Ur/Web: tests/policy2.ur annotate

Interpret 'table' signature items more flexibly, automatically adding (Ur) constraints to support a kind of subtyping over (SQL) constraint sets

author	Adam Chlipala <adam@chlipala.net>
date	Mon, 04 Nov 2013 15:14:23 -0500
parents	d5ecceb7d1a1
children

rev	line source
adamc@1236	1 type fruit = int
adamc@1236	2 table fruit : { Id : fruit, Nam : string, Weight : float, Secret : string }
adamc@1236	3 PRIMARY KEY Id,
adamc@1236	4 CONSTRAINT Nam UNIQUE Nam
adamc@1236	5
adamc@1236	6 (* Everyone may knows IDs and names. *)
adamc@1236	7 policy sendClient (SELECT fruit.Id, fruit.Nam
adamc@1236	8 FROM fruit)
adamc@1236	9
adamc@1236	10 (* The weight is sensitive information; you must know the secret. *)
adamc@1236	11 policy sendClient (SELECT fruit.Weight, fruit.Secret
adamc@1236	12 FROM fruit
adamc@1236	13 WHERE known(fruit.Secret))
adamc@1236	14
adamc@1236	15 fun main () =
adamc@1236	16 x1 <- queryX (SELECT fruit.Id, fruit.Nam
adamc@1236	17 FROM fruit
adamc@1236	18 WHERE fruit.Nam = "apple")
adamc@1236	19 (fn x => <xml><li>{[x.Fruit.Id]}: {[x.Fruit.Nam]}</li></xml>);
adamc@1236	20 return <xml><body>
adamc@1236	21 <ul>{x1}</ul>
adamc@1236	22 </body></xml>

Mercurial > urweb