Re: o:XML Syntax

Hi Dave,

Thanks for the kind words!

Firstly to answer your question regarding expressions vs XML constructs 
-
o:XML was designed to be fairly easy to type and use as a 'normal' 
language (compare XSLT), as well as being easy to process. Effectively 
the result is a compromise between these requirements. The dot notation 
follows on from the decision to use XPath as an integral part of the 
language, combined with OO requirements.
Using XPath/o:Path provides a very powerful means of manipulating XML 
that I think is worth the added complexity of an unparsed expression 
language - o:XML wouldn't be the same without o:Path.
I've been working on an intermediate XML format that has no unparsed 
expressions - see
http://www.o-xml.org/projects/mlml.html
MLML can much more easily be translated into another language - 
especially other dynamically typed languages.

2) If using MLML: Support libraries implementing the o:XML core types 
in the target language, and a transformation stylesheet. Otherwise also 
need expression parsing.
If the target language is statically typed, then dynamic function 
dispatch has to be implemented (as with Java).

3) There are currently no plans on changing the license, however a 
commercial license could be provided on demand.

4) Currently no. You can set the log level, eg debug/warning, but not 
the output target. It's a good idea though, could you pls add it to 
bugzilla as a feature request -> 
http://bugz.pingdynasty.com/enter_bug.cgi

> Instead of having to supply the same SQL information for every call, 
> is it possible to set it once (defaults) then have particular 
> instances override the destination data store as required?

I'm afraid I don't quite understand. Are you referring to the 
connection details? Or db:query params? The latter could allow default 
values, but I don't think they currently do. Something for the next 
release maybe.
Also I'd like to refactor the db extensions to make the object model 
available to programmers, to access Connection, Query objects etc, and 
implement transaction blocks and rollbacks properly.

thanks for the mail and support!

/m

On 24 Aug 2004, at 22:04, Dave Jarvis wrote:

> Hello,
>
> I have a few simple questions about o:XML, mostly from items I've 
> noticed in other, related constructs (including JavaML and XSL).
>
> Before I get into my questions, I would like to say that I'm really 
> impressed on how wonderfully SQL has been integrated into the 
> language.  I, myself, have done such language constructs in the past, 
> but didn't hit anything that felt nearly as clean or well-designed. 
> Kudos.
>
> 1. What was the driving force behind including the dot notation?
>
> Additionally, what would it take to move the interpreter from a dot 
> notation to something completely uninfluenced by target language?  
> Consider:
>
> <o:return select="$ling.translate( 'hello' )" />
>
> Compared with the JavaML form:
>
> <o:return>
> 	<o:value-of target="ling" message="translate">
> 		<o:param>hello</o:param>
> 	</o:value-of>
> </o:return>
>
> I realize the first way is succinct (and possibly faster to 
> interpret), yet it seems more difficult to transform into non-C-based 
> languages (e.g., Smalltalk).
>
> 2. What would be required to transform o:XML into languages such as 
> Smalltalk, Python, or Ruby?
>
> 3. I noticed the license is GPL.  Are there plans to move the 
> licensing to LGPL?
>
> 4. With respect to logging and SQL calls, is there a 'global' area 
> where a person can set the targets?  For example, if I wanted to log 
> to a specific file for 90% of the code, but to a console (e.g., 
> System.out) for the other 10%, would it be difficult?  The same for 
> SQL, of course.
>
> Instead of having to supply the same SQL information for every call, 
> is it possible to set it once (defaults) then have particular 
> instances override the destination data store as required?
>
> Sincerely,
> Dave Jarvis
> -- 
> Invoq Systems Inc.
> t. 250.380.0304
> w. http://www.invoqsystems.com
> _______________________________________________
> o-xml mailing list
> o-xml-zRfLyl9bSvv/[email protected]
> http://lists.pingdynasty.com/mailman/listinfo/o-xml
>


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