equation.rb in danica-2.6.0

- old
+ new

@@ -1,17 +1,28 @@
 module Danica
   class Equation
     include Common
     include VariablesHolder
+  
+    autoload :Builder, 'danica/equation/builder'
 
-    variables :left, :right
-
     def initialize(*args)
       self.variables = args.flatten
     end
 
+    class << self
+      def build(*variables, &block)
+        Builder.new(*variables, &block).build
+      end
+
+      def create(*variables, &block)
+        build(*variables, &block).new
+      end
+    end
+
     def to(format)
       "#{left.to(format)} = #{right.to(format)}"
     end
   end
 end
+
 