Re: New Functions

> For 4.0 I'm proposing map:index($seq as item()*, $key as function(item())
as xs:anyAtomicType) which builds a map
> whose keys are the distinct values of the grouping key computed using
$key.
> The proposed partition() function seems to be just a special case of that
where the $key function returns boolean values. (Perhaps group-by would be
a better name than index?)
>
> Michael Kay
> Saxoniica

+1 for "group-by"

We need to be able to use a type variable (generics) instead of item()
and xs:anyAtomicType
.

Thanks,
Dimitre

On Mon, Nov 30, 2020 at 7:40 AM Michael Kay <mike@saxonica.com> wrote:

>
> For a few good examples of the partition function in Haskell, see:
> http://zvon.org/other/haskell/Outputlist/partition_f.html
>
>
>
> For 4.0 I'm proposing map:index($seq as item()*, $key as function(item())
> as xs:anyAtomicType) which builds a map whose keys are the distinct values
> of the grouping key computed using $key. The proposed partition() function
> seems to be just a special case of that where the $key function returns
> boolean values. (Perhaps group-by would be a better name than index?)
>
> Michael Kay
> Saxoniica
>
>

-- 
Cheers,
Dimitre Novatchev
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