[gecode-users] Identifying a view

[Christian Schulte]

I think I would turn it upside down: I would use integers as nodes in the
graph and maintain a mapping of these integers to their corresponding views.
Is that possible?

Otherwise, things get hairy: you could hash on the variable implementation
address to which the view is pointing to (if x is a view, then x.varimp()
gives you that). But each time you clone, you would have to rehash as the
varimp() changes.

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 David Rijsman
Sent: Wednesday, February 13, 2013 11:36 AM
To: users at gecode.org
Subject: [gecode-users] Identifying a view

Another question on how we can do this best. Imagine I have a precedence
constraint:

void Gecode::precedence(Home home, IntVar x, IntVar y, int lb, int ub,
IntConLevel=ICL_DEF )

Post temporal propagator that maintains lb <= x - y <= ub 

This will invoke 

Precedence::post( Home home, View x, View y, int lb, int ub )

and this will update the shared handle to some shared distance graph. In the
distance graph we maintain a graph which has vertices for each view. 

What is the best way of mapping a view to a vertex in this graph, that is
how can identify a view to see if it already has been mapped into a vertex
in for example a graph? 

Posting a new precedence constraint has to extend the graph with vertices
for the views if they do not exist yet and add or update the edges between
these vertices. 

any ideas?



David J. Rijsman
Algorithm Lead
Quintiq
 
T +31 (0)73 691 07 39
F +31 (0)73 691 07 54
M +31 (0)62 127 68 29
E david.rijsman at quintiq.com
I www.quintiq.com



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