distinct.rb in gecoder-0.9.0

- old
+ new

@@ -1,25 +1,28 @@
-module Gecode
-  module IntEnumMethods
-    # Specifies offsets to be used with a distinct constraint. The offsets can
-    # be specified one by one or as an array of offsets.
-    def with_offsets(*offsets)
-      if offsets.kind_of? Enumerable
-        offsets = *offsets
-      end
-      params = {:lhs => self, :offsets => offsets}
-      
-      Gecode::Constraints::SimpleExpressionStub.new(@model, params) do |m, ps|
-        Gecode::Constraints::IntEnum::Expression.new(m, ps)
-      end
-    end
-  end
-end
-
-module Gecode::Constraints::IntEnum
-  class Expression
-    # Posts a distinct constraint on the variables in the enum.
+module Gecode::IntEnum
+  class IntEnumConstraintReceiver
+    # Constrains all integer operands in the enumeration to be distinct
+    # (different). The constraint can also be used with constant
+    # offsets, so that the operands, with specified offsets added, must
+    # be distinct.
+    # 
+    # The constraint does not support negation nor reification.
+    # 
+    # ==== Examples 
+    # 
+    #   # Constrains all operands in +int_enum+ to be assigned different 
+    #   # values.
+    #   int_enum.must_be.distinct
+    #   
+    #   # The same as above, but also selects that the strength +domain+ should
+    #   # be used.
+    #   int_enum.must_be.distinct(:strength => :domain)
+    #   
+    #   # Uses the offset to constrain that no number may be the previous number
+    #   # incremented by one.
+    #   numbers = int_var_array(8, 0..9)
+    #   numbers.must_be.distinct(:offsets => (1..numbers.size).to_a.reverse)
     def distinct(options = {})
       if @params[:negate]
         # The best we could implement it as from here would be a bunch of 
         # reified pairwise equality constraints. 
         raise Gecode::MissingConstraintError, 'A negated distinct is not ' + 
@@ -27,48 +30,35 @@
       end
       unless options[:reify].nil?
         raise ArgumentError, 'Reification is not supported by the distinct ' + 
           'constraint.'
       end
-      
+
+      if options.has_key? :offsets
+        offsets = options.delete(:offsets)
+        unless offsets.kind_of? Enumerable
+          raise TypeError, 'Expected Enumerable as offsets, got ' + 
+            "#{offsets.class}."
+        end
+        @params[:offsets] = offsets
+      end
       @model.add_constraint Distinct::DistinctConstraint.new(@model, 
-        @params.update(Gecode::Constraints::Util.decode_options(options)))
+        @params.update(Gecode::Util.decode_options(options)))
     end
   end
   
   # A module that gathers the classes and modules used in distinct constraints.
   module Distinct #:nodoc:
-    # Describes a distinct constraint, which constrains all integer variables 
-    # in an enumeration to be distinct (different). The constraint can also be
-    # used with constant offsets, so that the variables, with specified offsets
-    # added, must be distinct.
-    # 
-    # The constraint does not support negation nor reification.
-    # 
-    # == Examples
-    # 
-    #   # Constrains all variables in +int_enum+ to be assigned different 
-    #   # values.
-    #   int_enum.must_be.distinct
-    #   
-    #   # The same as above, but also selects that the strength +domain+ should
-    #   # be used.
-    #   int_enum.must_be.distinct(:strength => :domain)
-    #   
-    #   # Uses the offset to constrain that no number may be the previous number
-    #   # incremented by one.
-    #   numbers = int_var_array(8, 0..9)
-    #   numbers.with_offset((1..numbers.size).to_a.reverse).must_be.distinct
-    class DistinctConstraint < Gecode::Constraints::Constraint
+    class DistinctConstraint < Gecode::Constraint #:nodoc:
       def post
         # Bind lhs.
-        @params[:lhs] = @params[:lhs].to_int_var_array
+        @params[:lhs] = @params[:lhs].to_int_enum.bind_array
         
         # Fetch the parameters to Gecode.
         params = @params.values_at(:offsets, :lhs)
         params.delete_if{ |x| x.nil? }
         params.concat propagation_options
         Gecode::Raw::distinct(@model.active_space, *params)
       end
     end
   end
-end
\ No newline at end of file
+end