withString.fs

let bindArgumentsAndGenerateScript (args : Dictionary<string, _>) t =
  let generateCall c = c |> bindArgument args <!> (sprintf "CALL %s")
  let appendLine (stringBuilder : string) s = stringBuilder + s + "\n"

  let generateTryCatchBlock (i, c) s =
    let successLabel = sprintf "_success_%d" i
    let errorLabel = sprintf "_error_%d" i
    controlled {
      let! sb = c.Try |> generateCall <!> appendLine s
      // ...
      let! sb = c.Catch |> Option.map generateCall |> getOrElse (Success "") <!> appendLine sb
      // ...
      return sprintf "" |>  appendLine sb
    }

  controlled {
    let! sb = t.TryCatchCommands |> List.mapi (fun i c -> (i, c)) |> List.fold (foldM generateTryCatchBlock) (Success "")
    return! sprintf ":%s" finallyLabel |> Success <!> appendLine sb
  }

withStringBuilder.fs

let bindArgumentsAndGenerateScript (args : Dictionary<string, _>) t =
  let generateCall c = c |> bindArgument args <!> (sprintf "CALL %s")
  let appendLine (stringBuilder : StringBuilder) s = stringBuilder.AppendLine(s)

  let generateTryCatchBlock (i, c) sb =
    let successLabel = sprintf "_success_%d" i
    let errorLabel = sprintf "_error_%d" i
    controlled {
      let! sb = c.Try |> generateCall <!> appendLine sb
      // ...
      let! sb = c.Catch |> Option.map generateCall |> getOrElse (Success "") <!> appendLine sb
      // ...
      return sprintf "" |>  appendLine sb
    }

  controlled {
    let foldrM f z = List.fold (fun m a -> m >>= f a) (Success z)
    let! sb = t.TryCatchCommands |> List.mapi (fun i c -> (i, c)) |> foldrM generateTryCatchBlock (StringBuilder())
    return! sprintf ":%s" finallyLabel |> Success <!> appendLine sb
  }