Hi Irving. That is a very interesting and kind of cool problem.
Happily, Mike Brock who built MVEL, which is part of drools, embeded soundex into it.
So you can do (and I just tried this):
rule "Hello World"
when
c : Cheese( eval(type soundslike "foobar") )
then
c.setPrice(42);
end
And it will match "Cheese" with a type of "fubar" as well. Using soundex standard. You could of course use a function to use some other library that you want, but this is built in.
Note the use of "eval" inside the pattern to indicate it is an expression, not a field constraint.
Hope that helps !
Michael.