Ur/Web: tests/where.ur annotate

Tutorial: up to First-Class Polymorphism

author	Adam Chlipala <adam@chlipala.net>
date	Sun, 17 Jul 2011 11:00:04 -0400
parents	8bb46d87b074
children

rev	line source
adamc@209	1 table t1 : {A : int, B : string, C : float}
adamc@209	2 table t2 : {A : float, D : int}
adamc@209	3
adamc@209	4 val q1 = (SELECT * FROM t1)
adamc@209	5 val q2 = (SELECT * FROM t1 WHERE TRUE)
adamc@209	6 val q3 = (SELECT * FROM t1 WHERE FALSE)
adamc@210	7 val q4 = (SELECT * FROM t1 WHERE {True})
adamc@219	8 val q5 = (SELECT * FROM t1 WHERE {1} = {1})
adamc@219	9 val q6 = (SELECT * FROM t1 WHERE {"Hi"} < {"Bye"})
adamc@279	10 val q7 = (SELECT * FROM t1 WHERE {1} = {1} AND NOT ({"Hi"} <= {"Bye"}))
adamc@222	11 val q8 = (SELECT * FROM t1 WHERE t1.A = 1 OR t1.C < 3.0)
adamc@255	12
adamc@255	13 datatype list a = Nil \| Cons of a * list a
adamc@255	14
adamc@255	15 val r1 : transaction (list {A : int, B : string, C : float}) =
adamc@264	16 query q7
adamc@255	17 (fn fs acc => return (Cons (fs.T1, acc)))
adamc@255	18 Nil
adamc@255	19
adamc@255	20 val r2 : transaction string =
adamc@255	21 ls <- r1;
adamc@255	22 return (case ls of
adamc@255	23 Nil => "Problem"
adamc@255	24 \| Cons ({B = b, ...}, _) => b)
adamc@255	25
adamc@255	26 val main : unit -> transaction page = fn () =>
adamc@255	27 s <- r2;
adamc@255	28 return <html><body>
adamc@255	29 {cdata s}
adamc@255	30 </body></html>

Mercurial > urweb