RE: JESS: [EXTERNAL] bsave fails after defquery execution [was: Dynamic rule-base analysis]

It would certainly make sense for this class to be Serializable, as most =
other classes in Jess are. The current implementation in practice contain=
s an instance of java.util.ArrayList.Itr, which is not Seriaizable, so a =
certain amount of coding would be involved in making this change. Worth d=
oing, though, so I'll see if we can work it in.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On=
 Behalf Of Jonathan Sewall
Sent: Monday, September 30, 2013 9:49 AM
To: jess-users
Subject: JESS: [EXTERNAL] bsave fails after defquery execution [was: Dyna=
mic rule-base analysis]

[Apologies for the incorrect Subject: on this report yesterday, 9/29.]

The trouble with bsave after executing a defquery appears to happen when =
serializing the Map Context.m_variables in Rete.m_globalContext: at this =
point in the script, the map holds the QueryResult variable ?qr:

     (bind ?qr (run-query* all-cars))

Hence, if I execute

     (bind ?qr "not a QueryResult")

before the 2nd bsave, then the script runs without error. Could QueryResu=
lt be made Serializable? Revised script and results below.=20
Thanks again,

			Jonathan Sewall

------- Original Message --------
Subject: 	Re: JESS: [EXTERNAL] Dynamic rule-base analysis
Date: 	Sun, 29 Sep 2013 18:04:11 -0400
From: 	Jonathan Sewall <[email protected]>
Reply-To: 	[email protected], [email protected]
To: 	[email protected]

...

Contents of script.clp:

(deftemplate car (slot make) (slot model)) (defquery all-cars "Get all ca=
rs." ?car <- (car)) (defquery cars-of-make "Get cars of the given make." =
(declare (variables
?want-make)) ?car <- (car (make ?m&:(=3D ?m ?want-make))))
(reset)
(bind ?pickup (assert (car (make "Ford") (model "F100")))) (bind ?sedan (=
assert (car (make "Honda") (model "Civic")))) (bind ?suv (assert (car (ma=
ke "Ford") (model "Explorer")))) (printout t "*** Before 1st bsave ***" c=
rlf) (printout t "globalContext " (((engine) getGlobalContext) toString) =
crlf) (bsave "s1.bsave") (bind ?qr (run-query* all-cars)) (while (?qr nex=
t) (bind ?car (?qr getObject "car")) (printout t (?car
toString) crlf))
(?qr close)
(printout t "*** Before 2nd bsave ***" crlf) (printout t "globalContext "=
 (((engine) getGlobalContext) toString) crlf) ;; (bind ?qr "not a QueryRe=
sult") ;; uncomment to make script run ok (bsave "s2.bsave")

Results:

$ java -cp lib/jess.jar jess.Main

Jess, the Rule Engine for the Java Platform Copyright (C) 2008 Sandia Cor=
poration Jess Version 7.1p2 11/5/2008

Jess> (batch "script.clp")
*** Before 1st bsave ***
globalContext [Context, 3 variables:=20
pickup=3D<Fact-1>;sedan=3D<Fact-2>;suv=3D<Fact-3>;]
(MAIN::car (make "Ford") (model "F100")) (MAIN::car (make "Honda") (model=
 "Civic")) (MAIN::car (make "Ford") (model "Explorer"))
*** Before 2nd bsave ***
globalContext [Context, 5 variables:=20
car=3D<Java-Object:jess.Fact>;pickup=3D<Fact-1>;sedan=3D<Fact-2>;suv=3D<F=
act-3>;qr=3D<Java-Object:jess.QueryResult>;]
Jess reported an error in routine bsave
	while executing (bsave "s2.bsave")
	while executing (batch "script.clp").
   Message: IO Exception.
   Program text: ( bsave "s2.bsave" )  at line 17 in file script.clp.

Nested exception is:
jess.QueryResult
Jess>
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