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
193
194
195
196
197
198
199
200
|
; ACL2 String Library
; Copyright (C) 2009-2013 Centaur Technology
;
; Contact:
; Centaur Technology Formal Verification Group
; 7600-C N. Capital of Texas Highway, Suite 300, Austin, TX 78731, USA.
; http://www.centtech.com/
;
; License: (An MIT/X11-style license)
;
; Permission is hereby granted, free of charge, to any person obtaining a
; copy of this software and associated documentation files (the "Software"),
; to deal in the Software without restriction, including without limitation
; the rights to use, copy, modify, merge, publish, distribute, sublicense,
; and/or sell copies of the Software, and to permit persons to whom the
; Software is furnished to do so, subject to the following conditions:
;
; The above copyright notice and this permission notice shall be included in
; all copies or substantial portions of the Software.
;
; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
; DEALINGS IN THE SOFTWARE.
;
; Original author: Jared Davis <jared@centtech.com>
(in-package "STR")
(include-book "cat")
(include-book "strprefixp")
(local (include-book "arithmetic"))
(defsection strsubst-aux
:parents (strsubst)
:short "Fast implementation of @(see strsubst)."
(defund strsubst-aux (old new x n xl oldl acc)
(declare (type string old new x)
(type (integer 0 *) n xl oldl)
(xargs :guard (and (stringp old)
(stringp new)
(stringp x)
(natp n)
(natp xl)
(posp oldl)
(= oldl (length old))
(= xl (length x)))
:measure (nfix (- (nfix xl) (nfix n)))))
(cond ((mbe :logic (zp oldl)
:exec nil)
acc)
((mbe :logic (zp (- (nfix xl) (nfix n)))
:exec (>= n xl))
acc)
((strprefixp-impl old x 0 n oldl xl)
(let ((acc (revappend-chars new acc)))
(strsubst-aux old new x
(the (integer 0 *)
(+ oldl (the (integer 0 *) (lnfix n))))
xl oldl acc)))
(t
(let ((acc (cons (char x n) acc)))
(strsubst-aux old new x
(the (integer 0 *)
(+ 1 (the (integer 0 *) (lnfix n))))
xl oldl acc)))))
(local (in-theory (enable strsubst-aux)))
(defthm character-listp-of-strsubst-aux
(implies (and (stringp old)
(stringp new)
(stringp x)
(natp n)
(posp oldl)
(= oldl (length old))
(= xl (length x))
(character-listp acc))
(character-listp (strsubst-aux old new x n xl oldl acc)))))
(defsection strsubst
:parents (substitution substitute)
:short "Replace substrings throughout a string."
:long "<p>@(call strsubst) replaces each occurrence of @('old') with @('new')
throughout @('x'). Each argument is a string, and a new string is returned.
The replacement is done globally and non-recursively.</p>
<p>Examples:</p>
@({
(strsubst \"World\" \"Star\" \"Hello, World!\")
-->
\"Hello, Star!\"
(strsubst \"oo\" \"aa\" \"xoooyoo\")
-->
\"xaaoyaa\"
})
<p>ACL2 has a built in @(see substitute) function, but it only works on
individual characters, whereas @('strsubst') works on substrings.</p>"
;; BOZO probably worthwhile to check if old occurs, and if not don't bother to
;; do any coercion, etc.
(defund strsubst (old new x)
(declare (xargs :guard (and (stringp old)
(stringp new)
(stringp x))))
(let ((oldl (mbe :logic (len (explode old))
:exec (length old)))
(xl (mbe :logic (len (explode x))
:exec (length x))))
(if (zp oldl)
(mbe :logic (str-fix x)
:exec x)
(rchars-to-string (strsubst-aux old new x 0 xl oldl nil)))))
(local (in-theory (enable strsubst)))
(defthm stringp-of-strsubst
(stringp (strsubst old new x))
:rule-classes :type-prescription))
(defsection strsubst-list
:parents (substitution)
:short "Carry out a @(see strsubst) replacement throughout a list of strings."
:long "<p>@(call strsubst-list) replaces every occurrence of @('old') with
@('new') throughout @('x'). Here, @('old') and @('new') are strings, but
@('x') is a list of strings. A new list of strings is returned.</p>
<p>Example:</p>
@({
(strsubst-list \"Sun\"
\"Moon\"
'(\"Sun Roof\" \"Hello Sun\" \"Sunny Sunshades\"))
-->
(\"Moon Roof\" \"Hello Moon\" \"Moonny Moonshades\")
})"
;; BOZO consider using defprojection
(defund strsubst-list (old new x)
(declare (xargs :guard (and (stringp old)
(stringp new)
(string-listp x))))
(if (atom x)
nil
(cons (strsubst old new (car x))
(strsubst-list old new (cdr x)))))
(local (in-theory (enable strsubst-list)))
(defthm strsubst-list-when-atom
(implies (atom x)
(equal (strsubst-list old new x)
nil)))
(defthm strsubst-list-of-cons
(equal (strsubst-list old new (cons a x))
(cons (strsubst old new a)
(strsubst-list old new x))))
(defthm string-listp-of-strsubst-list
(string-listp (strsubst-list old new x)))
(local (defthm l0
(equal (strsubst-list old new (list-fix x))
(strsubst-list old new x))))
(defcong list-equiv equal (strsubst-list old new x) 3
:hints(("Goal"
:in-theory (disable l0)
:use ((:instance l0 (x x))
(:instance l0 (x x-equiv))))))
(defthm strsubst-list-of-append
(equal (strsubst-list old new (append x y))
(append (strsubst-list old new x)
(strsubst-list old new y))))
(defthm strsubst-list-of-revappend
(equal (strsubst-list old new (revappend x y))
(revappend (strsubst-list old new x)
(strsubst-list old new y))))
(defthm strsubst-list-of-rev
(equal (strsubst-list old new (rev x))
(rev (strsubst-list old new x)))))
|
