Ur/Web: tests/limit.ur annotate

Tutorial: hyperlinks for metaprogramming and row types

author	Adam Chlipala <adam@chlipala.net>
date	Wed, 20 Jul 2011 08:14:49 -0400
parents	02e1870a0516
children

rev	line source
adamc@231	1 table t : {A : int, B : string, C : float}
adamc@231	2
adamc@231	3 val q1 = (SELECT * FROM t LIMIT 42)
adamc@231	4 val q2 = fn n => (SELECT * FROM t LIMIT {n})
adamc@232	5
adamc@232	6 val q3 = (SELECT * FROM t OFFSET 3)
adamc@232	7 val q4 = fn n => fn m => (SELECT * FROM t LIMIT {n} OFFSET {m})
adamc@262	8
adamc@262	9
adamc@262	10 datatype list a = Nil \| Cons of a * list a
adamc@262	11
adamc@262	12 val r1 : transaction (list {A : int, B : string, C : float}) =
adamc@263	13 query (q4 3 7)
adamc@262	14 (fn fs acc => return (Cons (fs.T, acc)))
adamc@262	15 Nil
adamc@262	16
adamc@262	17 val r2 : transaction string =
adamc@262	18 ls <- r1;
adamc@262	19 return (case ls of
adamc@262	20 Nil => "Problem"
adamc@262	21 \| Cons ({B = b, ...}, _) => b)
adamc@262	22
adamc@262	23 val main : unit -> transaction page = fn () =>
adamc@262	24 s <- r2;
adamc@262	25 return <html><body>
adamc@262	26 {cdata s}
adamc@262	27 </body></html>

Mercurial > urweb