<h1 style="font-weight: normal;" class="title"><font size="2"><a id="d0e1">In the 5.2.0 Drools Introduction and General User Guide</a>, there's section 2.1.3.1, Free Form expressions in Constraints (New Parser). It contains several examples:</font><br>
</h1>#1 Person( age * 2 > $anotherPersonsAge + 2 ) <br>#2 Person( addresses["home"].streetName.startsWith( "High Park" ) )<br>#3 Person( isAdult() )<br><br>#1 does not compile: Unable to build constraint as 'age * 2' is invalid : [Rule name='exa1']<br>
<br>#2 works - although I'd very much prefer not to be swamped with MVEL extensions unless I ask for it.<br><br>#3 does not compile: Unable to Analyse Expression isAdult():<br>[Error: no such identifier: isAdult]<br>[Near : {... isAdult() ....}]<br>
<br>Neither rule name nor line number is provided.<br><br>Would it please be possible to have a precise statement what one <i>can</i> write as a constraint?<br><br><br><quote><br><a id="d0e371">This was also important for us to start to move towards a
single consistent grammer for both the "when" left hand side and "then"
right hand side.<br></quote><br><br>It seems that example #2 increases the grammar gap because the constraint expression can certainly not used on the RHS.<br><br><br><quote><br></a><a id="d0e371">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.</a><a id="d0e371"><br> </quote><br><br>I'm sorry, but I do not understand the meaning of this sentence. What does it mean, please?<br><br>Cheers<br>Wolfgang<br>
<br><br></a>