adamc@198: datatype option a = None | Some of a
adamc@198: 
adamc@198: val none_Hi : option string = None
adamc@198: val some_Hi = Some "Hi"
adamc@198: val none_some_Hi : option (option string) = None
adamc@198: val some_some_Hi = Some some_Hi
adamc@198: 
adamc@198: val show = fn x => case x of None => "None" | Some x => x
adamc@198: 
adamc@198: val show2 = fn x => case x of None => "None'" | Some x => show x
adamc@198: 
adamc@284: val page = fn x => return <html><body>
adamc@198:         {cdata (show x)}
adamc@198: </body></html>
adamc@198: 
adamc@284: val page2 = fn x => return <html><body>
adamc@198:         {cdata (show2 x)}
adamc@198: </body></html>
adamc@198: 
adamc@284: val main : unit -> transaction page = fn () => return <html><body>
adamc@198:         <li><a link={page none_Hi}>None1</a></li>
adamc@198:         <li><a link={page some_Hi}>Some1</a></li>
adamc@198:         <li><a link={page2 none_some_Hi}>None2</a></li>
adamc@198:         <li><a link={page2 some_some_Hi}>Some2</a></li>
adamc@198: </body></html>