (i.e. 
view) in try, and so on. it also depends on how easy it is to recover 
from a given point (the farther you are from the location of the 
error, the harder it is to recover, usually).

What's the best available XML toolkit available for Rebol these days?

RebXML!? ;-) http://home.tiscali.dk/john.niclasen/rebxml/

Can't be much simpler than that, if simplicity is what you're after.

Looking now :)

Is there a  way to build a rebol object with these tools?

So, I can then identify elements using path notation?

No, not with RebXML as it is now.

Maybe we need rebxml2obj.r and obj2rebxml.r scripts!?

There is a problem with attributes. What if an attribute to a tag 
has the same name as another element within the content of the tag?

A rule could be made, that attributes are placed within a block named 
"attributes" within the object. But that you can't have a tag with 
the name "attributes".

But that = But then

Another solution could be, that attributes and content are treated 
the same, but then something like:
<tag type="mytag"><type>mycontent</type></tag>
will produce:
tab: make object! [type: "mycontent"]
and the attribute is lost.

tab: = tag:

(It's late here. Sorry about misspell.)

perhaps the content should be made an attribute of the tag.

That's a solution, but it can't cope with all XML. What should you 
call the content attribute? You might call it something, that another 
attribute is called already.

Another problem is, that this is valid XML:
<tag1>string 1<tag2>content</tag2>string 2</tag1>


If you made that to an object, how would to refer to "string 1" and 
"string 2"? So of course it's possible to make XML to REBOL objects, 
but then you have to make restrictions to what kind of XML, you can 
handle.

It's hard (maybe impossible) to come up with a solution, that can 
handle all XML.

is there a difference between valid xml and that which is in common 
use?

I don't know. My last example is probably not seen that often, but 
it's valid according to the XML specs.

as long as something covers 80% of the use cases ...

Maybe something can be made from the builtin REBOL parse-xml and 
xml-language?

rebelxml.r looks as though it will do what I need.

cool

http://www.rebol.org/cgi-bin/cgiwrap/rebol/view-script.r?script=rebelxml.r&sid=jp963yh

Graham - I found Gavain's Mckenzie's scripts usefull some two years 
ago. I had also some chat with him, and it seems his work covers 
80% of usual programmer needs. You could build object with his code 
...

I've used Graham's code a lot --especially for hefting RSS files 
into REBOL format. It works well.

There's a HUGE difference between dealing with simple, well formed, 
XML, and trying to implement the XML specification. A good deal of 
XML our there is just well formed; no namespaces, no attributes; 
easy to deal with. I did a loading (XML to blocks) that just makes 
a minor change to parse-xml; it reverses the content and attribute 
values--since attributes are often NONE--so you can use path notation 
on the resulting block.

rebelxml seems to be working so far .. if it doesn't do, I'll look 
at Gavin's stuff again.

>> test: make object! [ a: b: none  c: make object! [ d: none]]
>>
>> obj: make test [ c/d: "testing"]
>> h: make test [ a: 1 ]
>> probe h
make object! [
    a: 1
    b: none
    c: make object! [
        d: "testing"
    ]
]

how come when I create a new test object, it has the same c object 
?  Shouldn't that be a new object as well?

No, when using MAKE, sub-objects are shared (functions are cloned). 
This is how sharing of feel objects is implemented when faces are 
cloned.

So, if you want to be sure to clone your object and every field, 
you will have to check every field to see if it is an object and 
clone it too.

that's a bit painful ... guess why I never used objects much before.

Yes, sharing is handy but not when you don't want it. :)