Re: JESS: How do I assert ordered facts from a map
Ok, that works. Thanks. It didn't make sense to me that I couldn't do this. I remember reading in the book Jess in Action (page 55) where it said eval and build were synonyms and (build ...) was used for constructs and eval for functions out of convention/tradition/historical reasons and not because they did things differently. It is an old book even though I bought it recently. Maybe things have changed since it was written. In addition or maybe in place of data structures like maps, lists, and sets I'd like to load a jdom Document object into the rule engine and have the rules do their thing and read and write to it. That's why I want to be able to create assertions from a data structure and not a bean. It looks like the add, addAll, and getObjects methods just load and retrieve java objects(beans) that are used for shadow facts. Is this true? So I'll be just using store and fetch because this seems to be the only way to get non shadow fact objects in and out of the rule base. The rules won't be doing anything else but reading and writing from and to the stored Document data structure and updating the fact base. No querying or updating databases, reading or writing files, reading and writing from sockets, sending e-mails, or spawning threads, i.e. no side effects. These things will be done outside the rule engine based on the info from the updated Document object. On Aug 14, 2010, at 2:50 AM, Wolfgang Laun wrote: (eval (str-cat (assert ( ?key ((fetch request-parameter-map) get ?key) )) ) ) To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov.
Re: JESS: How do I assert ordered facts from a map
On 15 August 2010 14:09, Donald Winston satchwins...@yahoo.com wrote: Ok, that works. Thanks. It didn't make sense to me that I couldn't do this. I remember reading in the book Jess in Action (page 55) where it said eval and build were synonyms and (build ...) was used for constructs and eval for functions out of convention/tradition/historical reasons and not because they did things differently. It is an old book even though I bought it recently. Maybe things have changed since it was written. Jess did change since that book was written. As with any SW product, go with the doc that comes with it. The reference part is satisfactory. In addition or maybe in place of data structures like maps, lists, and sets I'd like to load a jdom Document object into the rule engine and have the rules do their thing and read and write to it. That's why I want to be able to create assertions from a data structure and not a bean. For XML content into and out of WM, I've frequently used JAXB generated Java classes. I've found this a satisfying, stable approach, with a small footprint due to changes in the data. (Caveat: the XML structure should be reasonable.) It looks like the add, addAll, and getObjects methods just load and retrieve java objects(beans) that are used for shadow facts. Is this true? Yes. So I'll be just using store and fetch because this seems to be the only way to get non shadow fact objects in and out of the rule base. No: it is (assert) and (retract). The functions (fetch) and (store) are for non-WM objects, in a (kind of) global Map provided for the CLIPS interface. The rules won't be doing anything else but reading and writing from and to the stored Document data structure and updating the fact base. No querying or updating databases, reading or writing files, reading and writing from sockets, sending e-mails, or spawning threads, i.e. no side effects. These things will be done outside the rule engine based on the info from the updated Document object. Truth be told, I've never done much work in the marshalling direction, i.e., from WM to a DOM tree. But, here again, I'd investigate the option of building an Object tree (with shadow facts) and use JAXB's marshalling for serializing to XML. -W On Aug 14, 2010, at 2:50 AM, Wolfgang Laun wrote: (eval (str-cat (assert ( ?key ((fetch request-parameter-map) get ?key) )) ) ) To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov.
Re: JESS: How do I assert ordered facts from a map
Try this: (clear) ;; ;; There's no need for an artificial fact to trigger some initial processing. ;; (defrule assert-request-parameters-rule Assert stored data one time. (declare (salience 100)) ;; implied: (eval true) = (foreach ?key (((fetch request-parameter-map) keySet) iterator) ;; produce an assert and eval it (eval (str-cat (assert ( ?key ((fetch request-parameter-map) get ?key) )) ) ) ) ) (defrule got-one (one ?val) = (printout t one has the value ?val crlf) ) (bind ?map (new java.util.HashMap)) (?map put one 1) (?map put two 2) (?map put three 3) (store request-parameter-map ?map) (reset) (run) (facts) On 14 August 2010 04:15, Donald Winston satchwins...@yahoo.com wrote: I just don't want to have to write a lot of Java code to support he use of the rule engine. I realize now I can use the rete.store() to store a Map and put the data in the fact base. I just have to know the keys when I'm coding the rules and use (assert (param-name ?param-value)) I cannot do this: (assert (?param-name ?param-value)) correct? I can also assert unordered facts by using slot names for the keys and use one template for the map instead of creating a lot of little facts vertically. I don't mind changing the rules when the data changes. I do mind having to modify java classes every time some new data is added or deleted. I've used the Blaze Advisor rule engine before. We passed a large hash table of data to it and created the initial fact base for the rules. We passed data back to the app the same way after applying the rules. On Aug 13, 2010, at 2:41 PM, Wolfgang Laun wrote: Donald, Assuming you could assert facts from Map.Entry resulting in simple ordered facts such as (key value) you'd still have to adjust the rules to each change in the key set. This is usually more demanding than adding another deftemplate. In a map all keys are necessarily distinct. This would mean that you create as many different fact types as there are entries. It's difficult to see how you can write rules for this setup (but my bean might be too bean-oriented to see that.) Anyway, you can always (in Java) iterate over the key set, write a simple .clp file containing a deftemplate for each key and slurp this file in (using (batch)) from your main .clp file. Also, you have the option of defining a single fact type (ordered or unordered) for two values, say (deftemplate Entry (slot key) (slot value)) and assert all your Map.Entry things as such. (Rules will have an unusual look-and-feel.) BTW, to execute an (assert ...) from a string you'd have to call (eval). Function (build) is for constructs, i.e., deftemplate, defrule, and cousins. Finally, I have the uncanny feeling that whatever you are trying to solve with this approach might be better solved in a fundamentally different way. But that's just a feeling, like Swing ;-) HTH -W On 13 August 2010 19:27, Donald Winston satchwins...@yahoo.com wrote: ok. Thanks. I won't bother you anymore about this issue. It looks like the proper way to do what I want is to use the Jess java api and create ordered facts from my map using the Fact class and assert them after the rules.clp file has been loaded instead of just storing the map from my java app. (I was looking to minimize the use of the java api when working with the rule engine, but this doesn't look too bad) On Aug 13, 2010, at 11:59 AM, Ernest Friedman-Hill wrote: Java classes are totally optional in Jess -- in fact, templates and facts created directly from the Jess language are always more efficient. If Jess were to store the properties of an object in a Map -- so that they were dynamic and extensible at runtime -- then it would be considerably slower, for the same reason that fully dynamic languages in which objects are maps of code and variables are slower than compiled languages. Construction of a fast Rete network requires knowing what properties are being dealt with. Think of a database in which all the data was stored as object-attribute-value triples -- would it be as fast as a database with fixed tables and columns? On Aug 13, 2010, at 11:41 AM, Donald Winston wrote: So I have to create a template and know all the identifiers before loading data into the fact base? This means I'll have to create java bean objects for all my data. Every time the data changes I'll have to modify the java classes. I don't believe in creating objects for things that have little or no behavior. That's what Maps and Lists are for. I suppose I could generate a init-facts.clp file when my app starts up and load it along with the rules. On Aug 13, 2010, at 11:18 AM, Ernest Friedman-Hill wrote: Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method
Re: JESS: How do I assert ordered facts from a map
Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method toString and call it using the Method object. The compiler needs to know the correct template to use to compile the code, and it can't do that if the name of the template is in a variable. Now, you may ask *could* it work the way you want? Indeed, it could -- but it doesn't at this time. We've talked in the past about allowing this kind of thing, and it has its pros and cons. On Aug 13, 2010, at 11:05 AM, Donald Winston wrote: Can anyone explain to me why this does not work? Why can't I use (deffacts initial-facts Facts to trigger a few appropriate salient initialization rules. (assert-request-parameters)) (defrule assert-request-parameters-rule Assert stored data one time. (declare (salience 100)) ?x - (assert-request-parameters) = (foreach ?key (((fetch request-parameter-map) keySet) iterator) (build str-cat (assert ( ?key ((fetch request- parameter-map) get ?key) ; why not (assert (?key ((fetch request-parameter-map) get ?key (retract ?x)) (bind ?map (new java.util.HashMap)) (?map put one 1) (?map put two 2) (?map put three 3) (store request-parameter-map ?map) (reset) (facts) (run) (facts) Jess, the Rule Engine for the Java Platform Copyright (C) 2008 Sandia Corporation Jess Version 7.1p2 11/5/2008 This copy of Jess will expire in 207 day(s). f-0 (MAIN::initial-fact) f-1 (MAIN::assert-request-parameters) For a total of 2 facts in module MAIN. f-0 (MAIN::initial-fact) For a total of 1 facts in module MAIN. - Ernest Friedman-Hill Informatics Decision Sciences, Sandia National Laboratories PO Box 969, MS 9012, Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov.
Re: JESS: How do I assert ordered facts from a map
So I have to create a template and know all the identifiers before loading data into the fact base? This means I'll have to create java bean objects for all my data. Every time the data changes I'll have to modify the java classes. I don't believe in creating objects for things that have little or no behavior. That's what Maps and Lists are for. I suppose I could generate a init-facts.clp file when my app starts up and load it along with the rules. On Aug 13, 2010, at 11:18 AM, Ernest Friedman-Hill wrote: Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method toString and call it using the Method object. The compiler needs to know the correct template to use to compile the code, and it can't do that if the name of the template is in a variable. Now, you may ask *could* it work the way you want? Indeed, it could -- but it doesn't at this time. We've talked in the past about allowing this kind of thing, and it has its pros and cons. On Aug 13, 2010, at 11:05 AM, Donald Winston wrote: Can anyone explain to me why this does not work? Why can't I use (deffacts initial-facts Facts to trigger a few appropriate salient initialization rules. (assert-request-parameters)) (defrule assert-request-parameters-rule Assert stored data one time. (declare (salience 100)) ?x - (assert-request-parameters) = (foreach ?key (((fetch request-parameter-map) keySet) iterator) (build str-cat (assert ( ?key ((fetch request-parameter-map) get ?key) ; why not (assert (?key ((fetch request-parameter-map) get ?key (retract ?x)) (bind ?map (new java.util.HashMap)) (?map put one 1) (?map put two 2) (?map put three 3) (store request-parameter-map ?map) (reset) (facts) (run) (facts) Jess, the Rule Engine for the Java Platform Copyright (C) 2008 Sandia Corporation Jess Version 7.1p2 11/5/2008 This copy of Jess will expire in 207 day(s). f-0 (MAIN::initial-fact) f-1 (MAIN::assert-request-parameters) For a total of 2 facts in module MAIN. f-0 (MAIN::initial-fact) For a total of 1 facts in module MAIN. - Ernest Friedman-Hill Informatics Decision Sciences, Sandia National Laboratories PO Box 969, MS 9012, Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov. To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov.
Re: JESS: How do I assert ordered facts from a map
Java classes are totally optional in Jess -- in fact, templates and facts created directly from the Jess language are always more efficient. If Jess were to store the properties of an object in a Map -- so that they were dynamic and extensible at runtime -- then it would be considerably slower, for the same reason that fully dynamic languages in which objects are maps of code and variables are slower than compiled languages. Construction of a fast Rete network requires knowing what properties are being dealt with. Think of a database in which all the data was stored as object-attribute-value triples -- would it be as fast as a database with fixed tables and columns? On Aug 13, 2010, at 11:41 AM, Donald Winston wrote: So I have to create a template and know all the identifiers before loading data into the fact base? This means I'll have to create java bean objects for all my data. Every time the data changes I'll have to modify the java classes. I don't believe in creating objects for things that have little or no behavior. That's what Maps and Lists are for. I suppose I could generate a init-facts.clp file when my app starts up and load it along with the rules. On Aug 13, 2010, at 11:18 AM, Ernest Friedman-Hill wrote: Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method toString and call it using the Method object. The compiler needs to know the correct template to use to compile the code, and it can't do that if the name of the template is in a variable. Now, you may ask *could* it work the way you want? Indeed, it could -- but it doesn't at this time. We've talked in the past about allowing this kind of thing, and it has its pros and cons. On Aug 13, 2010, at 11:05 AM, Donald Winston wrote: Can anyone explain to me why this does not work? Why can't I use (deffacts initial-facts Facts to trigger a few appropriate salient initialization rules. (assert-request-parameters)) (defrule assert-request-parameters-rule Assert stored data one time. (declare (salience 100)) ?x - (assert-request-parameters) = (foreach ?key (((fetch request-parameter-map) keySet) iterator) (build str-cat (assert ( ?key ((fetch request- parameter-map) get ?key) ; why not (assert (?key ((fetch request-parameter-map) get ?key (retract ?x)) (bind ?map (new java.util.HashMap)) (?map put one 1) (?map put two 2) (?map put three 3) (store request-parameter-map ?map) (reset) (facts) (run) (facts) Jess, the Rule Engine for the Java Platform Copyright (C) 2008 Sandia Corporation Jess Version 7.1p2 11/5/2008 This copy of Jess will expire in 207 day(s). f-0 (MAIN::initial-fact) f-1 (MAIN::assert-request-parameters) For a total of 2 facts in module MAIN. f-0 (MAIN::initial-fact) For a total of 1 facts in module MAIN. - Ernest Friedman-Hill Informatics Decision Sciences, Sandia National Laboratories PO Box 969, MS 9012, Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com ' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov . To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov . - Ernest Friedman-Hill Informatics Decision Sciences Phone: (925) 294-2154 Sandia National Labs PO Box 969, MS 9012ejfr...@sandia.gov Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov.
Re: JESS: How do I assert ordered facts from a map
As one who's soul is currently languishing in RDF, RDFS, OWL purgatory, let me answer Ernest's rhetorical question: NO000! ;-) On Fri, Aug 13, 2010 at 11:59 AM, Ernest Friedman-Hill ejfr...@sandia.gov wrote: Java classes are totally optional in Jess -- in fact, templates and facts created directly from the Jess language are always more efficient. If Jess were to store the properties of an object in a Map -- so that they were dynamic and extensible at runtime -- then it would be considerably slower, for the same reason that fully dynamic languages in which objects are maps of code and variables are slower than compiled languages. Construction of a fast Rete network requires knowing what properties are being dealt with. Think of a database in which all the data was stored as object-attribute-value triples -- would it be as fast as a database with fixed tables and columns? On Aug 13, 2010, at 11:41 AM, Donald Winston wrote: So I have to create a template and know all the identifiers before loading data into the fact base? This means I'll have to create java bean objects for all my data. Every time the data changes I'll have to modify the java classes. I don't believe in creating objects for things that have little or no behavior. That's what Maps and Lists are for. I suppose I could generate a init-facts.clp file when my app starts up and load it along with the rules. On Aug 13, 2010, at 11:18 AM, Ernest Friedman-Hill wrote: Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method toString and call it using the Method object. The compiler needs to know the correct template to use to compile the code, and it can't do that if the name of the template is in a variable. Now, you may ask *could* it work the way you want? Indeed, it could -- but it doesn't at this time. We've talked in the past about allowing this kind of thing, and it has its pros and cons. On Aug 13, 2010, at 11:05 AM, Donald Winston wrote: Can anyone explain to me why this does not work? Why can't I use (deffacts initial-facts Facts to trigger a few appropriate salient initialization rules. (assert-request-parameters)) (defrule assert-request-parameters-rule Assert stored data one time. (declare (salience 100)) ?x - (assert-request-parameters) = (foreach ?key (((fetch request-parameter-map) keySet) iterator) (build str-cat (assert ( ?key ((fetch request-parameter-map) get ?key) ; why not (assert (?key ((fetch request-parameter-map) get ?key (retract ?x)) (bind ?map (new java.util.HashMap)) (?map put one 1) (?map put two 2) (?map put three 3) (store request-parameter-map ?map) (reset) (facts) (run) (facts) Jess, the Rule Engine for the Java Platform Copyright (C) 2008 Sandia Corporation Jess Version 7.1p2 11/5/2008 This copy of Jess will expire in 207 day(s). f-0 (MAIN::initial-fact) f-1 (MAIN::assert-request-parameters) For a total of 2 facts in module MAIN. f-0 (MAIN::initial-fact) For a total of 1 facts in module MAIN. - Ernest Friedman-Hill Informatics Decision Sciences, Sandia National Laboratories PO Box 969, MS 9012, Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov. To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov. - Ernest Friedman-Hill Informatics Decision Sciences Phone: (925) 294-2154 Sandia National Labs PO Box 969, MS 9012 ejfr...@sandia.gov Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov. -- Cheers, Jason -- Morris Technical Solutions LLC consult...@morris-technical-solutions.com (517) 304-5883
Re: JESS: How do I assert ordered facts from a map
ok. Thanks. I won't bother you anymore about this issue. It looks like the proper way to do what I want is to use the Jess java api and create ordered facts from my map using the Fact class and assert them after the rules.clp file has been loaded instead of just storing the map from my java app. (I was looking to minimize the use of the java api when working with the rule engine, but this doesn't look too bad) On Aug 13, 2010, at 11:59 AM, Ernest Friedman-Hill wrote: Java classes are totally optional in Jess -- in fact, templates and facts created directly from the Jess language are always more efficient. If Jess were to store the properties of an object in a Map -- so that they were dynamic and extensible at runtime -- then it would be considerably slower, for the same reason that fully dynamic languages in which objects are maps of code and variables are slower than compiled languages. Construction of a fast Rete network requires knowing what properties are being dealt with. Think of a database in which all the data was stored as object-attribute-value triples -- would it be as fast as a database with fixed tables and columns? On Aug 13, 2010, at 11:41 AM, Donald Winston wrote: So I have to create a template and know all the identifiers before loading data into the fact base? This means I'll have to create java bean objects for all my data. Every time the data changes I'll have to modify the java classes. I don't believe in creating objects for things that have little or no behavior. That's what Maps and Lists are for. I suppose I could generate a init-facts.clp file when my app starts up and load it along with the rules. On Aug 13, 2010, at 11:18 AM, Ernest Friedman-Hill wrote: Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method toString and call it using the Method object. The compiler needs to know the correct template to use to compile the code, and it can't do that if the name of the template is in a variable. Now, you may ask *could* it work the way you want? Indeed, it could -- but it doesn't at this time. We've talked in the past about allowing this kind of thing, and it has its pros and cons. On Aug 13, 2010, at 11:05 AM, Donald Winston wrote: Can anyone explain to me why this does not work? Why can't I use (deffacts initial-facts Facts to trigger a few appropriate salient initialization rules. (assert-request-parameters)) (defrule assert-request-parameters-rule Assert stored data one time. (declare (salience 100)) ?x - (assert-request-parameters) = (foreach ?key (((fetch request-parameter-map) keySet) iterator) (build str-cat (assert ( ?key ((fetch request-parameter-map) get ?key) ; why not (assert (?key ((fetch request-parameter-map) get ?key (retract ?x)) (bind ?map (new java.util.HashMap)) (?map put one 1) (?map put two 2) (?map put three 3) (store request-parameter-map ?map) (reset) (facts) (run) (facts) Jess, the Rule Engine for the Java Platform Copyright (C) 2008 Sandia Corporation Jess Version 7.1p2 11/5/2008 This copy of Jess will expire in 207 day(s). f-0 (MAIN::initial-fact) f-1 (MAIN::assert-request-parameters) For a total of 2 facts in module MAIN. f-0 (MAIN::initial-fact) For a total of 1 facts in module MAIN. - Ernest Friedman-Hill Informatics Decision Sciences, Sandia National Laboratories PO Box 969, MS 9012, Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov. To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to the list (use your own address!) List problems? Notify owner-jess-us...@sandia.gov. - Ernest Friedman-Hill Informatics Decision Sciences Phone: (925) 294-2154 Sandia National Labs PO Box 969, MS 9012ejfr...@sandia.gov Livermore, CA 94550 http://www.jessrules.com To unsubscribe, send the words 'unsubscribe jess-users y...@address.com' in the BODY of a message to majord...@sandia.gov, NOT to
Re: JESS: How do I assert ordered facts from a map
Donald, Assuming you could assert facts from Map.Entry resulting in simple ordered facts such as (key value) you'd still have to adjust the rules to each change in the key set. This is usually more demanding than adding another deftemplate. In a map all keys are necessarily distinct. This would mean that you create as many different fact types as there are entries. It's difficult to see how you can write rules for this setup (but my bean might be too bean-oriented to see that.) Anyway, you can always (in Java) iterate over the key set, write a simple .clp file containing a deftemplate for each key and slurp this file in (using (batch)) from your main .clp file. Also, you have the option of defining a single fact type (ordered or unordered) for two values, say (deftemplate Entry (slot key) (slot value)) and assert all your Map.Entry things as such. (Rules will have an unusual look-and-feel.) BTW, to execute an (assert ...) from a string you'd have to call (eval). Function (build) is for constructs, i.e., deftemplate, defrule, and cousins. Finally, I have the uncanny feeling that whatever you are trying to solve with this approach might be better solved in a fundamentally different way. But that's just a feeling, like Swing ;-) HTH -W On 13 August 2010 19:27, Donald Winston satchwins...@yahoo.com wrote: ok. Thanks. I won't bother you anymore about this issue. It looks like the proper way to do what I want is to use the Jess java api and create ordered facts from my map using the Fact class and assert them after the rules.clp file has been loaded instead of just storing the map from my java app. (I was looking to minimize the use of the java api when working with the rule engine, but this doesn't look too bad) On Aug 13, 2010, at 11:59 AM, Ernest Friedman-Hill wrote: Java classes are totally optional in Jess -- in fact, templates and facts created directly from the Jess language are always more efficient. If Jess were to store the properties of an object in a Map -- so that they were dynamic and extensible at runtime -- then it would be considerably slower, for the same reason that fully dynamic languages in which objects are maps of code and variables are slower than compiled languages. Construction of a fast Rete network requires knowing what properties are being dealt with. Think of a database in which all the data was stored as object-attribute-value triples -- would it be as fast as a database with fixed tables and columns? On Aug 13, 2010, at 11:41 AM, Donald Winston wrote: So I have to create a template and know all the identifiers before loading data into the fact base? This means I'll have to create java bean objects for all my data. Every time the data changes I'll have to modify the java classes. I don't believe in creating objects for things that have little or no behavior. That's what Maps and Lists are for. I suppose I could generate a init-facts.clp file when my app starts up and load it along with the rules. On Aug 13, 2010, at 11:18 AM, Ernest Friedman-Hill wrote: Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method toString and call it using the Method object. The compiler needs to know the correct template to use to compile the code, and it can't do that if the name of the template is in a variable. Now, you may ask *could* it work the way you want? Indeed, it could -- but it doesn't at this time. We've talked in the past about allowing this kind of thing, and it has its pros and cons. On Aug 13, 2010, at 11:05 AM, Donald Winston wrote: Can anyone explain to me why this does not work? Why can't I use (deffacts initial-facts Facts to trigger a few appropriate salient initialization rules. (assert-request-parameters)) (defrule assert-request-parameters-rule Assert stored data one time. (declare (salience 100)) ?x - (assert-request-parameters) = (foreach ?key (((fetch request-parameter-map) keySet) iterator) (build str-cat (assert ( ?key ((fetch request-parameter-map) get ?key) ; why not (assert (?key ((fetch request-parameter-map) get ?key (retract ?x)) (bind ?map (new java.util.HashMap)) (?map put one 1) (?map put two 2) (?map put three 3) (store request-parameter-map ?map) (reset) (facts) (run) (facts) Jess, the Rule Engine for the Java Platform Copyright (C) 2008 Sandia Corporation Jess Version 7.1p2 11/5/2008 This copy of Jess will expire in 207 day(s). f-0 (MAIN::initial-fact) f-1 (MAIN::assert-request-parameters) For a total of 2 facts in module MAIN. f-0 (MAIN::initial-fact) For a total of 1 facts in module MAIN. - Ernest Friedman-Hill Informatics Decision
Re: JESS: How do I assert ordered facts from a map
I just don't want to have to write a lot of Java code to support he use of the rule engine. I realize now I can use the rete.store() to store a Map and put the data in the fact base. I just have to know the keys when I'm coding the rules and use (assert (param-name ?param-value)) I cannot do this: (assert (?param-name ?param-value)) correct? I can also assert unordered facts by using slot names for the keys and use one template for the map instead of creating a lot of little facts vertically. I don't mind changing the rules when the data changes. I do mind having to modify java classes every time some new data is added or deleted. I've used the Blaze Advisor rule engine before. We passed a large hash table of data to it and created the initial fact base for the rules. We passed data back to the app the same way after applying the rules. On Aug 13, 2010, at 2:41 PM, Wolfgang Laun wrote: Donald, Assuming you could assert facts from Map.Entry resulting in simple ordered facts such as (key value) you'd still have to adjust the rules to each change in the key set. This is usually more demanding than adding another deftemplate. In a map all keys are necessarily distinct. This would mean that you create as many different fact types as there are entries. It's difficult to see how you can write rules for this setup (but my bean might be too bean-oriented to see that.) Anyway, you can always (in Java) iterate over the key set, write a simple .clp file containing a deftemplate for each key and slurp this file in (using (batch)) from your main .clp file. Also, you have the option of defining a single fact type (ordered or unordered) for two values, say (deftemplate Entry (slot key) (slot value)) and assert all your Map.Entry things as such. (Rules will have an unusual look-and-feel.) BTW, to execute an (assert ...) from a string you'd have to call (eval). Function (build) is for constructs, i.e., deftemplate, defrule, and cousins. Finally, I have the uncanny feeling that whatever you are trying to solve with this approach might be better solved in a fundamentally different way. But that's just a feeling, like Swing ;-) HTH -W On 13 August 2010 19:27, Donald Winston satchwins...@yahoo.com wrote: ok. Thanks. I won't bother you anymore about this issue. It looks like the proper way to do what I want is to use the Jess java api and create ordered facts from my map using the Fact class and assert them after the rules.clp file has been loaded instead of just storing the map from my java app. (I was looking to minimize the use of the java api when working with the rule engine, but this doesn't look too bad) On Aug 13, 2010, at 11:59 AM, Ernest Friedman-Hill wrote: Java classes are totally optional in Jess -- in fact, templates and facts created directly from the Jess language are always more efficient. If Jess were to store the properties of an object in a Map -- so that they were dynamic and extensible at runtime -- then it would be considerably slower, for the same reason that fully dynamic languages in which objects are maps of code and variables are slower than compiled languages. Construction of a fast Rete network requires knowing what properties are being dealt with. Think of a database in which all the data was stored as object-attribute-value triples -- would it be as fast as a database with fixed tables and columns? On Aug 13, 2010, at 11:41 AM, Donald Winston wrote: So I have to create a template and know all the identifiers before loading data into the fact base? This means I'll have to create java bean objects for all my data. Every time the data changes I'll have to modify the java classes. I don't believe in creating objects for things that have little or no behavior. That's what Maps and Lists are for. I suppose I could generate a init-facts.clp file when my app starts up and load it along with the rules. On Aug 13, 2010, at 11:18 AM, Ernest Friedman-Hill wrote: Basically for the same reason that you can't say something like this in Java: String theMethodName = toString; String myString = myObject.(theMethodName)(); but instead you have to use reflection to find the method toString and call it using the Method object. The compiler needs to know the correct template to use to compile the code, and it can't do that if the name of the template is in a variable. Now, you may ask *could* it work the way you want? Indeed, it could -- but it doesn't at this time. We've talked in the past about allowing this kind of thing, and it has its pros and cons. On Aug 13, 2010, at 11:05 AM, Donald Winston wrote: Can anyone explain to me why this does not work? Why can't I use (deffacts initial-facts Facts to trigger a few appropriate salient initialization rules. (assert-request-parameters)) (defrule
