Gecoder C0 Coverage Information - RCov

     # Constrains this enumeration to "channel" +int_enum+.  Channel

     # constraints are used to give access to multiple viewpoints when

     # modelling. 

     # 

     # The channel constraint can be thought of as constraining the arrays to 

     # be each other's inverses. I.e. if the i:th value in the first enumeration

     # is j, then the j:th value in the second enumeration is constrained to be 

     # i.

     # 

     # Neither reification nor negation is supported.

     # 

     # ==== Examples 

     # 

     # Lets say that we're modelling a sequence of numbers that must be distinct

     # and that we want access to the following two view simultaneously.

     # 

     # === First view

     # 

     # The sequence is modelled as an array of integer variables where the first 

     # variable holds the value of the first position in the sequence, the 

     # second the value of the second position and so on.

     # 

     #   # n variables with values from 0 to n-1.

     #   elements = int_var_array(n, 0...n)

     #   elements.must_be.distinct

     # 

     # That way +elements+ will contain the actual sequence when the problem has 

     # been solved.

     # 

     # === Second view

     # 

     # The sequence is modelled as the positions of each value in 0..(n-1) in 

     # the sequence. That way the first variable would hold the positions of 0 

     # in the sequence, the second variable would hold the positions of 1 in the 

     # sequence and so on.

     # 

     #   positions = int_var_array(n, 0...n)

     #   positions.must_be.distinct

     # 

     # === Connecting the views

     #   

     # In essence the relationship between the two arrays +elements+ and 

     # +positions+ is that

     # 

     #   elements.map{ |e| e.val }[i] == positions.map{ |p| p.val }.index(i)

     # 

     # for all i in 0..(n-1). This relationship is enforced by the channel 

     # constraint as follows. 

     # 

     #   elements.must.channel positions

     # 

           'is not implemented.'

       end

       end

           'reification option.'

       end

     end

     # Provides commutativity with SetEnumConstraintReceiver#channel .

   end

   # A module that gathers the classes and modules used in channel constraints.

       end

     end

   end

 end