Re: [cdi-dev] Adding Lambdas as CDI beans

Sven, I'm a little curious, why do they need to avoid serializable contexts? In all honesty, I use app scoped functions, predicates in my code, at least in a couple of places. Lambdas are specifically meant for operations, not data, so they should be in a highly reusable scope (in my opinion at least). On the flip side, I have a hard time justifying needing to provide injectable beans for lambdas since good encapsulation should indicate they're only used in a single spot. John On Sat, Oct 17, 2015 at 7:51 AM Sven Linstaedt <sven.linstaedt(a)gmail.com&gt; wrote: > Just one question: Who is on charge and is able of managing this > unmanaged instances, e.g. lifecycle, serialization, concurrency (e.g. when > dealing with closures)? > > Functional programming and DI seem to be somehow disjunct in this case. > E.g. manually setting up observers seem to better fit extension than normal > application code. > > On the other side, specifying producer methods or fields, that are > injectable and return lambda expressions seems to be a no brainier for CDI, > is not it? As long as they are not scoped in a serializable context. > > Have a nice weekend > Sven > > -- sent by phone > > Am 17.10.2015 um 11:06 schrieb David Blevins <david.blevins(a)gmail.com&gt;: > > In brainstorming mode about fun that could be made possible with Java 8 > and Java EE. > > Question in my mind is: is there some way we could make it possible for > Lambdas or Method Refs to be CDI beans? > > It goes against the grain obviously as CDI creation is very much a “Don’t > call us, we’ll call you” kind of thing. The VM dynamically creates a > wrapper object around the Lambda or method reference and it implements the > given interface. > > To make it work, there would need to be some non-producer method way of > saying “put this thing in the context with these qualifiers”. > > Imagine a method somewhere that would allow you to: > > public <T> void addObserver(java.util.function.Consumer<T> observer, > Annotation... qualifiers); > > > Then you could take advantage as follows: > > final List<URI> uris = new ArrayList<>(); > // @Observes URI > addObserver((Consumer<URI>) uris::add); > > // @Observes Thread > addObserver(Runtime.getRuntime()::addShutdownHook); > > // @Observes Runnable > addObserver((Consumer<Runnable>) > Executors.newFixedThreadPool(3)::submit); > > // @Observes URI > addObserver((Consumer<URI>) System.out::println, new > AnnotationLiteral<Fine>() { > }); > > // @Observes Handler > final Logger logger = Logger.getLogger("somewhere"); > addObserver(logger::addHandler); // add handlers via event > > // @Observes @Fine String > addObserver((Consumer<String>) logger::fine, new > AnnotationLiteral<Fine>() {}); > } > > > > -David > > > > -- > David Blevins > http://twitter.com/dblevins > http://www.tomitribe.com > > _______________________________________________ > cdi-dev mailing list > cdi-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/cdi-dev > > Note that for all code provided on this list, the provider licenses the > code under the Apache License, Version 2 ( > http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas > provided on this list, the provider waives all patent and other > intellectual property rights inherent in such information. > > _______________________________________________ > cdi-dev mailing list > cdi-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/cdi-dev > > Note that for all code provided on this list, the provider licenses the > code under the Apache License, Version 2 ( > http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas > provided on this list, the provider waives all patent and other > intellectual property rights inherent in such information. _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 ( http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information.