you no longer need to declare custom accumulators, instead they are specified via imports. See docs, notice the “import” bit. Accumulate CE (preferred syntax)


The code for the function is very simple, as we could expect, as all the "dirty" integration work is done by the engine. Finally, to use the function in the rules, the author can import it using the "import accumulate" statement:

import accumulate <class_name> <function_name>

For instance, if one implements the class some.package.VarianceFunction function that implements thevariance function and wants to use it in the rules, he would do the following:

On 5 Mar 2014, at 23:13, mattmadhavan <> wrote:

I am still suck on Drools 5.4/5.5 since I have issues with Custom
operators/Evaluators in 5.6.

I am not able to move to Drools 6.x because the spring configuration is
screwed up. There is no option to configure Custom operator/Evaluators in

Looks like I just cannot move to 6.x because most of my rules are highly
dependent on the Custom operator/evaluator I created!

I am mighty confused.

Any ideas?


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