Re: o:xml arrays ?

Mark,

I don't think that arrays are necessary as first class constructs in 
o:XML - but I could be wrong!
There is a core type for representing two-dimensional arrays called 
Table, and a (not yet finished) Array type for n-dimensional arrays. 
They can both be implemented using 'normal' arrays in the target 
language, ie Table is implemented in ObjectBox using Java arrays.
In XPath you can retrieve the x-th node of a nodeset with '[x]', which 
is a predicate but looks and mostly acts as array operators in other 
languages. My intention with the Array type is to allow access to array 
elements or sub-arrays in the same way, eg:
<o:set array="Array(3,3)"/> <!-- produce a 3x3 array -->
<o:set subarray="$array[1]"/><!-- get the first row -->
<o:set element="$array[1][1]"/><!-- get the first element -->

The types provide an extensible, polymorphic interface to lower-level 
language constructs such as arrays, which I think is more useful than 
direct language support. For example the Array type can include matrix 
manipulation functions like transpose, invert etc. Java or C arrays are 
powerful and efficient but not very practical to work with - similar 
maybe to pointers.

If you use the Java language extensions, there are ways of converting 
Java arrays to Lists, and to produce Java arrays from o:XML. I intend 
to improve this by integrating Java extensions with the Array type in 
the future.

hope this answers your question, regards,

/m

On 23 Jul 2004, at 13:42, Mark Horowitz wrote:

>
> are arrays a current, future, or nonexistent part of o:xml ?
>
> mark horowitz
> a.s.a., scjp
> towers perrin
>


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