Tabulators -- a catalog

[Raab, Donald]

This is the route we went.  

interface PartitionCollection<T>
{
	Collection<T> getPositive();
	Collection<T> getNegative();
}

More specific than Pair.  Less mutative, flexible and annoying than Collection[].

> -----Original Message-----
> From: lambda-libs-spec-experts-bounces at openjdk.java.net [mailto:lambda-libs-
> spec-experts-bounces at openjdk.java.net] On Behalf Of Brian Goetz
> Sent: Friday, December 28, 2012 10:50 AM
> To: Remi Forax
> Cc: lambda-libs-spec-experts at openjdk.java.net
> Subject: Re: Tabulators -- a catalog
> 
> Seems like overkill :(
> 
> On 12/28/2012 10:46 AM, Remi Forax wrote:
> > On 12/28/2012 04:28 PM, Brian Goetz wrote:
> >> So the thing to do here is return Object[] instead of T[] / D[]. Sad,
> >> but not terrible.  Not important enough to have the user pass in a
> >> factory.  For want of a Pair...
> >
> > The other solution is to send a j.u.List with a specific non mutable
> > implementation able to store only two elements.
> >
> > Rémi
> >
> >>
> >> On 12/28/2012 9:39 AM, Remi Forax wrote:
> >>> On 12/28/2012 03:23 AM, Brian Goetz wrote:
> >>>> Here's a catalog of the currently implemented Tabulators.
> >>>
> >>> [...]
> >>>
> >>>> 3. Partition.  Partitions a stream according to a predicate.
> >>>> Results always are a two-element array of something.  Five forms:
> >>>>
> >>>>     // Basic
> >>>>     <T> Tabulator<T, Collection<T>[]>
> >>>>     partition(Predicate<T> predicate)
> >>>>
> >>>>     // Explicit factory
> >>>>     <T, C extends Collection<T>> Tabulator<T, C[]>
> >>>>     partition(Predicate<T> predicate,
> >>>>               Supplier<C> rowFactory)
> >>>>
> >>>>     // Partitioned mutable reduce
> >>>>     <T, D> Tabulator<T, D[]>
> >>>>     partition(Predicate<T> predicate,
> >>>>               MutableReducer<T,D> downstream)
> >>>>
> >>>>     // Partitioned functional reduce
> >>>>     Tabulator<T, T[]>
> >>>>     partition(Predicate<T> predicate,
> >>>>               T zero,
> >>>>               BinaryOperator<T> reducer)
> >>>>
> >>>>     // Partitioned functional map-reduce
> >>>>     Tabulator<T, T[]>
> >>>>     partition(Predicate<T> predicate,
> >>>>               T zero,
> >>>>               Function<T, U> mapper,
> >>>>               BinaryOperator<T> reducer)
> >>>
> >>> You can't create an array of T (C, D) safely, so casting an array of
> >>> Object to an array of T is maybe acceptable if you control all the
> >>> access to that array like in collections, but here you export it.
> >>>
> >>> Rémi
> >>>
> >