[gecode-users] Remapping of BoolVar propagation conditions

[Christian Schulte]

Yep, that's right. Sorry, I forgot that the rewriting is done in the
implementation and not in the views!

Christian

-----Original Message-----
From: Guido Tack [mailto:tack at ps.uni-sb.de] 
Sent: Tuesday, December 01, 2009 4:31 PM
To: Vincent Barichard
Cc: Christian Schulte; 'gecode list'
Subject: Re: [gecode-users] Remapping of BoolVar propagation conditions

Hi Vincent,

the rewriting is currently done in int/var-imp/bool.hpp.  Just remove the
rewriting there and pass the pc unchanged, add rewriting to all the normal
Gecode BoolView classes, and then add your own BoolView class that doesn't
rewrite.

Cheers,
	Guido

Vincent Barichard wrote:

> Dear Christian,
> 
> Thank you very much for your mail. I'm sorry, I don't understand your
answer. Why having other BoolView classes will
> help me ? I added member functions in the BoolViews classes. I didn't
change the existing ones,
> I only added member functions which notify the ME_BOOL_SAME event.
> 
> In my own propagator (let's call it M) I call the recently added functions
in the BoolViews. So the ME_BOOL_SAME
> event is sent.
> 
> I also modified one propagator of Gecode (let's call it P') and make it
subscribe to the PC_BOOL_SAME propagation condition (I only added
"x1.subscribe(home, *this, PC_BOOL_SAME)" in constructor).
> In the "propagate" function of P' I added instructions which are only
relevant if a ME_BOOL_SAME event has been sent before.
> 
> So when M is woke up (because it subscribe to PC_BOOL_VAL propagation
condition) it may call the new member functions in the BoolViews classes
which sent the ME_BOOL_SAME event. I would like that propagators which
subscribe to the PC_BOOL_SAME propagation condition and only these ones, be
scheduled to wake up (for example P' will be scheduled if it shares a
variable with M). As no assignment has been made by the M propagator, I
don't want that other propagators wake up except if a ME_BOOL_VAL event has
been sent from elsewhere.
> 
> Unfortunately, as all propagation condition subscribings for Boleans
variables are remapped to PC_BOOL_VAL, P' will not awake if a ME_BOOL_SAME
event is sent.
> 
> May have I another choice but to use the ME_BOOL_VAL event instead of
ME_BOOL_SAME in my new member functions of the BoolView classes ? As a
result, all propagators will be awaken even if they can't propagate removal,
indeed no assignment has been made.

> 
> Don't hesitate to ask me if I'm not clear enough.
> 
> Cheers,
> Vincent
> 
> Le 30 nov. 09 à 16:35, Christian Schulte a écrit :
> 
>> Actually what you have to do is the following: you define two classes for
>> Boolean views, one that rewrites its propagation conditions and the other
>> one that does not. Then your propagators can use the views without
rewriting
>> while the other propagators can use the variables with rewriting.
>> 
>> Christian
>> 
>> --
>> Christian Schulte, www.ict.kth.se/~cschulte/
>> 
>> 
>> -----Original Message-----
>> From: users-bounces at gecode.org [mailto:users-bounces at gecode.org] On
Behalf
>> Of Vincent Barichard
>> Sent: Monday, November 30, 2009 9:33 AM
>> To: Christian Schulte
>> Cc: 'Guido Tack'; 'gecode list'
>> Subject: Re: [gecode-users] Remapping of BoolVar propagation conditions
>> 
>> Hi,
>> 
>> Thank you both for your answers. As I don't want to break all propagators
>> that are used for integer as well as boolean variables, I see no choice
but
>> to use PC_BOOL_VAL.
>> 
>> Maybe one of you may see another way ? I make new functions on Boolean
>> variables (and associated views) which don't set domain to 1 or 0 (I
copied
>> "ModEvent  BoolVarImp::one_none(Space& home)" and removed the unwanted
>> instructions). These functions notify new events (called ME_BOOL_SAME in
>> bool.vis file (see attached file)). I mapped this new event to the
>> PC_BOOL_SAME propagation condition.
>> 
>> Now I change an existing propagator (like the "Or" propagator), and I
want
>> it to be awaken when ME_BOOL_SAME is emitted. As the variable is not yet
>> assigned, I didn't want to emit the ME_BOOL_VAL event because I didn't
want
>> to wake up propagators which only subscribed to the PC_BOOL_VAL
condition.
>> 
>> So during propagation, I call my new functions on Boolean variables, the
>> ME_BOOL_SAME event is sent and propagators which subscribe to the
>> PC_BOOL_SAME condition are wake up. Other propagators are not awaken
(except
>> if a ME_BOOL_VAL event has also been sent). Is it possible ?
>> Should I use ME_BOOL_VAL ? If I use ME_BOOL_VAL other propagators will be
>> awaken for nothing.
>> 
>> Thanks for your help.
>> 
>> Cheers,
>> Vincent
> 
> Vincent Barichard         Université d'Angers (LERIA)
> Tel: 02 41 73 52 06      Département Informatique
> Fax: 02 41 73 50 73     H203
>