There is no xor-group for 3.0. will be in 3.1

Mark
Ho, Alan wrote:
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]









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