Ur/Web: demo/sum.ur annotate

Tag NULLs with their types in SQL, to help the DBMS do type inference

author	Adam Chlipala <adam@chlipala.net>
date	Sat, 04 Jul 2015 19:24:26 -0400
parents	8d3aa6c7cee0
children

rev	line source
adamc@823	1 fun sum [fs ::: {Unit}] (fl : folder fs) (x : $(mapU int fs)) =
adamc@1093	2 @foldUR [int] [fn _ => int]
adamc@1093	3 (fn [nm :: Name] [rest :: {Unit}] [[nm] ~ rest] n acc => n + acc)
adamc@1093	4 0 fl x
adamc@411	5
adamc@411	6 fun main () = return <xml><body>
adamc@633	7 {[sum {}]}<br/>
adamc@633	8 {[sum {A = 0, B = 1}]}<br/>
adamc@633	9 {[sum {C = 2, D = 3, E = 4}]}
adamc@411	10 </body></xml>

Mercurial > urweb