view demo/sum.ur @ 412:df4cbd90a26e

Infering sum rows
author Adam Chlipala <adamc@hcoop.net>
date Tue, 21 Oct 2008 19:31:11 -0400
parents 06fcddcd20d3
children 6a0e54400805
line wrap: on
line source
fun sum (fs ::: {Unit}) (x : $(mapUT int fs)) =
    foldUR [int] [fn _ => int]
    (fn (nm :: Name) (rest :: {Unit}) [[nm] ~ rest] n acc => n + acc)
    0 [fs] x

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