Mercurial > urweb

view demo/tcSum.ur @ 2009:799be3911ce3

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Monadic bind supports patterns
author Adam Chlipala <adam@chlipala.net>
date Fri, 02 May 2014 17:16:02 -0400
parents 8d3aa6c7cee0
children
line wrap: on
line source
fun sum [t] (_ : num t) [fs ::: {Unit}] (fl : folder fs) (x : $(mapU t fs)) =
    @foldUR [t] [fn _ => t]
     (fn [nm :: Name] [rest :: {Unit}] [[nm] ~ rest] n acc => n + acc)
     zero fl x

fun main () = return <xml><body>
  {[sum {A = 0, B = 1}]}<br/>
  {[sum {C = 2.1, D = 3.2, E = 4.3}]}
</body></xml>