Re: JESS: Is it possible to bind a Java object directly to a Jess variable without creating a new object?
Use shadow facts.
see http://www.jessrules.com/jesswiki/view?FactsVsShadowFacts
On Nov 4, 2011, at 1:08 PM, Hunter McMillen wrote:
Hi everyone,
I am trying to assert to Jess that an object exists when I encounter a new
object in my Java program. Right now I am using a template to mirror that
object (i.e I have slot values for all of the Java objects fields) but this
seems redundant to me. Is there any way to just bind a Java object to a Jess
variable without creating a new Java object?
A lot of the examples I see online and from JIA are of the form:
(bind ?map (new HashMap))
or
(call Classname method params...)
but these either create a new object or call static methods. I already have
the Java object and just want to store it.
But I was hoping that there was someway I could do something like this:
public Rete engine = new Rete();
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.executeCommand((bind ?unit unit));
engine.executeCommand((assert ?unit));
}
Or would I have to use the store() and fetch() methods for this?
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.store(UNIT, unit);
engine.executeCommand((bind ?unit (fetch UNIT));
engine.executeCommand((assert ?unit));
}
Basically I want to know the best practice for binding Java objects to Jess
variables so I can assert them to the engine.
Thanks,
Hunter McMillen
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Re: JESS: Is it possible to bind a Java object directly to a Jess variable without creating a new object?
Thanks for your quick reply. After I manage to get my Java object into
Jess, can I assert it as a fact? Then have rules lhs match on the existence
of some object with attributes x, y, and z?
Hunter
On Fri, Nov 4, 2011 at 4:01 PM, Friedman-Hill, Ernest ejfr...@sandia.govwrote:
**
There are (obviously) two options: (a) put the object somewhere
accessible, and run Jess code that retrieves it, or (b) use Jess's Java API
to set a Jess variable to contain the object. Either would work. The
store/fetch mechanism is sort of an built-in easy way to do (a).
Alternatively, say there's a global variable ?*x* defined in your Jess
program. Then you can say
engine.getGlobalContext().setVariable(*x*, new Value(unit));
and your Jess code can later get the value of *x*.
If you don't like using variables this way, there's always directly
invoking Jess functions from Java. Here we invoke 'add' to add the object
to working memory directly:
new Funcall(add, engine).arg(new
Value(unit)).execute(engine.getGlobalContext());
--
*From:* owner-jess-us...@sandia.gov [mailto:owner-jess-us...@sandia.gov] *On
Behalf Of *Hunter McMillen
*Sent:* Friday, November 04, 2011 1:08 PM
*To:* jess-users
*Subject:* JESS: Is it possible to bind a Java object directly to a Jess
variable without creating a new object?
Hi everyone,
I am trying to assert to Jess that an object exists when I encounter a
new object in my Java program. Right now I am using a template to mirror
that object (i.e I have slot values for all of the Java objects fields)
but this seems redundant to me. Is there any way to just bind a Java
object to a Jess variable without creating a new Java object?
A lot of the examples I see online and from JIA are of the form:
(bind ?map (new HashMap))
or
(call Classname method params...)
but these either create a new object or call static methods. I already
have the Java object and just want to store it.
But I was hoping that there was someway I could do something like this:
public Rete engine = new Rete();
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.executeCommand((bind ?unit unit));
engine.executeCommand((assert ?unit));
}
Or would I have to use the store() and fetch() methods for this?
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.store(UNIT, unit);
engine.executeCommand((bind ?unit (fetch UNIT));
engine.executeCommand((assert ?unit));
}
Basically I want to know the best practice for binding Java objects to
Jess variables so I can assert them to the engine.
Thanks,
Hunter McMillen
RE: JESS: Is it possible to bind a Java object directly to a Jess variable without creating a new object?
That's what Rete.add() and Rete.definstance() do. If that's the goal, all of
this other stuff is superfluous -- just call add() or definstance() from Java.
From: owner-jess-us...@sandia.gov [mailto:owner-jess-us...@sandia.gov] On
Behalf Of Hunter McMillen
Sent: Friday, November 04, 2011 7:50 PM
To: jess-users
Subject: Re: JESS: Is it possible to bind a Java object directly to a Jess
variable without creating a new object?
Thanks for your quick reply. After I manage to get my Java object into Jess,
can I assert it as a fact? Then have rules lhs match on the existence of some
object with attributes x, y, and z?
Hunter
On Fri, Nov 4, 2011 at 4:01 PM, Friedman-Hill, Ernest
ejfr...@sandia.govmailto:ejfr...@sandia.gov wrote:
There are (obviously) two options: (a) put the object somewhere accessible, and
run Jess code that retrieves it, or (b) use Jess's Java API to set a Jess
variable to contain the object. Either would work. The store/fetch mechanism is
sort of an built-in easy way to do (a). Alternatively, say there's a global
variable ?*x* defined in your Jess program. Then you can say
engine.getGlobalContext().setVariable(*x*, new Value(unit));
and your Jess code can later get the value of *x*.
If you don't like using variables this way, there's always directly invoking
Jess functions from Java. Here we invoke 'add' to add the object to working
memory directly:
new Funcall(add, engine).arg(new
Value(unit)).execute(engine.getGlobalContext());
From: owner-jess-us...@sandia.govmailto:owner-jess-us...@sandia.gov
[mailto:owner-jess-us...@sandia.govmailto:owner-jess-us...@sandia.gov] On
Behalf Of Hunter McMillen
Sent: Friday, November 04, 2011 1:08 PM
To: jess-users
Subject: JESS: Is it possible to bind a Java object directly to a Jess variable
without creating a new object?
Hi everyone,
I am trying to assert to Jess that an object exists when I encounter a new
object in my Java program. Right now I am using a template to mirror that
object (i.e I have slot values for all of the Java objects fields) but this
seems redundant to me. Is there any way to just bind a Java object to a Jess
variable without creating a new Java object?
A lot of the examples I see online and from JIA are of the form:
(bind ?map (new HashMap))
or
(call Classname method params...)
but these either create a new object or call static methods. I already have
the Java object and just want to store it.
But I was hoping that there was someway I could do something like this:
public Rete engine = new Rete();
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.executeCommand((bind ?unit unit));
engine.executeCommand((assert ?unit));
}
Or would I have to use the store() and fetch() methods for this?
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.store(UNIT, unit);
engine.executeCommand((bind ?unit (fetch UNIT));
engine.executeCommand((assert ?unit));
}
Basically I want to know the best practice for binding Java objects to Jess
variables so I can assert them to the engine.
Thanks,
Hunter McMillen
Re: JESS: Is it possible to bind a Java object directly to a Jess variable without creating a new object?
I daresay, not all of us use the same terms for the same things ;-)
I'll use Pojo for a Java object; it contains data in named fields. I'll
use Fact for an entitiy that has been inserted into Jess' Working Memory;
it contains data in named slots. And then, there is a shadow fact, which
is a fact with a reference to a Pojo in a slot that is (by definition)
called OBJECT; slot values are taken from the object's fields of the same
name.
Quote: I am trying to assert to Jess that an object exists when I
encounter a new object in my Java program.
Comment: In any case, this must be done by creating/inserting a fact. As
has been said, a shadow fact is the easiest way to do this; it's defined
from the backing class, and it is inserted by adding the Pojo. Creating an
equivalent fact implies that all slots must be filled, by hand-coded code,
from the Pojo; there's no further connection between these two, which is
bound to cause additional details.
Quote: Is there any way to just bind a Java object to a Jess variable
without creating a new Java object?
Comment: This is not the same thing as asserting to Jess. You can bind a
Pojo to a Jess variable without inserting/asserting it. But this variable
will not affect the firing of rules.
-W
On 5 November 2011 00:49, Hunter McMillen mcmil...@gmail.com wrote:
Thanks for your quick reply. After I manage to get my Java object into
Jess, can I assert it as a fact? Then have rules lhs match on the existence
of some object with attributes x, y, and z?
Hunter
On Fri, Nov 4, 2011 at 4:01 PM, Friedman-Hill, Ernest
ejfr...@sandia.govwrote:
**
There are (obviously) two options: (a) put the object somewhere
accessible, and run Jess code that retrieves it, or (b) use Jess's Java API
to set a Jess variable to contain the object. Either would work. The
store/fetch mechanism is sort of an built-in easy way to do (a).
Alternatively, say there's a global variable ?*x* defined in your Jess
program. Then you can say
engine.getGlobalContext().setVariable(*x*, new Value(unit));
and your Jess code can later get the value of *x*.
If you don't like using variables this way, there's always directly
invoking Jess functions from Java. Here we invoke 'add' to add the object
to working memory directly:
new Funcall(add, engine).arg(new
Value(unit)).execute(engine.getGlobalContext());
--
*From:* owner-jess-us...@sandia.gov [mailto:owner-jess-us...@sandia.gov]
*On Behalf Of *Hunter McMillen
*Sent:* Friday, November 04, 2011 1:08 PM
*To:* jess-users
*Subject:* JESS: Is it possible to bind a Java object directly to a Jess
variable without creating a new object?
Hi everyone,
I am trying to assert to Jess that an object exists when I encounter a
new object in my Java program. Right now I am using a template to mirror
that object (i.e I have slot values for all of the Java objects fields)
but this seems redundant to me. Is there any way to just bind a Java
object to a Jess variable without creating a new Java object?
A lot of the examples I see online and from JIA are of the form:
(bind ?map (new HashMap))
or
(call Classname method params...)
but these either create a new object or call static methods. I already
have the Java object and just want to store it.
But I was hoping that there was someway I could do something like this:
public Rete engine = new Rete();
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.executeCommand((bind ?unit unit));
engine.executeCommand((assert ?unit));
}
Or would I have to use the store() and fetch() methods for this?
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.store(UNIT, unit);
engine.executeCommand((bind ?unit (fetch UNIT));
engine.executeCommand((assert ?unit));
}
Basically I want to know the best practice for binding Java objects to
Jess variables so I can assert them to the engine.
Thanks,
Hunter McMillen
JESS: Is it possible to bind a Java object directly to a Jess variable without creating a new object?
Hi everyone,
I am trying to assert to Jess that an object exists when I encounter a new
object in my Java program. Right now I am using a template to mirror that
object (i.e I have slot values for all of the Java objects fields) but
this seems redundant to me. Is there any way to just bind a Java object to
a Jess variable without creating a new Java object?
A lot of the examples I see online and from JIA are of the form:
(bind ?map (new HashMap))
or
(call Classname method params...)
but these either create a new object or call static methods. I already
have the Java object and just want to store it.
But I was hoping that there was someway I could do something like this:
public Rete engine = new Rete();
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.executeCommand((bind ?unit unit));
engine.executeCommand((assert ?unit));
}
Or would I have to use the store() and fetch() methods for this?
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.store(UNIT, unit);
engine.executeCommand((bind ?unit (fetch UNIT));
engine.executeCommand((assert ?unit));
}
Basically I want to know the best practice for binding Java objects to Jess
variables so I can assert them to the engine.
Thanks,
Hunter McMillen
RE: JESS: Is it possible to bind a Java object directly to a Jess variable without creating a new object?
There are (obviously) two options: (a) put the object somewhere accessible, and
run Jess code that retrieves it, or (b) use Jess's Java API to set a Jess
variable to contain the object. Either would work. The store/fetch mechanism is
sort of an built-in easy way to do (a). Alternatively, say there's a global
variable ?*x* defined in your Jess program. Then you can say
engine.getGlobalContext().setVariable(*x*, new Value(unit));
and your Jess code can later get the value of *x*.
If you don't like using variables this way, there's always directly invoking
Jess functions from Java. Here we invoke 'add' to add the object to working
memory directly:
new Funcall(add, engine).arg(new
Value(unit)).execute(engine.getGlobalContext());
From: owner-jess-us...@sandia.gov [mailto:owner-jess-us...@sandia.gov] On
Behalf Of Hunter McMillen
Sent: Friday, November 04, 2011 1:08 PM
To: jess-users
Subject: JESS: Is it possible to bind a Java object directly to a Jess variable
without creating a new object?
Hi everyone,
I am trying to assert to Jess that an object exists when I encounter a new
object in my Java program. Right now I am using a template to mirror that
object (i.e I have slot values for all of the Java objects fields) but this
seems redundant to me. Is there any way to just bind a Java object to a Jess
variable without creating a new Java object?
A lot of the examples I see online and from JIA are of the form:
(bind ?map (new HashMap))
or
(call Classname method params...)
but these either create a new object or call static methods. I already have
the Java object and just want to store it.
But I was hoping that there was someway I could do something like this:
public Rete engine = new Rete();
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.executeCommand((bind ?unit unit));
engine.executeCommand((assert ?unit));
}
Or would I have to use the store() and fetch() methods for this?
public void unitDiscovered()
{
Unit unit = some unit encountered; //Java object
engine.store(UNIT, unit);
engine.executeCommand((bind ?unit (fetch UNIT));
engine.executeCommand((assert ?unit));
}
Basically I want to know the best practice for binding Java objects to Jess
variables so I can assert them to the engine.
Thanks,
Hunter McMillen
