I was the one implementing the FP approach to original GridGain APIs. As Dmitriy mentioned - with Java 8 a lot of this is no longer necessary or desirable. Furthermore, in retrospect trying to mimic FP style in non-FP Java was a futile exercise and led to some APIs becoming unwieldy. I think we can safely deprecate (most of) this over time.
For those looking for FP-style APIs: - either use Java 8 rudimentary support, - or use Groovy for slightly better FP support, - or use Clojure or Scala for a full FP support. All languages above can natively use all Ignite APIs. For example, in Scala only a small set of implicit conversions is required to have pretty fluid FP usage pattern (look at Scalar DSL for more examples). -- Nikita Ivanov ​GridGain founder​ On Thu, May 7, 2015 at 11:58 AM, Konstantin Boudnik <c...@apache.org> wrote: > On Thu, May 07, 2015 at 09:32AM, Dmitriy Setrakyan wrote: > > On Thu, May 7, 2015 at 8:54 AM, Sergey Evdokimov < > sevdoki...@gridgain.com> > > wrote: > > > > > Hello, > > > > > > I have some suggestions for improvement utility classes. > > > > > > 1.) We have big class org.apache.ignite.internal.util.lang.GridFunc > that > > > has a lot of methods in 8000 lines. I propose to split it to several > > > classes where utility methods are group by purpose. For example > methods to > > > work with IgnitePredicate should be in IgnitePredicates class, methods > to > > > work with Iterator should be in IgniteIterators class, etc... Same > grouping > > > is used in Guava. > > > > > > 2.) Methods like GridFunc.not(IgnitePredicate p) must not return > anonymous > > > class, it should return class with correct name. When I debug code and > see > > > to value of variable I cannot understand that is "GridFunc$123", > something > > > like "GridFunc$PredicateNot" looks much better. > > > > > > 3.) Methods with ugly signature like GridFunc.iterator(Iterable c, > > > IgniteClosure trans, boolean readOnly, @Nullable IgnitePredicate<? > super > > > T1>... p) should be split to simple methods like > > > "GridFunc.transform(Iterable itr, IgniteClosure trans)", > > > GridFunc.filter(Iterable itr, IgnitePredicate p), > > > GridFunc.readonly(Iterable c) > > > > > > Thoughts? > > > > > > > GridFunc is a legacy class that should be deprecated in my view. It comes > > from the previous life when we were adding functional abstracts to Java. > > Obviously, with Java 8 it is not needed. > > Which brings an interesting question: shall we plan for dropping Java7 > support > as it was OEL'ed? > > > My suggestion would be to start by cleaning up GridFunc and removing all > > the methods that are not currently used. Then we can see how we can > > refactor the methods that are in use. > > > > D. >
