Re: New Functions

> I'm with Martin here.
> Dimitre, are you going overboard with your higher order functions?
> Is it *widely* needed in xSLT/XPATH?


@Dave Pawson <dave.pawson@gmail.com> , Martin's comment was about the
syntax of the function definition (which is now corrected), not about the
usability and need of it.

In fact, I provided one use-case (the for efficient partitioning in the
implementation of the quick-sort algorithm).
Such functions are defined in other languages and not for glossing them...

For a few good examples of the partition function in Haskell, see:
http://zvon.org/other/haskell/Outputlist/partition_f.html

  >  This isn't Lisp.

In the past we used to say: "This isn't Javascript", but the
implementors of Saxon.JS have been learning a lot from Javascript.

In fact, in order to become a good, first-class citizen of the family of
modern programming languages, XPath has a lot to learn from them.

Thanks,
Dimitre

On Mon, Nov 30, 2020 at 1:51 AM Dave Pawson <dave.pawson@gmail.com> wrote:

> I'm with Martin here.
> Dimitre, are you going overboard with your higher order functions?
> Is it *widely* needed in xSLT/XPATH?
>   This isn't Lisp.
>
> regards
>
> On Mon, 30 Nov 2020 at 09:36, Martin Honnen <martin.honnen@gmx.de> wrote:
> >
> > Am 29.11.2020 um 23:53 schrieb Dimitre Novatchev:
> > > Now that we have thetuple/ record type, we can have some very useful
> > > functions on collections (both sequences and arrays) that return more
> > > than one result,
> > > or to say it in other words, return a tuple of Nthings, whereN > 1.
> > >
> > > fn:partition-at($seq as item()*,
> > >
> > >                  $n as xs:integer)
> > >
> > >         as tuple(item()*, item()*)
> >
> > I am having a hard time following the different suggestions and merging
> > them mentally, aren't tuples supposed to have a field name in any case
> > as they are just specialized maps?
> > https://www.saxonica.com/qt4specs/XP/xpath-40-diff.html#id-tuple-test
> >
> > That tuple of N things looks just like an array of (N) things to me.
> >
> > >
> > > , returns a tuple of two sequences, the first of which is
> > >
> > > subsequence($seq, 1, $n), and the second is:
> > >
> > > subsequence($seq, $n +1)
> > >
> >
> > Or how would one access a the first and second field in the result of
> > fn:partition-at($seq, $n)?
> >
> >
> >
> >
> >
>
>
> --
> Dave Pawson
> XSLT XSL-FO FAQ.
> Docbook FAQ.
>
>

-- 
Cheers,
Dimitre Novatchev
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