[rules-users] DSL matching return wrong DRL

[Matt Geis]

The question has already been answered, but to help you understand how DSL expansion works, here's what happens.

1.  The expander goes down the list and matches the first expression against all lines in your rules.  So, 

rule dsl2drl_1
when
  Get month summer
then
  Print months;
end

becomes

rule dsl2drl_1
when
  $month: Month(); summer
then
  Print months;
end

2.  The expander tries to match the second expression, and fails.

3.  The expander tries to match the third expression, and succeeds, leaving you with the following DRL.

rule dsl2drl_1
when
  $month: Month(); summer
then
  System.out.println("Month: " + $month.getId());;
end

Looking at the LHS of the rule, this will not compile.


Matt