anchor.diff:      | "--packages" -> Some TokenOption.Packages
       | "--test" -> Some TokenOption.Test
       | "--full" -> Some TokenOption.Full
  -    | "--use" -> Some TokenOption.Use
  +    | "--ref" -> Some TokenOption.Ref
       | _ -> None
   
   type private Token =
  
positive.code:         [MainCommand.Workspace; MainCommand.Checkout], "checkout <version> : checkout workspace to version"
          [MainCommand.Workspace; MainCommand.Branch], "branch [<branch>] : switch to branch"
          [MainCommand.Workspace; MainCommand.InstallPackage], "install : install packages"
          [MainCommand.View; MainCommand.AddView], "view [--down] [--up] [--modified] [--app <app-wildcard>] [--static] [--test] <viewId> <viewId-wildcard>+ : add repositories to view"
          [MainCommand.View; MainCommand.OpenView], "open <viewId> : open view with your favorite ide"
          [MainCommand.View; MainCommand.BuildView], "build [--mt] [--debug] [--version <version>] [<viewId>] : build view"
          [MainCommand.View; MainCommand.RebuildView], "rebuild [--mt] [--debug] [--version <version>] [<viewId>] : rebuild view (clean & build)"
  
negative.code:     | Packages
      | Test
      | Full
      | Ref
  
  let private (|TokenOption|_|) (token : string) =
      match token with
  