-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathbdd.rkt
187 lines (153 loc) · 6.82 KB
/
bdd.rkt
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
#lang racket
;;
;; bdd-racket: experimental library implementing BDDs in racket
;; programming language (https://racket-lang.org)
;;
;; This source code is released under MIT License
;; Copyright (c) 2016 Peter Cerman (https://github.com/pcerman)
;;
(require "utils.rkt"
(only-in eopl define-datatype cases))
(provide bdd-node
bdd-node?
bdd-node-var
bdd-node-lo
bdd-node-hi
zdd
zdd?
zdd-value
zdd-nodes
robdd
robdd?
robdd-value
robdd-nodes
bdd->tgf
bdd->tree)
;;****************************************************************************
(struct bdd-node (var lo hi) #:transparent)
(define-datatype zdd zdd?
(zdd-value (v boolean?))
(zdd-nodes (ns vector?)))
(define-datatype robdd robdd?
(robdd-value (v boolean?))
(robdd-nodes (ns vector?)))
;;****************************************************************************
(define (bdd->tgf dd [port #f] [var-names #f] [t-vals #f])
(define t-nodes (if (length-2? t-vals) (list->vector t-vals) '#("._." ".T.")))
(define (t-node v)
(vector-ref t-nodes (if v 1 0)))
(define (bdd-print fn)
(cond [(port? port) (fn port)]
[(string? port) (let ([filename port])
(when (file-exists? filename)
(delete-file filename))
(call-with-output-file filename fn))]
[else (fn (current-output-port))])
(void))
(define (print-value v)
(bdd-print (lambda (port)
(fprintf port "1 ~A~%#~%" (t-node v)))))
(define (print-nodes ns)
(define cns (vector-length ns))
(define max-var (let loop ([i (sub1 cns)] [ma 0])
(if (< i 0) ma
(loop (sub1 i) (max ma (bdd-node-var (vector-ref ns i)))))))
(define vars (list->vector (if (pair? var-names) var-names
(map (lambda (n) (format "V~A" n)) (range 1 (add1 max-var))))))
(define (var-name id)
(vector-ref vars (sub1 id)))
(define (idx-cnd ix)
(if (integer? ix) (- cns ix) ix))
(define (fold-nodes fn va)
(let loop ([i (sub1 (vector-length ns))] [va va])
(if (< i 0) va
(let ([nd (vector-ref ns i)])
(loop (sub1 i) (fn (idx-cnd i)
(bdd-node-var nd)
(idx-cnd (bdd-node-lo nd))
(idx-cnd (bdd-node-hi nd))
va))))))
(if (> max-var (vector-length vars))
(error 'bdd->tgf "not enough variables for building graph!")
(bdd-print (lambda (port)
(fold-nodes (lambda (id var lo hi va)
(fprintf port "~A ~A~%" id (var-name var)) va)
#f)
(fold-nodes (lambda (id var lo hi va)
(cond [(and (eqv? lo hi) (boolean? lo))
(fprintf port "~A ~A~%" va (t-node lo))
(add1 va)]
[(and (boolean? lo) (boolean? hi))
(fprintf port "~A ~A~%" va (t-node lo))
(fprintf port "~A ~A~%" (add1 va) (t-node hi))
(+ va 2)]
[(boolean? lo)
(fprintf port "~A ~A~%" va (t-node lo))
(add1 va)]
[(boolean? hi)
(fprintf port "~A ~A~%" va (t-node hi))
(add1 va)]
[else va]))
(add1 cns))
(fprintf port "#~%")
(fold-nodes (lambda (id var lo hi va)
(cond [(and (eqv? lo hi) (boolean? lo))
(fprintf port "~A ~A~%" id va)
(fprintf port "~A ~A *~%" id va)
(add1 va)]
[(and (boolean? lo) (boolean? hi))
(fprintf port "~A ~A~%" id va)
(fprintf port "~A ~A *~%" id (add1 va))
(+ va 2)]
[(boolean? lo)
(fprintf port "~A ~A~%" id va)
(fprintf port "~A ~A *~%" id hi)
(add1 va)]
[(boolean? hi)
(fprintf port "~A ~A~%" id lo)
(fprintf port "~A ~A *~%" id va)
(add1 va)]
[else
(fprintf port "~A ~A~%" id lo)
(fprintf port "~A ~A *~%" id hi)
va]))
(add1 cns))))))
(cond [(zdd? dd)
(cases zdd dd
[zdd-value (v)
(print-value v)]
[zdd-nodes (ns)
(print-nodes ns)])]
[(robdd? dd)
(cases robdd dd
[robdd-value (v)
(print-value v)]
[robdd-nodes (ns)
(print-nodes ns)])]
[else
(error 'bdd->tgf "unknown argument type!")]))
;;****************************************************************************
(define (bdd->tree dd)
(define (make-tree ns)
(let loop ([i 0] [ht (hash #f #f #t #t)] [tr #f])
(if (< i (vector-length ns))
(let* ([nd (vector-ref ns i)]
[tr (vector (bdd-node-var nd)
(hash-ref ht (bdd-node-lo nd))
(hash-ref ht (bdd-node-hi nd)))])
(loop (add1 i) (hash-set ht i tr) tr))
tr)))
(cond [(robdd? dd)
(cases robdd dd
[robdd-value (v)
v]
[robdd-nodes (ns)
(make-tree ns)])]
[(zdd? dd)
(cases zdd dd
[zdd-value (v)
v]
[zdd-nodes (ns)
(make-tree ns)])]
[else
(error 'bdd->tree "unknown argument type!")]))