[rules-dev] Functional programming in Drools: java 5 minimum with java 8 support

[Wolfgang Laun]

Another alternative would be to freeze one Drools version as "last one for
Java 5", and proceed undauntedly to new shores. But there is also the issue
of suppor - don't know whether you buy a guarantee of unlimited progress
towards new features while standing still at some Java version.

Also: Providing DRL features that are only available with Java 6/7/8... will
make documentation even more of a maze as it is now.

-W

On 20 October 2011 13:49, Geoffrey De Smet <ge0ffrey.spam at gmail.com> wrote:

> **
> The minimum java version we require (currently java 5)
> need not be the same as the maximum java version language features we
> support.
>
> For example, drools 6 could require at least java 5 to run, but
> - if source>=7 and target>=7 you can use switch(String) and other coin
> stuff in DRL functions
> - if source>=8 and target>=8 you can use closures in DRL functions
> The point is... drools-core source code itself can't use that stuff (unless
> it's in the extension module drools-core-jdk7).
>
> Spring 2.0.0 did something similar IIRC: it required at least JDK 1.4, but
> if it detected JDK 1.5 you could use annotations too.
>
> Note: despite all that, I still wish we move the minimum java version to 6
> :)
>
> Op 20-10-11 13:26, Wolfgang Laun schreef:
>
> Last time Mark asked, there was a huge outcry - some people using some Java
> that's standing still at Java 5.
> -W
>
> On 20 October 2011 13:21, Toni Rikkola <toni.rikkola at gmail.com> wrote:
>
>> I would also like to keep it as close to Java as possible.
>>
>> There are few problems here:
>> * It could never go beyond Java
>> * We are using Java 5 and just considering Java 6, this would be a huge
>> leap :-)
>>
>>  But then again if we don't use the Java way, then what will we do when
>> Drools reaches Java 8, support both?
>>
>>  Toni
>>
>>  On Oct 20, 2011, at 11:08 AM, Geoffrey De Smet wrote:
>>
>>  Interesting stuff.
>> This is basically
>>   "closures" which will be available in JDK 8
>>   + LHS closure pattern support
>>
>> 1) About "closures" which will be available in JDK 8:
>> Since functions contain Java code, which is imperative, not declarative, I
>> don't consider that DRL turf any more.
>> *Our closure syntax should there should be exactly the same as Java 8.*
>> Here's their syntax, which looks the same on first sight, but the devil is
>> in the details (= unreleased spec):
>>
>> http://mail.openjdk.java.net/pipermail/lambda-dev/2011-September/003936.html
>> Either we wait for JDK 8 to be released to support closures (current
>> release date is 2012 according to Mark R.'s "plan B" that released JDK 7 in
>> 2011)
>> or we implement it just like the JDK8 with the exact same syntax (which is
>> a LOT of work).
>>
>> 2) About LHS closure pattern support.
>> This builds on top of 1) to allow usage of closures in the LHS.
>> Cool stuff, I like the piping idea.
>>
>> Op 19-10-11 23:12, Mauricio Salatino schreef:
>>
>> Hi Mario, that document looks great.. I will take some time to read it and
>> I will try to give some feedback.
>> I was playing with cypher (from neo4j, a graph oriented DB) (total newbie
>> on that) but looking at your in line acc functions I think that we can take
>> some concepts from cypher and apply them in DRL.
>> Cheers
>>
>> On Wed, Oct 19, 2011 at 5:59 PM, Mario Fusco <mario.fusco at gmail.com>wrote:
>>
>>> Hi all,
>>>
>>> as anticipated by Mark, I put down some ideas on how we could start
>>> introducing some functional programming features in the DRL.
>>>
>>> http://community.jboss.org/wiki/FunctionalProgrammingInDrools
>>>
>>> It's needless to say that the document has to been considered just a
>>> draft in its very first stage and any feedback or suggestion to improve or
>>> clarify it is welcome.
>>>
>>> Mario
>>>
>>> _______________________________________________
>>> rules-dev mailing list
>>> rules-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-dev
>>>
>>>
>>
>>
>>  --
>>  - CTO @ http://www.plugtree.com
>>  - MyJourney @ http://salaboy.wordpress.com
>> - Co-Founder @ http://www.jugargentina.org
>>  - Co-Founder @ http://www.jbug.com.ar
>>
>>  - Salatino "Salaboy" Mauricio -
>>
>>
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>>
>>
>> --
>> With kind regards,
>> Geoffrey De Smet
>>
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>
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>
> --
> With kind regards,
> Geoffrey De Smet
>
>
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