The use of AND in source pattern of accumulate causes compilation error in executable model.

Solution Unverified - Updated -


Building a rule written in MVEL dialect like (*1) using AND in source pattern of accumulate like (*1-1) in executable rule model, a compilation error (*2) occurs.

(*1) rule

package com.example.reproducer

import java.math.BigDecimal

dialect "mvel"

rule "rule7a2"
        $total : BigDecimal() from accumulate( $car : Car( discontinued == true ) and Order( item == $car, $price : price ), // ..... (*1-1)
                                               init( BigDecimal total = BigDecimal.ZERO; ),
                                               action( total += $price; ),
                                               reverse( total -= $price; ),
                                               result( total ) )
        System.out.println("***** Action of rule7a2 -- $total = " + $total);


$ mvn clean compile exec:exec -DgenerateModel=YES
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile-1) @ reproducer_model_compiler_7a ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 13 source files to /work2/testdir/reproducer_model_compiler_7a/target/classes
[INFO] -------------------------------------------------------------
[INFO] -------------------------------------------------------------
[ERROR] /work2/testdir/reproducer_model_compiler_7a/target/generated-sources/drools-model-compiler/main/java/com/example/reproducer/[28,63] method accumulate in class org.drools.model.DSL cannot be applied to given types;
  required: org.drools.model.view.ViewItem<?>,org.drools.model.functions.accumulate.AccumulateFunction,org.drools.model.functions.accumulate.AccumulateFunction[]
  found: org.drools.model.view.ViewItem
  reason: cannot infer type-variable(s) T
    (actual and formal argument lists differ in length)
[INFO] 1 error
[INFO] -------------------------------------------------------------

This issue does not occur when we build the rule with executable model disabled.


  • Red Hat Decision Manager (RHDM)
    • 7.1.0 - 7.10.0

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