Aside from the DataSet issue, I also found an inconsistency with the Java
API. In Java join is done as:

ds1.join(ds2).where(...).equalTo(...)

where in the current Scala this is:

ds1.join(d2).where(...).isEqualTo(...)

isEqualTo() should be renamed to equalTo(), IMO.
Also, join (+cross and coGroup?) lacks the with() method because "with" is
a keyword in Scala. Should be offer something similar for Scala or go with
map() on Tuple2(left, right)?

2014-09-08 13:51 GMT+02:00 Stephan Ewen <[email protected]>:

> Instead of Strings, Object[][] would work as well. That is a generic
> representation of a Tuple.
>
> Alternatively, they could be stored as Java or Scala Tuples, with a generic
> utility method to convert between the two.
>
> On Mon, Sep 8, 2014 at 10:55 AM, Fabian Hueske <[email protected]> wrote:
>
> > Yeah, I ran into the same problem...
> >
> > +1 for using Strings and parsing them,  but using the CSVFormat won't
> work
> > because this is based on a FileInputFormat.
> > So we would need to parse the Strings manually...
> >
> > 2014-09-08 10:35 GMT+02:00 Aljoscha Krettek <[email protected]>:
> >
> > > Hi,
> > > on second thought. Maybe we should just change all the example input
> > > data to strings and use CSV input formats in all the examples. What do
> > > you think?
> > >
> > > Cheers,
> > > Aljoscha
> > >
> > > On Mon, Sep 8, 2014 at 7:46 AM, Aljoscha Krettek <[email protected]>
> > > wrote:
> > > > Hi,
> > > > yes it's unfortunate that the data types are incompatible. I'm afraid
> > > > you have to to what you proposed: move the data to a static field and
> > > > convert it in the getDefaultEdgeDataSet() method in Scala. It's not
> > > > nice, but copying would duplicate the data and make it easier for it
> > > > to go out of sync in the Java and Scala versions.
> > > >
> > > > What do the others think? This will probably occur in all the
> examples.
> > > >
> > > > Cheers,
> > > > Aljoscha
> > > >
> > > > On Sun, Sep 7, 2014 at 10:04 PM, Vasiliki Kalavri
> > > > <[email protected]> wrote:
> > > >> Hey,
> > > >>
> > > >> I have ported the Connected Components example, but I am not sure
> how
> > to
> > > >> reuse the example input data from java-examples.
> > > >> In the ConnectedComponentsData class, the vertices and edges data
> are
> > > >> produced by the methods getDefaultVertexDataSet()
> > > >> and getDefaultEdgeDataSet(), which take
> > > >> an org.apache.flink.api.java.ExecutionEnvironment as parameter.
> > > >>
> > > >> One way is to provide public static fields (like in the
> WordCountData
> > > >> class), but this introduces a conversion
> > > >> from org.apache.flink.api.java.tuple.Tuple2 to Scala tuple and from
> > > >> java.lang.Long to scala.Long and I guess this is an unnecessary
> > > complexity
> > > >> for an example (?).
> > > >> Another way is, of course, to copy the example data in the Scala
> > > example.
> > > >>
> > > >> Am I missing something here?
> > > >>
> > > >> Thanks!
> > > >>
> > > >> Cheers,
> > > >> V.
> > > >>
> > > >>
> > > >> On 5 September 2014 15:52, Aljoscha Krettek <[email protected]>
> > > wrote:
> > > >>
> > > >>> Alright, I updated my repo:
> > > >>> https://github.com/aljoscha/incubator-flink/commits/scala-rework
> > > >>>
> > > >>> This now has a working WordCount example. It's pretty much a copy
> of
> > > >>> the Java example with some fixups for the syntax and lambda
> > functions.
> > > >>> You'll also notice that I added the java-examples as a dependency
> for
> > > >>> the scala-examples. I did this to reuse the example input data.
> > > >>>
> > > >>> When you ported a program you can do a pull request against my repo
> > > >>> and I will collect the examples.
> > > >>>
> > > >>> Happy coding. :D
> > > >>>
> > > >>> On Fri, Sep 5, 2014 at 12:19 PM, Hermann Gábor <
> [email protected]
> > >
> > > >>> wrote:
> > > >>> > +1
> > > >>> >
> > > >>> > ComputeEdgeDegrees for me!
> > > >>> >
> > > >>> >
> > > >>> > On Fri, Sep 5, 2014 at 11:44 AM, Márton Balassi <
> > > >>> [email protected]>
> > > >>> > wrote:
> > > >>> >
> > > >>> >> +1
> > > >>> >>
> > > >>> >> BatchGradientDescent for me :)
> > > >>> >>
> > > >>> >>
> > > >>> >> On Fri, Sep 5, 2014 at 11:15 AM, Kostas Tzoumas <
> > > [email protected]>
> > > >>> >> wrote:
> > > >>> >>
> > > >>> >> > +1
> > > >>> >> >
> > > >>> >> > I go for WebLogAnalysis.
> > > >>> >> >
> > > >>> >> > My experience with Scala consists of going through a tutorial
> so
> > > this
> > > >>> >> will
> > > >>> >> > be a good stress test both for me and the new API :-)
> > > >>> >> >
> > > >>> >> >
> > > >>> >> > On Thu, Sep 4, 2014 at 9:09 PM, Vasiliki Kalavri <
> > > >>> >> > [email protected]>
> > > >>> >> > wrote:
> > > >>> >> >
> > > >>> >> > > +1 for having other people implement the examples!
> > > >>> >> > > Connected Components and Kmeans for me :)
> > > >>> >> > >
> > > >>> >> > > -V.
> > > >>> >> > >
> > > >>> >> > >
> > > >>> >> > > On 4 September 2014 21:03, Fabian Hueske <
> [email protected]>
> > > >>> wrote:
> > > >>> >> > >
> > > >>> >> > > > I go for TriangleEnumeration and PageRank.
> > > >>> >> > > >
> > > >>> >> > > > Let's also do the examples similar to the Java examples:
> > > >>> >> > > > - running out-of-the-box without parameters
> > > >>> >> > > > - parameters for external data
> > > >>> >> > > > - follow a similar code structure
> > > >>> >> > > >
> > > >>> >> > > >
> > > >>> >> > > >
> > > >>> >> > > > 2014-09-04 20:56 GMT+02:00 Aljoscha Krettek <
> > > [email protected]
> > > >>> >:
> > > >>> >> > > >
> > > >>> >> > > > > Will do, then people can reserve their favourite
> examples
> > > here.
> > > >>> >> > > > >
> > > >>> >> > > > > On Thu, Sep 4, 2014 at 8:55 PM, Fabian Hueske <
> > > >>> [email protected]>
> > > >>> >> > > > wrote:
> > > >>> >> > > > > > Hi,
> > > >>> >> > > > > >
> > > >>> >> > > > > > I think having examples implemented by different
> people
> > > >>> proved to
> > > >>> >> > be
> > > >>> >> > > > > > valuable in the past.
> > > >>> >> > > > > > I'd help with two or three examples.
> > > >>> >> > > > > >
> > > >>> >> > > > > > It might be helpful if you'd port a simple first one
> > such
> > > as
> > > >>> >> > > WordCount.
> > > >>> >> > > > > >
> > > >>> >> > > > > > Fabian
> > > >>> >> > > > > >
> > > >>> >> > > > > >
> > > >>> >> > > > > > 2014-09-04 18:47 GMT+02:00 Aljoscha Krettek <
> > > >>> [email protected]
> > > >>> >> >:
> > > >>> >> > > > > >
> > > >>> >> > > > > >> Hi,
> > > >>> >> > > > > >> I have a working rewrite of the Scala API here:
> > > >>> >> > > > > >>
> > > >>> >>
> https://github.com/aljoscha/incubator-flink/commits/scala-rework
> > > >>> >> > > > > >>
> > > >>> >> > > > > >> I'm hoping that I'll only have to write the tests and
> > > port
> > > >>> the
> > > >>> >> > > > > >> examples. Do you think it makes sense to let other
> > people
> > > >>> port
> > > >>> >> the
> > > >>> >> > > > > >> examples, so that someone else uses it and maybe
> > notices
> > > some
> > > >>> >> > quirks
> > > >>> >> > > > > >> in the API?
> > > >>> >> > > > > >>
> > > >>> >> > > > > >> Cheers,
> > > >>> >> > > > > >> Aljoscha
> > > >>> >> > > > > >>
> > > >>> >> > > > >
> > > >>> >> > > >
> > > >>> >> > >
> > > >>> >> >
> > > >>> >>
> > > >>>
> > >
> >
>

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