I vote no on having 'else'. The switch statement is exactly the same as the "xorGroup" concept in DROOLS (aka mutually exclusive rules). In DROOLs 3, how do you make a set of rules to be part of an XOR group ?
Regards, Alan Ho -----Original Message----- From: Dmitry Goldenberg [mailto:[EMAIL PROTECTED] Sent: Tuesday, April 11, 2006 7:57 AM To: [email protected] Subject: RE: [drools-user] How to express conditional logic via DRL - ? This is actually the reasong I went through- wanting to use Drools as a script execution framework. Ideally, I'd like to see support for IF-THEN-ELSE and possibly SWITCH. As of now, I don't see a need for any other "procedural" constructs but it seems to me that IF-THEN-ELSE would be an immediate need for our users. It would be nice to have explicit support for it, rather than a whole chapter in our doc explaining how to achieve it with multiple rules in a rule-set. Thanks, - Dmitry ________________________________ From: Mark Proctor [mailto:[EMAIL PROTECTED] Sent: Tue 4/11/2006 10:46 AM To: [email protected] Subject: Re: [drools-user] How to express conditional logic via DRL - ? Unfortunately I'm finding that many people just cannot adjust to the declarative and coupletely decoupled nature of a rule engine. The end result is that Drools is used as a script execution framework. Felipe Piccolini wrote: > Mark, > > I could vote on this, I would vote no to the 'else'. The declarative > thing about rule engines is that: no procedural code. So if you > wanna do an 'else' condition you should re-think your rule and chack > if its well writen. Of course this is just MHO. > > :) > > Tuesday, April 11, 2006, 6:09:22 AM, you wrote: > > >> I thought about adding 'else' but I couldn't decide on the best way >> to implement it, as there are several possabilities. Also 'else' is >> not considered declarative, so its a kinda of code smell. I'll llook >> into this again in 3.1 >> > > >> Mark >> Geoffrey Wiseman wrote: >> >>> On 4/10/06, Dmitry Goldenberg <[EMAIL PROTECTED]> wrote: >>> >>> >>>> What is the timeframe for 3.1? Else/else if are very important to >>>> what we're trying to do. >>>> >>>> I can see how I can to the following with the method described by >>>> Geoffrey: >>>> >>>> if (A) then B else if (C) then D endif >>>> >>>> I also want to be able to do the following: >>>> >>>> if (A) then B else D endif >>>> >>>> I imagine that the rule would have to be written as a combo of >>>> >>>> if (A) then B endif >>>> if (!A) then D endif >>>> >>>> so that the conditions are complimentary... >>>> >>>> >>>> >>> Indeed, yes, that's how you'd handle it. >>> >>> If it does make it into 3.1, that's a good thing in terms of >>> supporting the way people think, talk, and work in other languages, >>> but fundamentally, the same capabilities are there now -- they just require >>> more typing. >>> >>> - Geoffrey >>> -- >>> Geoffrey Wiseman >>> >>> >>> > > > > -------------------------- > Felipe Piccolini > [EMAIL PROTECTED] > > > >
