Ur/Web: tests/dlist.ur annotate

Fix a read-after-free bug using a timestamp check

author	Adam Chlipala <adam@chlipala.net>
date	Thu, 19 Nov 2015 13:18:58 -0500
parents	20c083327364
children

rev	line source
adamc@601	1 datatype dlist = Nil \| Cons of string * source dlist
adamc@601	2
adamc@601	3 fun delist dl =
adamc@601	4 case dl of
adamc@601	5 Nil => <xml>[]</xml>
adamc@604	6 \| Cons (x, s) => <xml>{[x]} :: ({delistSource s})</xml>
adamc@601	7
adamc@601	8 and delistSource s = <xml><dyn signal={dl <- signal s; return (delist dl)}/></xml>
adamc@601	9
adamc@601	10 fun main () : transaction page =
adamc@601	11 ns <- source Nil;
adamc@601	12 s <- source ns;
adamc@601	13 tb <- source "";
adamc@601	14 return <xml><body>
adamc@601	15 <dyn signal={s <- signal s; return (delistSource s)}/><br/>
adamc@601	16 <br/>
adamc@601	17 <ctextbox source={tb}/>
adamc@601	18 <button value="Add" onclick={hd <- get tb;
adamc@601	19 tl <- get s;
adamc@601	20 s' <- source (Cons (hd, tl));
adamc@601	21 set s s'}/>
adamc@603	22 <button value="Reset" onclick={set s ns}/>
adamc@601	23 </body></xml>

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