Mercurial > urweb

view tests/datatypeP.ur @ 1839:d8c260bcc1f9

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fix determination of MySQL timestamp hour fields (may still be wrong once DST bit flips)
author Adam Chlipala <adam@chlipala.net>
date Thu, 13 Dec 2012 17:51:34 -0500
parents 71bafe66dbe1
children
line wrap: on
line source
datatype option a = None | Some of a

val none : option int = None
val some_1 : option int = Some 1

val f = fn t ::: Type => fn x : option t =>
        case x of None => None | Some x => Some (Some x)

val none_again = f none
val some_1_again = f some_1

val show = fn t ::: Type => fn x : option t => case x of None => "None" | Some _ => "Some"

val page = fn x => <html><body>
        {cdata (show x)}
</body></html>

val main : unit -> page = fn () => <html><body>
        <li><a link={page none_again}>None</a></li>
        <li><a link={page some_1_again}>Some 1</a></li>
</body></html>