[jboss-jira] [JBoss JIRA] Commented: (JBRULES-1460) MVEL parser uses wrong precedence for []

MVEL parser uses wrong precedence for [] ---------------------------------------- Key: JBRULES-1460 URL: http://jira.jboss.com/jira/browse/JBRULES-1460 Project: JBoss Drools Issue Type: Bug Security Level: Public(Everyone can see) Affects Versions: 4.0.4 Reporter: Godmar Back Consider this .drl file: -- package test; import java.util.ArrayList; import java.util.HashMap; dialect "mvel" rule "Rule #1" when then m = new HashMap(); l = new ArrayList(); l.add("first"); m.put("content", l); System.out.println(m["content"][0]); end --- which produces: org.mvel.PropertyAccessException: unable to resolve property: out.println(m["content"][0]) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:285) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccessor(ReflectiveAccessorOptimizer.java:107) at org.mvel.ast.LiteralDeepPropertyNode.getReducedValueAccelerated(LiteralDeepPropertyNode.java:26) at org.mvel.MVELRuntime.execute(MVELRuntime.java:88) at org.mvel.CompiledExpression.getValue(CompiledExpression.java:107) at org.mvel.MVEL.executeExpression(MVEL.java:223) at org.drools.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:47) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:550) at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:514) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:471) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:433) at org.libx.autodetect.DroolsDriver$Host.fireAllRules(DroolsDriver.java:63) at org.libx.autodetect.DroolsDriver.main(DroolsDriver.java:135) Caused by: org.mvel.PropertyAccessException: unable to resolve property: unable to resolve method: java.io.PrintStream.println(java.util.ArrayList, org.mvel.util.FastList) [arglength=2] at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:558) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:257) ... 12 more Exception in thread "main" org.drools.spi.ConsequenceException: org.mvel.PropertyAccessException: unable to resolve property: out.println(m["content"][0]) at org.drools.base.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:14) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:554) at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:514) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:471) at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:433) at org.libx.autodetect.DroolsDriver$Host.fireAllRules(DroolsDriver.java:63) at org.libx.autodetect.DroolsDriver.main(DroolsDriver.java:135) Caused by: org.mvel.PropertyAccessException: unable to resolve property: out.println(m["content"][0]) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:285) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.optimizeAccessor(ReflectiveAccessorOptimizer.java:107) at org.mvel.ast.LiteralDeepPropertyNode.getReducedValueAccelerated(LiteralDeepPropertyNode.java:26) at org.mvel.MVELRuntime.execute(MVELRuntime.java:88) at org.mvel.CompiledExpression.getValue(CompiledExpression.java:107) at org.mvel.MVEL.executeExpression(MVEL.java:223) at org.drools.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:47) at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:550) ... 5 more Caused by: org.mvel.PropertyAccessException: unable to resolve property: unable to resolve method: java.io.PrintStream.println(java.util.ArrayList, org.mvel.util.FastList) [arglength=2] at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:558) at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.compileGetChain(ReflectiveAccessorOptimizer.java:257) ... 12 more but changing: System.out.println(m["content"][0]); to System.out.println((m["content"])[0]); works. (So does assigning m["content"] to a temporary variable.) BTW: if you say that's a MVEL issue, not a Drools issue, consider that I have no other reason to use MVEL than to be able to use Drools. That's why I filed this bug here. I don't know how to run MVEL in any other environment, nor am I interested in it - I'd rather use a mature scripting language (beanshell comes to mind) that doesn't exhibit such basic bugs. Why don't you?