After a couple hours on the mail archive, I found the problem. When I added
the defglobal to the Rete engine I used this command:
*Defglobal playerIDGlobal = new Defglobal("*PLAYER_ID*", new
Value(self.getID()));*
*engine.addDefglobal(playerIDGlobal);*
*
*
But this doesn't specify a type for the Value object, so when I tried to
match against *?*PLAYER_ID** on the lhs of my rules it always returned
false because the type of the defglobal was defaulted to Java object. I
changed the command to this:
*Defglobal playerIDGlobal = new Defglobal("*PLAYER_ID*", new
Value(self.getID(), RU.INTEGER));*
*engine.addDefglobal(playerIDGlobal);*
*
*
And now everything seems to be working fine, Just out of curiosity though
how does Jess infer types of variables when it is matching on the lhs of
rules?
Thanks,
Hunter McMillen
On Wed, Jan 11, 2012 at 6:04 PM, Friedman-Hill, Ernest
<ejfr...@sandia.gov>wrote:
> For everything to work right, you always have to use the asterisks (as I
> said, they're part of the name), and you must include a (defglobal)
> declaration before using the variable. Setting a global variable "by hand"
> without declaring it first produces undefined results (I.e., it'll work
> right some of the time.)
>
> From: Hunter McMillen <mcmil...@gmail.com>
> Reply-To: <jess-users@sandia.gov>
> Date: Wed, 11 Jan 2012 16:37:11 -0500
> To: <jess-users@sandia.gov>
> Subject: Re: JESS: [EXTERNAL] How to negate a variable when in lhs of a
> rule
>
> I placed the asterisks around PLAYER_ID then still received an error
> when the rule fired: " No such variable *PLAYER_ID*" But then noticed that
> when I call setVariable, I name the variable PLAYER_ID not *PLAYER_ID* so I
> changed my statement to this:
>
> *engine.getGlobalContext().setVariable("*PLAYER_ID*", new
> Value(player.getID());*
>
> and everything works fine.
>
> Does* getGlobalContext().setVariable(...)* define global variables
> implicitly? or do you have to include the asterisks like I did?
>
> Thanks.
> Hunter McMillen
>
> On Wed, Jan 11, 2012 at 3:13 PM, Friedman-Hill, Ernest <ejfr...@sandia.gov
> > wrote:
>
>> The asterisks are part of the defglobal's name. You're not comparing to
>> the defglobal: you're binding the value in the slot to a new variable. It's
>> not legal to negate such a constraint in its first use, as the error
>> message said. You need to use
>>
>> * (unit (ID ?id) (typeID ?typeID) (player ~?*PLAYER_ID*))*
>>
>>
>> From: Hunter McMillen <mcmil...@gmail.com>
>> Reply-To: <jess-users@sandia.gov>
>> Date: Wed, 11 Jan 2012 14:38:31 -0500
>> To: <jess-users@sandia.gov>
>> Subject: JESS: [EXTERNAL] How to negate a variable when in lhs of a rule
>>
>> Hi everyone,
>>
>> I am trying to differentiate between Objects that belong to a certain
>> user inside two of my rules.
>>
>> I have a variable created from Java like this:
>>
>> *engine.getGlobalContext().setVariable("PLAYER_ID", new
>> Value(player.getID());*
>> *
>> *
>> And I want to use this variable in rules to determine which objects
>> belong to each player.
>>
>> This rule works fine when just using ?PLAYER_ID
>> *(defrule myUnitSeen *
>> * (unit (ID ?id) (typeID ?typeID) (player ?PLAYER_ID))*
>> *=>*
>> * .....)*
>> *
>> *
>> But when I try to negate the variable I get an error, "First use of
>> variable negated: PLAYER_ID"
>> *(defrule enemyUnitSeen *
>> * (unit (ID ?id) (typeID ?typeID) (player ~?PLAYER_ID))*
>> *=>*
>> * .....)*
>> *
>> *
>> How can I specify anything other than ?PLAYER_ID on the lhs of a rule?
>>
>> Thanks,
>> Hunter McMillen
>>
>
>
