diff --git a/lib/eddy/build/loop/base.rb b/lib/eddy/build/loop/base.rb
index 44eb24b..5dc7981 100644
--- a/lib/eddy/build/loop/base.rb
+++ b/lib/eddy/build/loop/base.rb
@@ -44,9 +44,7 @@ def initialize(store)
                 super(store, Repeat)
               end
 
-              # Add a repeat of loop #{self.summary.id}.
-              #
-              # @yieldparam [Eddy::TransactionSets::#{self.t_set_id}::Loops::#{self.summary.id}::Repeat] rep
+              # @yieldparam [Eddy::TransactionSets::#{self.t_set_id}::Loops::#{self.summary.id}::Repeat]
               # @return [void]
               def repeat(&block)
                 super(&block)
diff --git a/lib/eddy/build/transaction_set_builder.rb b/lib/eddy/build/transaction_set_builder.rb
index c8bafb2..a8ee024 100644
--- a/lib/eddy/build/transaction_set_builder.rb
+++ b/lib/eddy/build/transaction_set_builder.rb
@@ -9,17 +9,13 @@ class TransactionSetBuilder
 
       # @return [Eddy::Summary::TransactionSet]
       attr_accessor :summary
-      # @return [String] (nil)
-      attr_accessor :folder
-      # @return [Boolean] (false)
-      attr_accessor :headers
 
+      # @param summary [Eddy::Summary::TransactionSet]
       # @param folder [String] (nil)
-      # @param headers [Boolean] (false)
       # @return [void]
-      def initialize(folder: nil, headers: false)
-        self.folder  = folder
-        self.headers = headers
+      def initialize(summary, folder: nil)
+        self.summary = summary
+        @folder = folder
       end
 
       def_delegators(
@@ -36,27 +32,21 @@ def initialize(folder: nil, headers: false)
       def self.from_file(path, **kwargs)
         raise Eddy::Errors::Error, "Invalid transaction set definition" unless Eddy::Summary.valid_transaction_set_data?(path)
         data = Eddy::Util.read_json_or_yaml(path)
-        builder = new(**kwargs)
-        builder.summary = Eddy::Summary::TransactionSet.create(data)
-        return builder
+        return new(Eddy::Summary::TransactionSet.create(data), **kwargs)
       end
 
-      # @param summary [Eddy::Summary::TransactionSet]
-      # @param (see #initialize)
-      # @return [Eddy::Build::TransactionSetBuilder]
-      def self.from_summary(summary, **kwargs)
-        builder = new(**kwargs)
-        builder.summary = summary
-        return builder
+      # @return [String]
+      def folder()
+        root_path = @folder || File.join(Eddy::Util.root_dir, "build", "transaction_sets")
+        path = File.join(root_path, self.id.to_s)
+        FileUtils.mkdir_p(path)
+        return path
       end
 
       # @return [String]
       def build()
-        root_path = self.folder || File.join(Eddy::Util.root_dir, "build", "transaction_sets")
-        path = File.join(root_path, self.id.to_s)
-        FileUtils.mkdir_p(path)
-        File.open(File.join(path, "loops.rb"), "a") { |f| f.write(self.render_loops) }
-        return self.ginny_class.generate(path)
+        self.build_loops()
+        return self.ginny_class.generate(self.folder, "#{self.id}.rb")
       end
 
       # @return [String]
@@ -64,13 +54,15 @@ def render()
         return self.ginny_class.render()
       end
 
-      # # @return [String]
-      # def render_loops()
-      #   loops = self.summary.unique_loops.map do |l|
-      #     Eddy::Build::LoopBuilder.from_summary(l, t_set_id: self.normalized_name).ginny_class.render()
-      #   end.join("\n\n")
-      #   return Ginny.mod(("\n" + loops + "\n"), "Eddy", "TransactionSets", self.normalized_name, "Loops")
-      # end
+      # @return [String]
+      def build_loops()
+        FileUtils.mkdir_p(File.join(self.build_path, "loops"))
+        self.summary.unique_loops.each do |looop|
+          File.open(File.join(self.build_path, "loops", "#{looop.normalized_name}.rb"), "a") do |f|
+            f.write(Eddy::Build::Loop.render(looop, self.normalized_name) + "\n")
+          end
+        end
+      end
 
       # @return [Ginny::Class]
       def ginny_class()
@@ -159,7 +151,7 @@ def self.segment_accessor(segment_id)
         return <<~RB.strip
           # (see Eddy::Segments::#{upper})
           #
-          # @yieldparam [Eddy::Segments::#{upper}] #{lower}
+          # @yieldparam [Eddy::Segments::#{upper}]
           # @return [Eddy::Segments::#{upper}]
           def #{upper}()
             yield(@#{lower}) if block_given?
@@ -177,9 +169,9 @@ def self.loop_accessor(summary, t_set_id)
           #
           # @yieldparam [Eddy::TransactionSets::#{t_set_id}::Loops::#{summary.id.upcase}::Repeat]
           # @return [void]
-          def #{summary.var_name.upcase}()
+          def #{summary.var_name.upcase}(&block)
             if block_given?
-              @#{summary.var_name}.repeat()
+              @#{summary.var_name}.repeat(&block)
             else
               raise Eddy::Errors::Error, \"No block given in loop iteration\"
             end
diff --git a/test/eddy/build/loop/base_test.rb b/test/eddy/build/loop/base_test.rb
index d700c30..151c3fe 100644
--- a/test/eddy/build/loop/base_test.rb
+++ b/test/eddy/build/loop/base_test.rb
@@ -21,9 +21,7 @@ def initialize(store)
               super(store, Repeat)
             end
 
-            # Add a repeat of loop N1.
-            #
-            # @yieldparam [Eddy::TransactionSets::TS850::Loops::N1::Repeat] rep
+            # @yieldparam [Eddy::TransactionSets::TS850::Loops::N1::Repeat]
             # @return [void]
             def repeat(&block)
               super(&block)
@@ -53,9 +51,7 @@ def initialize(store)
               super(store, Repeat)
             end
 
-            # Add a repeat of loop IT1.
-            #
-            # @yieldparam [Eddy::TransactionSets::TS810::Loops::IT1::Repeat] rep
+            # @yieldparam [Eddy::TransactionSets::TS810::Loops::IT1::Repeat]
             # @return [void]
             def repeat(&block)
               super(&block)
diff --git a/test/eddy/build/loop/render/it1_test.rb b/test/eddy/build/loop/render/it1_test.rb
index 699453e..cf80a5c 100644
--- a/test/eddy/build/loop/render/it1_test.rb
+++ b/test/eddy/build/loop/render/it1_test.rb
@@ -29,9 +29,7 @@ def initialize(store)
                           super(store, Repeat)
                         end
 
-                        # Add a repeat of loop IT1.
-                        #
-                        # @yieldparam [Eddy::TransactionSets::TS810::Loops::IT1::Repeat] rep
+                        # @yieldparam [Eddy::TransactionSets::TS810::Loops::IT1::Repeat]
                         # @return [void]
                         def repeat(&block)
                           super(&block)
@@ -58,7 +56,7 @@ def initialize(store)
 
                         # (see Eddy::Segments::IT1)
                         #
-                        # @yieldparam [Eddy::Segments::IT1] it1
+                        # @yieldparam [Eddy::Segments::IT1]
                         # @return [Eddy::Segments::IT1]
                         def IT1()
                           yield(@it1) if block_given?
@@ -67,7 +65,7 @@ def IT1()
 
                         # (see Eddy::Segments::CTP)
                         #
-                        # @yieldparam [Eddy::Segments::CTP] ctp
+                        # @yieldparam [Eddy::Segments::CTP]
                         # @return [Eddy::Segments::CTP]
                         def CTP()
                           yield(@ctp) if block_given?
diff --git a/test/eddy/build/loop/render/n1_test.rb b/test/eddy/build/loop/render/n1_test.rb
index e3aaaf1..32bae10 100644
--- a/test/eddy/build/loop/render/n1_test.rb
+++ b/test/eddy/build/loop/render/n1_test.rb
@@ -28,9 +28,7 @@ def initialize(store)
                           super(store, Repeat)
                         end
 
-                        # Add a repeat of loop N1.
-                        #
-                        # @yieldparam [Eddy::TransactionSets::TS850::Loops::N1::Repeat] rep
+                        # @yieldparam [Eddy::TransactionSets::TS850::Loops::N1::Repeat]
                         # @return [void]
                         def repeat(&block)
                           super(&block)
@@ -55,7 +53,7 @@ def initialize(store)
 
                         # (see Eddy::Segments::N1)
                         #
-                        # @yieldparam [Eddy::Segments::N1] n1
+                        # @yieldparam [Eddy::Segments::N1]
                         # @return [Eddy::Segments::N1]
                         def N1()
                           yield(@n1) if block_given?
@@ -64,7 +62,7 @@ def N1()
 
                         # (see Eddy::Segments::N3)
                         #
-                        # @yieldparam [Eddy::Segments::N3] n3
+                        # @yieldparam [Eddy::Segments::N3]
                         # @return [Eddy::Segments::N3]
                         def N3()
                           yield(@n3) if block_given?
@@ -73,7 +71,7 @@ def N3()
 
                         # (see Eddy::Segments::N4)
                         #
-                        # @yieldparam [Eddy::Segments::N4] n4
+                        # @yieldparam [Eddy::Segments::N4]
                         # @return [Eddy::Segments::N4]
                         def N4()
                           yield(@n4) if block_given?
diff --git a/test/eddy/build/loop/repeat_test.rb b/test/eddy/build/loop/repeat_test.rb
index f588789..a06290a 100644
--- a/test/eddy/build/loop/repeat_test.rb
+++ b/test/eddy/build/loop/repeat_test.rb
@@ -24,7 +24,7 @@ def initialize(store)
 
             # (see Eddy::Segments::N1)
             #
-            # @yieldparam [Eddy::Segments::N1] n1
+            # @yieldparam [Eddy::Segments::N1]
             # @return [Eddy::Segments::N1]
             def N1()
               yield(@n1) if block_given?
@@ -33,7 +33,7 @@ def N1()
 
             # (see Eddy::Segments::N3)
             #
-            # @yieldparam [Eddy::Segments::N3] n3
+            # @yieldparam [Eddy::Segments::N3]
             # @return [Eddy::Segments::N3]
             def N3()
               yield(@n3) if block_given?
@@ -42,7 +42,7 @@ def N3()
 
             # (see Eddy::Segments::N4)
             #
-            # @yieldparam [Eddy::Segments::N4] n4
+            # @yieldparam [Eddy::Segments::N4]
             # @return [Eddy::Segments::N4]
             def N4()
               yield(@n4) if block_given?
@@ -77,7 +77,7 @@ def initialize(store)
 
             # (see Eddy::Segments::IT1)
             #
-            # @yieldparam [Eddy::Segments::IT1] it1
+            # @yieldparam [Eddy::Segments::IT1]
             # @return [Eddy::Segments::IT1]
             def IT1()
               yield(@it1) if block_given?
@@ -86,7 +86,7 @@ def IT1()
 
             # (see Eddy::Segments::CTP)
             #
-            # @yieldparam [Eddy::Segments::CTP] ctp
+            # @yieldparam [Eddy::Segments::CTP]
             # @return [Eddy::Segments::CTP]
             def CTP()
               yield(@ctp) if block_given?
diff --git a/test/eddy/build/transaction_set_builder/segment_accessor_test.rb b/test/eddy/build/transaction_set_builder/accessor_test.rb
similarity index 91%
rename from test/eddy/build/transaction_set_builder/segment_accessor_test.rb
rename to test/eddy/build/transaction_set_builder/accessor_test.rb
index 25d2046..7afac7b 100644
--- a/test/eddy/build/transaction_set_builder/segment_accessor_test.rb
+++ b/test/eddy/build/transaction_set_builder/accessor_test.rb
@@ -8,7 +8,7 @@ def test_segment_accessor
         want = <<~RB.strip
           # (see Eddy::Segments::CTT)
           #
-          # @yieldparam [Eddy::Segments::CTT] ctt
+          # @yieldparam [Eddy::Segments::CTT]
           # @return [Eddy::Segments::CTT]
           def CTT()
             yield(@ctt) if block_given?
@@ -24,9 +24,9 @@ def test_loop_accessor
           #
           # @yieldparam [Eddy::TransactionSets::TS810::Loops::N1::Repeat]
           # @return [void]
-          def L_N1()
+          def L_N1(&block)
             if block_given?
-              @l_n1.repeat()
+              @l_n1.repeat(&block)
             else
               raise Eddy::Errors::Error, "No block given in loop iteration"
             end
diff --git a/test/eddy/build/transaction_set_builder/ts810_test.rb b/test/eddy/build/transaction_set_builder/ts810_test.rb
index 57038af..7276454 100644
--- a/test/eddy/build/transaction_set_builder/ts810_test.rb
+++ b/test/eddy/build/transaction_set_builder/ts810_test.rb
@@ -52,7 +52,7 @@ def initialize(store)
 
                   # (see Eddy::Segments::BIG)
                   #
-                  # @yieldparam [Eddy::Segments::BIG] big
+                  # @yieldparam [Eddy::Segments::BIG]
                   # @return [Eddy::Segments::BIG]
                   def BIG()
                     yield(@big) if block_given?
@@ -61,7 +61,7 @@ def BIG()
 
                   # (see Eddy::Segments::REF)
                   #
-                  # @yieldparam [Eddy::Segments::REF] ref
+                  # @yieldparam [Eddy::Segments::REF]
                   # @return [Eddy::Segments::REF]
                   def REF()
                     yield(@ref) if block_given?
@@ -72,9 +72,9 @@ def REF()
                   #
                   # @yieldparam [Eddy::TransactionSets::TS810::Loops::N1::Repeat]
                   # @return [void]
-                  def L_N1()
+                  def L_N1(&block)
                     if block_given?
-                      @l_n1.repeat()
+                      @l_n1.repeat(&block)
                     else
                       raise Eddy::Errors::Error, "No block given in loop iteration"
                     end
@@ -83,7 +83,7 @@ def L_N1()
 
                   # (see Eddy::Segments::DTM)
                   #
-                  # @yieldparam [Eddy::Segments::DTM] dtm
+                  # @yieldparam [Eddy::Segments::DTM]
                   # @return [Eddy::Segments::DTM]
                   def DTM()
                     yield(@dtm) if block_given?
@@ -94,9 +94,9 @@ def DTM()
                   #
                   # @yieldparam [Eddy::TransactionSets::TS810::Loops::IT1::Repeat]
                   # @return [void]
-                  def L_IT1()
+                  def L_IT1(&block)
                     if block_given?
-                      @l_it1.repeat()
+                      @l_it1.repeat(&block)
                     else
                       raise Eddy::Errors::Error, "No block given in loop iteration"
                     end
@@ -105,7 +105,7 @@ def L_IT1()
 
                   # (see Eddy::Segments::TDS)
                   #
-                  # @yieldparam [Eddy::Segments::TDS] tds
+                  # @yieldparam [Eddy::Segments::TDS]
                   # @return [Eddy::Segments::TDS]
                   def TDS()
                     yield(@tds) if block_given?
@@ -114,7 +114,7 @@ def TDS()
 
                   # (see Eddy::Segments::CAD)
                   #
-                  # @yieldparam [Eddy::Segments::CAD] cad
+                  # @yieldparam [Eddy::Segments::CAD]
                   # @return [Eddy::Segments::CAD]
                   def CAD()
                     yield(@cad) if block_given?
@@ -125,9 +125,9 @@ def CAD()
                   #
                   # @yieldparam [Eddy::TransactionSets::TS810::Loops::SAC::Repeat]
                   # @return [void]
-                  def L_SAC()
+                  def L_SAC(&block)
                     if block_given?
-                      @l_sac.repeat()
+                      @l_sac.repeat(&block)
                     else
                       raise Eddy::Errors::Error, "No block given in loop iteration"
                     end
@@ -136,7 +136,7 @@ def L_SAC()
 
                   # (see Eddy::Segments::CTT)
                   #
-                  # @yieldparam [Eddy::Segments::CTT] ctt
+                  # @yieldparam [Eddy::Segments::CTT]
                   # @return [Eddy::Segments::CTT]
                   def CTT()
                     yield(@ctt) if block_given?
@@ -148,7 +148,7 @@ def CTT()
             end
           end
         RB
-        have = Eddy::Build::TransactionSetBuilder.from_summary(@summary).ginny_class.render()
+        have = Eddy::Build::TransactionSetBuilder.new(@summary).ginny_class.render()
         assert_equal(want, have)
       end
 
diff --git a/test/eddy/build/transaction_set_builder/ts850_test.rb b/test/eddy/build/transaction_set_builder/ts850_test.rb
index 2863851..cf553aa 100644
--- a/test/eddy/build/transaction_set_builder/ts850_test.rb
+++ b/test/eddy/build/transaction_set_builder/ts850_test.rb
@@ -44,7 +44,7 @@ def initialize(store)
 
                   # (see Eddy::Segments::BEG)
                   #
-                  # @yieldparam [Eddy::Segments::BEG] beg
+                  # @yieldparam [Eddy::Segments::BEG]
                   # @return [Eddy::Segments::BEG]
                   def BEG()
                     yield(@beg) if block_given?
@@ -53,7 +53,7 @@ def BEG()
 
                   # (see Eddy::Segments::TD5)
                   #
-                  # @yieldparam [Eddy::Segments::TD5] td5
+                  # @yieldparam [Eddy::Segments::TD5]
                   # @return [Eddy::Segments::TD5]
                   def TD5()
                     yield(@td5) if block_given?
@@ -64,9 +64,9 @@ def TD5()
                   #
                   # @yieldparam [Eddy::TransactionSets::TS850::Loops::N1::Repeat]
                   # @return [void]
-                  def L_N1()
+                  def L_N1(&block)
                     if block_given?
-                      @l_n1.repeat()
+                      @l_n1.repeat(&block)
                     else
                       raise Eddy::Errors::Error, "No block given in loop iteration"
                     end
@@ -77,9 +77,9 @@ def L_N1()
                   #
                   # @yieldparam [Eddy::TransactionSets::TS850::Loops::PO1::Repeat]
                   # @return [void]
-                  def L_PO1()
+                  def L_PO1(&block)
                     if block_given?
-                      @l_po1.repeat()
+                      @l_po1.repeat(&block)
                     else
                       raise Eddy::Errors::Error, "No block given in loop iteration"
                     end
@@ -88,7 +88,7 @@ def L_PO1()
 
                   # (see Eddy::Segments::CTT)
                   #
-                  # @yieldparam [Eddy::Segments::CTT] ctt
+                  # @yieldparam [Eddy::Segments::CTT]
                   # @return [Eddy::Segments::CTT]
                   def CTT()
                     yield(@ctt) if block_given?
@@ -100,7 +100,7 @@ def CTT()
             end
           end
         RB
-        have = Eddy::Build::TransactionSetBuilder.from_summary(@summary).ginny_class.render()
+        have = Eddy::Build::TransactionSetBuilder.new(@summary).ginny_class.render()
         assert_equal(want, have)
       end