Mercurial > urweb

view demo/sum.ur @ 711:7292bcb7c02d

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Made type class system very general; demo compiles
author Adam Chlipala <adamc@hcoop.net>
date Thu, 09 Apr 2009 12:31:56 -0400
parents aa2290c32ce2
children 669ac5e9a69e
line wrap: on
line source
fun sum (fs ::: {Unit}) (fl : folder fs) (x : $(mapU int fs)) =
    foldUR [int] [fn _ => int]
    (fn (nm :: Name) (rest :: {Unit}) [[nm] ~ rest] n acc => n + acc)
    0 [fs] fl x

fun main () = return <xml><body>
  {[sum {}]}<br/>
  {[sum {A = 0, B = 1}]}<br/>
  {[sum {C = 2, D = 3, E = 4}]}
</body></xml>