1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
datatype dlist'' t =
Nil
| Cons of t * source (dlist'' t)
datatype dlist' t =
Empty
| Nonempty of { Head : dlist'' t, Tail : source (source (dlist'' t)) }
con dlist t = source (dlist' t)
type position = transaction unit
fun headPos [t] (dl : dlist t) =
dl' <- get dl;
case dl' of
Nonempty { Head = Cons (_, tl), Tail = tl' } =>
cur <- get tl;
set dl (case cur of
Nil => Empty
| _ => Nonempty {Head = cur, Tail = tl'})
| _ => return ()
fun tailPos [t] (cur : source (dlist'' t)) new tail =
new' <- get new;
set cur new';
case new' of
Nil => set tail cur
| _ => return ()
val create [t] = source Empty
fun clear [t] (s : dlist t) = set s Empty
fun append [t] dl v =
dl' <- get dl;
case dl' of
Empty =>
tl <- source Nil;
tl' <- source tl;
set dl (Nonempty {Head = Cons (v, tl), Tail = tl'});
return (headPos dl)
| Nonempty {Tail = tl, ...} =>
cur <- get tl;
new <- source Nil;
set cur (Cons (v, new));
set tl new;
return (tailPos cur new tl)
fun renderDyn [ctx] [ctx ~ body] [t] (f : t -> position -> xml (ctx ++ body) [] []) filter dl = <xml>
<dyn signal={dl' <- signal dl;
return (case dl' of
Empty => <xml/>
| Nonempty {Head = hd, Tail = tlTop} =>
let
fun render' prev dl'' =
case dl'' of
Nil => <xml/>
| Cons (v, tl) =>
let
val pos = case prev of
None => headPos dl
| Some prev => tailPos prev tl tlTop
in
<xml><dyn signal={b <- filter v;
return (if b then
f v pos
else
<xml/>)}/>
<dyn signal={tl' <- signal tl;
return (render' (Some tl) tl')}/></xml>
end
in
render' None hd
end)}/>
</xml>
fun renderFlat [ctx] [ctx ~ body] [t] (f : t -> position -> xml (ctx ++ body) [] []) filter ls =
List.mapX (fn p => f p.1 p.2) ls
val split [t] =
let
fun split' acc (ls : list t) =
case ls of
[] => acc
| x1 :: [] => (x1 :: acc.1, acc.2)
| x1 :: x2 :: ls => split' (x1 :: acc.1, x2 :: acc.2) ls
in
split' ([], [])
end
fun merge [t] (cmp : t -> t -> signal bool) =
let
fun merge' acc (ls1 : list t) (ls2 : list t) =
case (ls1, ls2) of
([], _) => return (List.revAppend acc ls2)
| (_, []) => return (List.revAppend acc ls1)
| (x1 :: ls1', x2 :: ls2') =>
b <- cmp x1 x2;
if b then
merge' (x1 :: acc) ls1' ls2
else
merge' (x2 :: acc) ls1 ls2'
in
merge' []
end
fun sort [t] (cmp : t -> t -> signal bool) =
let
fun sort' (ls : list t) =
case ls of
[] => return ls
| _ :: [] => return ls
| _ =>
let
val (ls1, ls2) = split ls
in
ls1' <- sort' ls1;
ls2' <- sort' ls2;
merge cmp ls1' ls2'
end
in
sort'
end
fun render [ctx] [ctx ~ body] [t] f (r : {Filter : t -> signal bool,
Sort : signal (option (t -> t -> signal bool))}) dl = <xml>
<dyn signal={cmp <- r.Sort;
case cmp of
None => return (renderDyn f r.Filter dl)
| Some cmp =>
dl' <- signal dl;
elems <- (case dl' of
Empty => return []
| Nonempty {Head = hd, Tail = tlTop} =>
let
fun listOut prev dl'' acc =
case dl'' of
Nil => return acc
| Cons (v, tl) =>
let
val pos = case prev of
None => headPos dl
| Some prev => tailPos prev tl tlTop
in
tl' <- signal tl;
listOut (Some tl) tl' ((v, pos) :: acc)
end
in
listOut None hd []
end);
elems <- sort (fn v1 v2 => cmp v1.1 v2.1) elems;
return (renderFlat f r.Filter elems)}/>
</xml>
fun delete pos = pos
fun elements' [t] (dl'' : dlist'' t) =
case dl'' of
Nil => return []
| Cons (x, dl'') =>
dl'' <- signal dl'';
tl <- elements' dl'';
return (x :: tl)
fun elements [t] (dl : dlist t) =
dl' <- signal dl;
case dl' of
Empty => return []
| Nonempty {Head = hd, ...} => elements' hd
fun foldl [t] [acc] (f : t -> acc -> signal acc) =
let
fun foldl'' (i : acc) (dl : dlist'' t) : signal acc =
case dl of
Nil => return i
| Cons (v, dl') =>
dl' <- signal dl';
i' <- f v i;
foldl'' i' dl'
fun foldl' (i : acc) (dl : dlist t) : signal acc =
dl <- signal dl;
case dl of
Empty => return i
| Nonempty {Head = dl, ...} => foldl'' i dl
in
foldl'
end
|
