循环在SML/NJ中的文本文件的行

这样的事情怎么样:

fun readlist (infile : string) = let
  val ins = TextIO.openIn infile
  fun loop ins =
   case TextIO.inputLine ins of
      SOME line => line :: loop ins
    | NONE      => []
in
  loop ins before TextIO.closeIn ins
end