Re: XSLT 4: Define proper streaming

  On Mon, May 25, 2020 at 10:13 PM Martin Honnen martin.honnen@xxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

>  Are there any such designs or implementations in terms of the XDM?



Not that I know of, but it is possible to express any tree - processing
using a 2-dimensional fold - like function.

See the *foldtree* function as defined by John Hughes in "Why functional
programming matters" (p. 7):

https://www.cs.kent.ac.uk/people/staff/dat/miranda/whyfp90.pdf

Although this particular example isn't strictly a left fold (a left fold is
tail-recursive and can be implemented without recursion) , it is possible
to write a left-fold-tree function -- see for example:

https://stackoverflow.com/questions/52451923/variations-of-folds-on-haskell-trees




Cheers,
Dimitre



On Mon, May 25, 2020 at 10:13 PM Martin Honnen martin.honnen@xxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> Am 25.05.2020 um 22:00 schrieb Dimitre Novatchev dnovatchev@xxxxxxxxx:
> > This one should be obvious enough:
> >
> > In XSLT 3.0 only a source XML document can be streaming -processed.
> >
> > Why not an output of a (potentially other/unknown/external/independent)
> > transformation?
>
> I think you can chain two or more streaming transformations with Saxon
> EE, at least from the host language like Java and s9api or even relying
> on SAX APIs. Not sure whether it is also possible using fn:transform.
>
>
> > Please, don't tell us that we don't know how to exactly formulate this
> > requirement, or that it is ("extremely") difficult to implement it. Both
> > a possible design and implementation are delivered in the concept of a
> > **concurrent queue**.
>
> Are there any such designs or implementations in terms of the XDM?