writestream.fs

(* In this weird case I need to write a stream but also keep track of how long ago a linefeed was written *)

    member s.WriteStream (from:Stream) =
      use reader = new StreamReader(from)
      let mutable buffer = Array.zeroCreate<char>(BUFFER_LENGTH)
      let mutable len = 0
      while not reader.EndOfStream do
        len <- reader.ReadBlock(buffer, 0, buffer.Length)
        s.OutputWriter.Write(buffer, 0, len) 
        (* Now, walk backwards through the buffer looking for linefeeds *)
        match 
          buffer 
          |> Array.rev 
          |> Array.tryFindIndex ((=) '\n')
          with
        | Some index -> s.Column := index - (BUFFER_LENGTH - len)
        | None       -> s.Column := !s.Column + len