Iterable::forEach not returning Iterable

[Brian Goetz]

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.

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 :)
>