lib/piglet/relation/stream.rb in piglet-0.2.3 vs lib/piglet/relation/stream.rb in piglet-0.2.4

@@ -1,7 +1,41 @@
 module Piglet
   module Relation
     class Stream # :nodoc:
       include Relation
+      
+      def initialize(source, args, options=nil)
+        options ||= {}
+        @sources = [source]
+        args.each do |arg|
+          @sources << arg if arg.is_a?(Relation) || arg.is_a?(Array)
+        end
+        @command_reference = (args - @sources).first
+        @sources = @sources.flatten
+        @command = options[:command]
+        @schema = options[:schema]
+      end
+      
+      def schema
+        if @schema
+          Piglet::Schema::Tuple.parse(@schema)
+        else
+          nil
+        end
+      end
+      
+      def to_s
+        source_str = @sources.map { |s| s.alias }.join(', ')
+        str = "STREAM #{source_str} THROUGH"
+        if @command_reference
+          str << " #{@command_reference}" 
+        else
+          str << " `#{@command}`"
+        end
+        if @schema
+          str << " AS #{schema}"
+        end
+        str
+      end
     end
   end
 end
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