[rules-dev] accumulate to acc

[Mark Proctor]

On 18/08/2011 18:17, Wolfgang Laun wrote:
> On 18 August 2011 18:38, Mark Proctor <mproctor at codehaus.org 
> <mailto:mproctor at codehaus.org>> wrote:
>
>     We are looking to tighten up accumulate, using a new keyword to
>     differentiate. It will use ; for separation, to follow a similar
>     form to
>     a 'for' loop.
>
>     acc( CE*;
>     <func>*;
>     <guard>? )
>
>     so something like:
>
>     acc( $o : Order();
>             $min : min( $o.value ),
>             $max : max($o.value);
>             $min > 100 && $max < 100 )
>
>
> Given that I can do this today using an eval after the accumulate CE: 
> What's the big gain, as compared to the nuisance of yet another CE, 
> with the need to document (which, traditionally, isn't done so 
> eagerly) and teach and learn and getting it free of bugs?
I find the above looks cleaner and easier to read, the more we can 
reduce the need for 'eval' the better. It is a common enough use case 
that I feel it is worth support. Acc is used a lot for CEP use cases and 
we need a syntax that can compete succinctly with alternative approaches 
- if we look like a dog dinner, we'll lose out to alternative CEP 
syntaxes. The separation of the segments using ";" gives a clearer 
distinction too, and it's 'for' loop like nature should more natural to 
people new to the engine.

Mark
>
> -W
>
>
>     I have wondered if we could use pipes on our functions, to be able to
>     pass the results of one function into another - just not sure how that
>     will work or look yet.
>     func(...) in func(...)
>     func(...) | func(...)
>
>     Mark
>
>     _______________________________________________
>     rules-dev mailing list
>     rules-dev at lists.jboss.org <mailto:rules-dev at lists.jboss.org>
>     https://lists.jboss.org/mailman/listinfo/rules-dev
>
>
>
>
> _______________________________________________
> rules-dev mailing list
> rules-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-dev/attachments/20110818/8dc01352/attachment.html