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World: r3wp

[Core] Discuss core issues

Anton
22-Jul-2009
[14306]
In R2 View, Alt is not supported. If you look at the event datatype, 
there are fields only for control and shift.
Pekr
22-Jul-2009
[14307]
ah, my bad, Anton is right ....
ChristianE
22-Jul-2009
[14308]
Robert, you're mentioning Excel, so you're probably trying to do 
ALT+RETURN hard line-breaks with Excel thru comlib?

Maybe you can use the actual character code that Excel uses whenever 
one presses Alt+Enter. The web says Excel just inserts a line feed 
#"^/", have you tried that?
Gabriele
23-Jul-2009
[14309]
Alt+RETURN is not a character
Robert
23-Jul-2009
[14310]
Christian, right, I try to insert a hard line-break in Excel. I tried 
inserting NEWLINE, which doesn't work. Will try just the LN. Thanks.
Graham
27-Jul-2009
[14311]
Apart from chucking an error, what is the best way to determine if 
a path exists inside an object?  So, the path might be 10 deep ...
Sunanda
27-Jul-2009
[14312]
As far as I know, Graham, there is not a simpler way than provoking 
an error.
If you are already at the bottom of the structure FIND can help:

    a: make object! [b: make object! [c: 1]]
    find next first a/b 'd     ;; is a/b/d valid?
    == none
    find next first a/b 'c     ;; is a.b.c valid?
   == [c]


But recursing to the bottom may be slower than just trying the error?:
   error? try [a/b/d]
   error? try [a/b/c]
Graham
27-Jul-2009
[14313]
Seems ugly to have to use an error ...
Anton
27-Jul-2009
[14314]
It's a poorly specified way of obtaining some information.
Henrik
27-Jul-2009
[14315]
perhaps there is merit for a feature to quickly determine the existence 
of a deeply stored value?
Graham
27-Jul-2009
[14316x3]
can't even do this

in object 'path/to/rebol
because 'in expects a word
How is this done in R3 ??
BrianH
27-Jul-2009
[14319x2]
Same as in R2:
in object/path/to 'rebol
The problem is that at some point the field names can turn into function 
refinements, depending on the values assigned...
Anton
27-Jul-2009
[14321x4]
And why is that such a problem?
I mean, it's a solvable problem. IN could theoretically be enhanced 
to also accept paths, but, iIrc, Carl wasn't keen on the idea because 
he wanted IN to remain simple and fast. He said something like "it's 
for words".
The only thing we can do is make our own mezz version of IN that 
accepts paths.
(Ok, it's not a solvable problem for paths with dynamic elements 
in them like functions, but of course, there are many more "static" 
paths which this would be darned useful for.)
BrianH
27-Jul-2009
[14325]
GET and SET work with paths in R3. Perhaps as you describe could 
be added as well, to handle the IN function for paths. And functions 
wouldn't be traced through.
Graham
27-Jul-2009
[14326]
the problem with object/path/to 'rebol is that it assumes object/path/to 
exists
BrianH
27-Jul-2009
[14327x3]
Yup.
So you have to check for 'to in object/path first, and so on. I didn't 
say it would be a fast mezzanine :(
The way this kind of thing is resolved in R3 is through liberal use 
of the ASSERT/type function, and not representing XML as objects.
Graham
27-Jul-2009
[14330x2]
I guess there's a lot of advantages to just using blocks ... as it 
is now, some elements in my object are blocks and some are objects 
which makes it very messy
OTOH, blocks could get messy too ...


at present I have structures like ccr/body/alerts/alert where alert 
can be either a single alert object, or a block of alert objects

Ideally if I were to use blocks, it would end up that alert is always 
a block .. 0 ... n blocks
BrianH
27-Jul-2009
[14332]
The R3 GUI is structured as a mix of objects, maps, blocks and gobs, 
but it is very consistent and not messy.
Graham
27-Jul-2009
[14333]
I presume it can't change though ... if a particular item is an object!, 
it won't be a block of objects in another instance ....
BrianH
27-Jul-2009
[14334]
very consistent
, yes :)
Graham
27-Jul-2009
[14335]
That's my issue ... because the standard for the data has not been 
tightly defined, there are varying implementations leading to somewhat 
variable structures
BrianH
27-Jul-2009
[14336]
Sounds like you need a tighter definition, or to resign yourself 
to slow code.
Graham
27-Jul-2009
[14337]
It's an ASTM standard ... I can't change the XSD!
BrianH
27-Jul-2009
[14338]
But you can use a consistent REBOL representation of it, and don't 
need objects.
Graham
27-Jul-2009
[14339]
Google health has solved the issue by only working with a subset 
of the XSD.
BrianH
27-Jul-2009
[14340]
Well, you can clean it up to a usable structure on read, process 
it nicely, then regenerate the bad XML on write.
Graham
27-Jul-2009
[14341x2]
Yeah .. I guess I was getting to that.
I suspect this is a very common issue and not bad xml.  So, if the 
XSD states an element can be 0 ... n and each element can be of a 
different type, then it's going to be difficult to work with no matter 
what.
BrianH
27-Jul-2009
[14343]
If an XSD states that; it should always be a block even in the single 
object case.
Graham
27-Jul-2009
[14344]
I guess the xml-to-object.r script doesn't know that!
BrianH
27-Jul-2009
[14345x4]
I never liked that script :(
(no offence intended to whoever wrote it)
Saw a new language the other day that has a native, literal data 
structure which matches the XML object model, without the syntax.
Nice language - clean and small, pretty to look at, compiles to native 
code.
Graham
27-Jul-2009
[14349x3]
Given 


>> obj: make object! [ Description: make object! [ Text: "REBOL" 
]]
>> path: 'Description/Text
== Description/Text


How can I find "REBOL" without breaking the path into it's constituents?
I'm guessing that there's something very simple ... but in the meantime


get-value: func [ obj [object!] path [path!]
	/local id
][
	if not empty? path [
		either all [ id: in obj path/1  obj: get id  object? obj ][
			remove path
			get-value obj path
		][
			obj
		]
	]
]
>> get-value obj path
== "REBOL"
Ashley
29-Jul-2009
[14352x2]
Is this a bug or a feature:

>> to integer! ""
== 0
>> to decimal! ""
** Script Error: Invalid argument:
** Near: to decimal! ""
Henrik
29-Jul-2009
[14354]
R3 returns a bug with the first one, but it could be intentional 
in both R2 and R3.
BrianH
29-Jul-2009
[14355]
It was an intentional change. TO has been cleaned up a lot in R3 
- the error there tells why:
>> to integer! ""
** Script error: content too short (or just whitespace)