blob: 3cc270e8577299b1b5748ca81e81ec9e1a7a9987 (
plain) (
blame)
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
|
(define-library (csc set)
(export
*empty-set*
difference
empty?
intersection
make-comparer
member?
set
set->list
set=?
set?
subset?
union)
(import (scheme base)
(only (csc hash-map)
delete
insert
lookup
make-map
map-for-each
map?
merge)
(only (csc loop)
loop
return))
(begin
(define-record-type <empty-set>
(make-empty-set)
empty-set?)
(define *empty-set* (make-empty-set))
(define (set? x)
(or (map? x)
(empty-set? x)))
(define-record-type <not-empty>
(make-not-empty)
not-empty?)
(define *not-empty* (make-not-empty))
(define (empty? s)
(or (empty-set? s)
(guard (e ((not-empty? e) #f))
(map-for-each (lambda (k v)
(raise *not-empty*))
s)
#t)))
(define-record-type <comparer>
(make-comparer hash cmp)
comparer?
(hash comparer-hash)
(cmp comparer-cmp))
(define (set k . l)
(loop with m = (make-map (comparer-hash k) (comparer-cmp k))
for x in l
do (set! m (insert m x #t))
finally (return m)))
(define (member? x s)
(and (not (empty-set? s))
(lookup s x #f)))
(define (union . s*)
(define non-empty (loop for s in s*
unless (empty-set? s)
collect s))
(if (null? non-empty)
*empty-set*
(apply merge non-empty)))
(define (intersect2 s1 s2)
(map-for-each (lambda (k v)
(unless (member? k s2)
(set! s1 (delete s1 k))))
s1)
s1)
(define (intersection . s*)
(if (or (loop for s in s*
if (empty-set? s)
return #t
finally (return #f))
(null? s*))
*empty-set*
(loop for s in s*
for result = s then (intersect2 result s)
finally (return result))))
(define (difference s1 s2)
(cond
((empty? s2) s1)
((empty? s1) *empty-set*)
(else
(map-for-each (lambda (k v)
(set! s1 (delete s1 k)))
s2)
s1)))
(define-record-type <not-subset>
(make-not-subset)
not-subset?)
(define *not-subset* (make-not-subset))
(define (subset? s1 s2)
(cond
((empty? s1) #t)
((empty? s2) #f)
(else
(guard (e ((not-subset? e) #f))
(map-for-each (lambda (k v)
(unless (member? k s2)
(raise *not-subset*)))
s1)
#t))))
(define (set->list s)
(if (empty-set? s)
'()
(let ((l '()))
(map-for-each (lambda (k v)
(set! l (cons k l)))
s)
l)))
(define (set=? . s*)
(if (null? s*)
#t
(loop with s1 = (car s*)
for s in (cdr s*)
unless (and (subset? s s1)
(subset? s1 s))
return #f
finally (return #t))))))
|
