Mercurial > urweb
annotate tests/datatypeP.ur @ 1431:4a6f84092399
Represent 'unit' as C 'int'; change pattern match compilation to avoid 'goto'; change Postgres prepared statement compilation to make life easier for the GCC escape analysis; all this in support of better tail call optimization
| author | Adam Chlipala <adam@chlipala.net> |
|---|---|
| date | Thu, 10 Mar 2011 18:51:15 -0500 |
| parents | 71bafe66dbe1 |
| children |
| rev | line source |
|---|---|
| adamc@191 | 1 datatype option a = None | Some of a |
| adamc@191 | 2 |
| adamc@191 | 3 val none : option int = None |
| adamc@191 | 4 val some_1 : option int = Some 1 |
| adamc@191 | 5 |
| adamc@191 | 6 val f = fn t ::: Type => fn x : option t => |
| adamc@191 | 7 case x of None => None | Some x => Some (Some x) |
| adamc@191 | 8 |
| adamc@191 | 9 val none_again = f none |
| adamc@191 | 10 val some_1_again = f some_1 |
| adamc@193 | 11 |
| adamc@193 | 12 val show = fn t ::: Type => fn x : option t => case x of None => "None" | Some _ => "Some" |
| adamc@193 | 13 |
| adamc@193 | 14 val page = fn x => <html><body> |
| adamc@193 | 15 {cdata (show x)} |
| adamc@193 | 16 </body></html> |
| adamc@193 | 17 |
| adamc@193 | 18 val main : unit -> page = fn () => <html><body> |
| adamc@193 | 19 <li><a link={page none_again}>None</a></li> |
| adamc@193 | 20 <li><a link={page some_1_again}>Some 1</a></li> |
| adamc@193 | 21 </body></html> |