Pipes refactoring, Fixes in type checker

ASTPlayground/MainForm.fmx

@@ -8,6 +8,7 @@ object Form1: TForm1
   FormFactor.Height = 480
   FormFactor.Devices = [Desktop]
   OnCreate = FormCreate
+  OnDestroy = FormDestroy
   DesignerMasterStyle = 0
   object Panel1: TPanel
     Align = MostLeft
@@ -286,4 +287,20 @@ object Form1: TForm1
     Text = 'Save'
     OnClick = SaveScriptButtonClick
   end
+  object Timer1: TTimer
+    Interval = 250
+    OnTimer = Timer1Timer
+    Left = 992
+    Top = 216
+  end
+  object WatchLabel: TLabel
+    Anchors = [akRight, akBottom]
+    Position.X = 1097.000000000000000000
+    Position.Y = 856.000000000000000000
+    Size.Width = 289.000000000000000000
+    Size.Height = 17.000000000000000000
+    Size.PlatformDefault = False
+    Text = 'watcher: ..............'
+    TabOrder = 9
+  end
 end