lib/piglet/field/udf_expression.rb in piglet-0.2.5 vs lib/piglet/field/udf_expression.rb in piglet-0.3.0

@@ -3,14 +3,19 @@
     class UdfExpression
       include Field
       
       def initialize(ali4s, *args)
         @alias, @args = ali4s, args
+        @predecessors = args.select { |arg| arg.respond_to? :field_alias }
       end
       
-      def to_s
-        "#{@alias}(#{args_to_s(@args)})"
+      def to_s(inner=false)
+        if inner
+          "#{@alias}(#{args_to_inner_s(@args)})"
+        else
+          "#{@alias}(#{args_to_s(@args)})"
+        end
       end
       
     private
       
       def args_to_s(arg)
@@ -19,9 +24,21 @@
           "'#{escape(arg)}'"
         when Enumerable
           arg.map { |a| args_to_s(a) }.join(', ')
         else
           arg
+        end
+      end
+      
+      def args_to_inner_s(arg)
+        if arg.is_a? String
+          "'#{escape(arg)}'"
+        elsif arg.is_a? Enumerable
+          arg.map { |a| args_to_inner_s(a) }.join(", ")
+        elsif arg.respond_to? :field_alias
+          arg.field_alias
+        else
+          arg.to_s
         end
       end
     end
   end
 end
\ No newline at end of file