🚀 go-pugleaf

Regarding SML, kff@dentex.tds.kth.se (Karl-Filip Faxen) says:

>|> and it seems to be difficult to indent automatically as well.
>
>In an Emacs mode, perhaps. In a pretty printer, certainly not (I've
>written one).
>
>Cheers,
>         Karl-Filip

I never even thought that writing a pretty-printer for SML was a
feasible undertaking.  Consider the following program:

--------------------------------------------------------------
datatype foo = Alpha of int | Beta of real | Gamma of string;
datatype bar = Happy of int | Dopey of real | Grumpy of string;

fun testcase (x,y) =
  case x of
    Alpha _ => ()
  | Beta _ =>
      case y of
        Happy _ => ()
      | Dopey _ => ()
      | Grumpy _ => ()
  | Gamma _ => ();       (* Hmmm... *)
--------------------------------------------------------------

Any pretty-printer that can correctly indent the last line of testcase
has to be able to discriminate between the constructors of foo and the
constructors of bar!!  Does your pretty-printer really do this?  If
so, I'm very impressed.

				Jon