set_enum_constraints.rb in gecoder-0.9.0

- old
+ new
@@ -1,34 +1,84 @@
-module Gecode
-  module SetEnumMethods
-    include Gecode::Constraints::LeftHandSideMethods
-    
+# A module containing constraints that have enumerations of set operands as 
+# left hand side.
+module Gecode::SetEnum #:nodoc:
+  # A SetEnumOperand is a enumeration of SetOperand on which the
+  # constraints defined in SetEnumConstraintReceiver can be placed.
+  #
+  # Enumerations of set operands can be created either by using
+  # Gecode::Model#set_var_array and Gecode::Model#set_var_matrix, or
+  # by wrapping an existing enumeration containing SetOperand using
+  # Gecode::Model#wrap_enum. The enumerations, no matter how they were
+  # created, all respond to the properties defined by SetEnumOperand.
+  #
+  # ==== Examples 
+  #
+  # Produces an array of five set operands, with greatest lower bound
+  # {0} and least upper bound {0, 1, 2}, inside a problem formulation
+  # using Gecode::Model#set_var_array:
+  #
+  #   set_enum = set_var_array(5, 0, 1..2)
+  #
+  # Uses Gecode::Model#wrap_enum inside a problem formulation to create
+  # a SetEnumOperand from an existing enumeration containing the
+  # set operands +set_operand1+ and +set_operand2+:
+  #
+  #   set_enum = wrap_enum([set_operand1, set_operand2])
+  #   
+  #--
+  # Classes that mix in SetEnumOperand must define #model and
+  # #to_set_enum .
+  module SetEnumOperand
+    include Gecode::Operand 
+
+    def method_missing(method, *args) #:nodoc:
+      if Gecode::SetEnum::Dummy.instance_methods.include? method.to_s
+        # Delegate to the set enum.
+        to_set_enum.method(method).call(*args)
+      else
+        super
+      end
+    end
+
     private
-    
-    # Produces an expression for the lhs module.
-    def expression(params)
-      params.update(:lhs => self)
-      Constraints::SetEnum::Expression.new(@model, params)
+
+    def construct_receiver(params)
+      Gecode::SetEnum::SetEnumConstraintReceiver.new(@model, params)
     end
   end
-  
-  # A module containing constraints that have enumerations of set variables as 
-  # left hand side.
-  module Constraints::SetEnum
-    # Expressions with set enums as left hand sides.
-    class Expression < Gecode::Constraints::Expression
-      # Raises TypeError unless the left hand side is a set enum.
-      def initialize(model, params)
-        super
-        
-        unless params[:lhs].respond_to? :to_set_var_array
-          raise TypeError, 'Must have set enum as left hand side.'
-        end
+
+  # SetEnumConstraintReceiver contains all constraints that can be
+  # placed on a SetEnumOperand.
+  #
+  # Constraints are placed by calling SetEnumOperand#must (or any other
+  # of the variations defined in Operand), which produces a 
+  # SetEnumConstraintReceiver from which the desired constraint can be used.
+  #
+  # ==== Examples 
+  #
+  # Constrains +set_enum+ to channel +int_enum+ by using 
+  # SetEnumConstraintReceiver#channel:
+  #
+  #   set_enum.must.channel set_enum
+  #
+  # Constrains each pair of set operands in +set_enum+ to at most share
+  # one element. Also constrains each set to have size 17. Uses 
+  # SetEnumConstraintReceiver#at_most_share_one_element.
+  #
+  #   set_enum.must.at_most_share_one_element(:size => 17)
+  #
+  class SetEnumConstraintReceiver < Gecode::ConstraintReceiver
+    # Raises TypeError unless the left hand side is a set enum operand.
+    def initialize(model, params) #:nodoc:
+      super
+      
+      unless params[:lhs].respond_to? :to_set_enum
+        raise TypeError, 'Must have set enum operand as left hand side.'
       end
     end
   end
 end
 
 require 'gecoder/interface/constraints/set_enum/channel'
 require 'gecoder/interface/constraints/set_enum/distinct'
-require 'gecoder/interface/constraints/set_enum/selection'
+require 'gecoder/interface/constraints/set_enum/select'
 require 'gecoder/interface/constraints/set_enum/operation'