Re: [rules-dev] Constraint efficiency: (was: "New in 5.2.0" - What works, what doesn't?)

On 06/05/2011 07:14, Wolfgang Laun wrote: Edson, On 6 May 2011 01:14, Edson Tirelli <ed.tirelli(a)gmail.com&gt; wrote: > > Wolfgang, > > These are remaining bugs that must be fixed before final. Goal is to > support free form expressions as long as they return a boolean value (for > traditional constraints), or any value (for positional). Period. > (Well, as it's past 5.2.0M2...) Given that any expression is valid, will there still be a distinction w.r.t. efficiency, as there was with traditional constraints as opposed to eval()? If yes, how can I tell whether a constraint expression is "good" or "bad"? Only expressions that are equality constraints on direct fields are currently indexed. Mark One might assume that all legacy forms will be handled as efficiently as now, but it's possible that not only field == ($var + 1) but also field == $var + 1 is efficient. Or, similarly, field == $var and (now) also $var == field But certainly not field - 1 == $var Or, at least, not until some later version ;-) I repeat this quote (from 5.2.0 Drools Introduction and General User Guide) and my question, what does it mean? Where is this "documented"? Is this somehow related to the efficiency issue? <quote> As previously we had to document the restricted limitations of a field constraint on the LHS compared to expressions used inside of an 'eval' or used on the RHS. </quote> Wolfgang > > Edson > > 2011/5/5 Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; > >> In the 5.2.0 Drools Introduction and General User Guide, there's >> section 2.1.3.1, Free Form expressions in Constraints (New Parser). It >> contains several examples: >> #1 Person( age * 2 > $anotherPersonsAge + 2 ) >> #2 Person( addresses["home"].streetName.startsWith( "High Park" ) ) >> #3 Person( isAdult() ) >> >> #1 does not compile: Unable to build constraint as 'age * 2' is invalid >> : [Rule name='exa1'] >> >> #2 works - although I'd very much prefer not to be swamped with MVEL >> extensions unless I ask for it. >> >> #3 does not compile: Unable to Analyse Expression isAdult(): >> [Error: no such identifier: isAdult] >> [Near : {... isAdult() ....}] >> >> Neither rule name nor line number is provided. >> >> Would it please be possible to have a precise statement what one *can*write as a constraint? >> >> >> <quote> >> As previously we had to document the restricted limitations of a field >> constraint on the LHS compared to expressions used inside of an 'eval' or >> used on the RHS. >> </quote> >> >> I'm sorry, but I do not understand the meaning of this sentence. What >> does it mean, please? >> >> Cheers >> Wolfgang >> >> > _______________________________________________ rules-dev mailing listrules-dev@lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-dev _______________________________________________ rules-dev mailing list rules-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-dev