Re: [rules-users] using complex evaluate expressions with DSL

is there any restriction in terms of using custom function in condition etc. If I add function evaluation to conditions its messing up with dsl. For pattern matching if I use custom function defined in drl then its not able to parse that properly [when][] {attr:\S+} follows pattern {pattern:\S+} = funcToEvalPattern({attr},( {pattern} )

in this case it is getting translated to exists(Person:Person(subordinate != null , funcToEvalPattern( *eval*( name, "I" ) ) ) where as I was hoping this to be exists(Person:Person(subordinate != null , *eval *(funcToEvalPattern( name, "I" ) ) )

Regards, -Maverik On Tue, Jan 4, 2011 at 12:24 PM, maverik j <maverikj348(a)gmail.com&gt; wrote: > cool...this was of great help, I will try this out I think it shoudl solve > the purpose. > > Thanks once again, > Maverik > > 2011/1/3 Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; > > Try using eval as a last resort. A better (smaller, more robust) DSL can >> be designed around facts and their attributes. >> >> "||" (and "OR") can be used, but setting parentheses in order to get the >> priority right is difficult. In constraints, you may have to resort to >> "memberof" or "not memberof". >> >> Your sample isn't self-contained. But I think that the following DSL and >> the DSLR might give you some ideas how to proceed. >> >> [keyword][]check that {conditions}= eval( {conditions} ) >> [keyword][]AND = && >> [keyword][]OR = || >> >> [when][][Tt]here is an? {entity}= {entity}: {entity}() >> [when][][Tt]here is at least one {entity}= exists {entity}: {entity}() >> >> [when][]the {entity:\w+}'s {attr:\w+} = {entity}.get{attr}() >> >> [when][]- with a valid {attr} = {attr}: {attr} != null >> [when][]- with {attr} not equal to {value} = {attr} != {value} >> [when][]- eval\( {whatever} \)=eval( {whatever} ) >> >> [when][] {attr:\S+} follows pattern {pattern:\S+} = {attr}.matches( >> {pattern} ) >> [when][] {attr:\S+} not equals? {value:\S+} = ! {attr}.equals( {value} ) >> [when][] {attr:\S+} is valid = {attr} != null >> >> rule "Rule 5" >> when >> There is a Department >> There is at least one Person >> - with name not equal to "xxx" >> - with a valid subordinate >> - check that the Person's Id is valid AND the Department's Id follows >> pattern "I" AND the Department's HeadOfDpt not equal name >> then >> end >> >> Notice that "-check that..." must be written as a single line. >> >> -W >> >> >> >> >> 2011/1/3 maverik j <maverikj348(a)gmail.com&gt; >> >>> Hi, >>> >>> We are planning to use DSL/DSRL approach with generic DSL template like >>> say >>> >>> [condition][]The {object} has valid {field}={object}({field} != null ) >>> >>> [condition][]there is object {*obj*} that = {*obj*}() >>> >>> [condition][]- has {*attr*} equal {*val*} = {*attr*} == {*val*} >>> >>> [condition][]- has valid {*attr*} = {*attr*} != null >>> >>> [condition][]- and has {*attr*} equal {value}= && {*attr*} == {value} >>> >>> But there are quite few of requirements like to have DSL rules that can >>> generate expression as follows: >>> exists Employee( >>> attribute name not equals "xxx" >>> && the attribute subOrdinate is not null >>> && eval( >>> the attribute $dept.getId() is not null >>> && attribute $dept.getId() follows pattern "I" >>> && ( ! (the attribute $dept.getHeadOfDpt() equals name) >>> ) >>> ) >>> >>> I am not sure if this is possible with DSL. Using '-' operator we cannot >>> really add '&&', '||' conditions it by-default expands to ',' separated and >>> conditions. And wirtting generic rules with and/or is not really dynamic to >>> allow any number of expressions in evaluation. >>> >>> i am struggling to get this run since long time so any help/thoughts on >>> this would be highly appriciable !!! >>> >>> Thanks & Regards, >>> -Maverik >>> >>> _______________________________________________ >>> rules-users mailing list >>> rules-users(a)lists.jboss.org >>> https://lists.jboss.org/mailman/listinfo/rules-users >>> >>> >> >> _______________________________________________ >> rules-users mailing list >> rules-users(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users >> >> > _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users