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comparison demo/listEdit.ur @ 646:fb2a0e76dcef

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ListEdit demo, minus prose
author Adam Chlipala <adamc@hcoop.net>
date Tue, 10 Mar 2009 12:44:40 -0400
parents
children e6bc6bbd7a32
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645:1b571a05874c 646:fb2a0e76dcef
1 datatype rlist = Nil | Cons of {Data : source string,
2 NewData : source string,
3 Tail : source rlist}
4
5 fun showString ss =
6 s <- signal ss;
7 return <xml>{[s]}</xml>
8
9 fun show rls =
10 v <- signal rls;
11 show' v
12
13 and show' rl =
14 case rl of
15 Nil => return <xml/>
16 | Cons {Data = ss, NewData = ss', Tail = rls} => return <xml>
17 <dyn signal={showString ss}/>
18 <button value="Change to:" onclick={s <- get ss'; set ss s}/>
19 <ctextbox source={ss'}/><br/>
20 <dyn signal={show rls}/>
21 </xml>
22
23 fun main () =
24 head <- source Nil;
25 tailP <- source head;
26 data <- source "";
27
28 let
29 fun add () =
30 data <- get data;
31 data <- source data;
32 ndata <- source "";
33 tail <- get tailP;
34 tail' <- source Nil;
35
36 let
37 val cons = Cons {Data = data, NewData = ndata, Tail = tail'}
38 in
39 set tail cons;
40 set tailP tail';
41
42 head' <- get head;
43 case head' of
44 Nil => set head cons
45 | _ => return ()
46 end
47 in
48 return <xml><body>
49 <ctextbox source={data}/> <button value="Add" onclick={add ()}/><br/>
50 <br/>
51
52 <dyn signal={show head}/>
53 </body></xml>
54 end