Iterable::forEach not returning Iterable

[François Sarradin]

There are monads for these... ;)

francois-
Le 17 mai 2012 16:30, "Rémi Forax" <forax at univ-mlv.fr> a écrit :

> On 05/17/2012 04:05 PM, Brian Goetz wrote:
> > Of course, no one would write production code like this.  Mappers are
> > supposed to be side-effect-free.  But it is an acceptable sin for
> > temporary debugging code.
>
> Haskell guys, please don't read ...
>
> but logging is side effect free until you read the log in the program.
>
> Rémi
>
> >
> > On 5/17/2012 9:26 AM, Remi Forax wrote:
> >> You can use
> >>    map(it ->  {
> >>       Log.log(it);
> >>       return it;
> >>     }).
> >> instead of forEach.
> >>
> >> Rémi
> >>
> >> Sent from my Phone
> >>
> >> ----- Reply message -----
> >> From: "Tomasz Kowalczewski"<tomasz.kowalczewski at gmail.com>
> >> To: "lambda-dev"<lambda-dev at openjdk.java.net>
> >> Subject: Iterable::forEach not returning Iterable
> >> Date: Thu, May 17, 2012 12:33
> >>
> >>
> >> Hi,
> >>
> >> I was trying out the new jdk8 build with lambdas and while doing some
> >> simple towards-lamda-refactoring I stumbled on following use case:
> >>
> >> List<File>  files...
> >> files.filter( File::isFile ).filter( ... ).map(
> >> ConfigurationFile::new );
> >>
> >> I wanted to inject some debugging code inside this chain using forEach
> >> and realized that it returns void and not Iterable. Its default
> >> delegates to Iterables::forEach that returns Interable, so I guess it
> >> is just a matter of deciding if forEach should seal the pipe or allow
> >> more processing.
> >>
> >> Based on my example I think there is a great value in changing the
> >> return type from void as in my opinion it will be harder to debug and
> >> step through such lambdanized code than through several (ugly)
> >> for-each loops doing same work.
> >>
> >> P.S.: Atttaching eclipse debugger to this code being run in a simple
> >> main() instantly crashes the debugged JVM. But I guess debugging is
> >> not yet supported anyway :)
> >>
>
>
>