Michael,
You are right, eval is more appropriate, but I can't
quite do what I want with eval yet, which is something
like this:
o : MyObject (name == "something")
eval(o.getProp("prop1") == "val1"))
eval(o.getProp("prop2") == "val2"))
2.5 already provides the equivelant of above. I'm
really using the predicate syntax now as a workaround
so that I can have multiple conditions each on its own
line.
Why not just put all expressions in one eval? I
haven't got to the details of DSL, but from what I
have gathered so far, having eval expressions on
separate lines seem to allow more flexible DRL-DSL
mapping. Because we can mix and match the atomic
expressions differently in different rules. For
example, in one rule, we may have
prop1 of MyObject is value1
prop2 of MyObject is value2
prop3 of MyObject is value3
in the other, we may only need
prop1 of MyObject is value1
prop2 of MyObject is value2
These will be mapped to separate eval lines using the
sample DSL statement. If we cannot do multiple evals,
we can't really do that. We will have to instead
create two bigger, un-reusable DSL statements.
Furthermore, does eval have to come at the end of all
conditions? I.e. will we be able to do this?
o : MyObject( name == "something" )
eval (o.getProp("prop1") == "val1")
MyObject( value == "some value" )
When it is all AND relationship among the conditions,
it doesn't really matter, but being able to put the
conditions in any order allows logical groupings of
the conditions, which could make the rule a bit easier
to read.
Thanks for taking the time to answer my questions when
you are busy trying to get the release out. Great job
with 3.0!
Yuesong
--- Michael Neale <[EMAIL PROTECTED]> wrote:
> o : MyObject (name == "something")
> eval(o.getProp("prop") == "val"))
>
> I think will do what you want.
>
> On 4/1/06, Yuesong Wang <[EMAIL PROTECTED]>
> wrote:
> >
> > Hi,
> >
> > I'm doing something like this:
> >
> > o : MyObject (name == "something")
> > MyObject (n : name -> (o.getProp("prop") ==
> "val"))
> >
> > As you can see in the second condition, in order
> to
> > use the predicate constraint, I have to bound an
> > unrelated column. Is there a way to use the
> predicate
> > constraint without the column binding?
> >
> > I know I can use eval, but put everything that is
> not
> > a column in eval can get it really cluttered in a
> > hurry.
> >
> > So I think it will be helper to be able to filter
> the
> > facts based on a non-column, such as:
> >
> > o : MyObejct (name == "something")
> > MyObject( -> (o.getProp("prop") == "val")
> >
> > better yet, without the "->", but I understand if
> > there has to be something to indicate that it is a
> > predicate constraint.
> >
> >
> > Thanks,
> >
> > Yuesong
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam? Yahoo! Mail has the best spam
> protection around
> > http://mail.yahoo.com
> >
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
