-
Notifications
You must be signed in to change notification settings - Fork 22
/
shrinks.rb
198 lines (166 loc) · 2.85 KB
/
shrinks.rb
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
# Integer : shrink to zero
class Integer
def shrink
shrunk = if self > 8
self / 2
elsif self > 0
self - 1
elsif self < -8
(self + 1) / 2
elsif self < 0
self + 1
else
0
end
return shrunk
end
def retry?
false
end
def shrinkable?
self != 0
end
end
# String : shrink to ""
class String
def shrink
shrunk = self.dup
if self.size > 0
idx = Random::rand(self.size)
shrunk[idx] = ""
end
return shrunk
end
def retry?
false
end
def shrinkable?
self != ""
end
end
# Array where elements can be shrunk but not removed
class Tuple
def initialize(a)
@array = a
@position = a.size - 1
end
def [](i)
@array[i]
end
def []=(i, value)
@array[i] = value
end
def length
@array.length
end
def size
self.length
end
def to_s
@array.to_s.insert(1, "T ")
end
def inspect
self.to_s
end
def each(&block)
@array.each(&block)
end
def array
return @array
end
def shrink
shrunk = @array.dup
while @position >= 0
e = @array.at(@position)
if e.respond_to?(:shrinkable?) && e.shrinkable?
break
end
@position -= 1
end
if @position >= 0
shrunk[@position] = e.shrink
@position -= 1
end
return Tuple.new(shrunk)
end
def retry?
@position >= 0
end
def shrinkable?
@array.any? {|e| e.respond_to?(:shrinkable?) && e.shrinkable? }
end
end
# Array where the elements that can't be shrunk are removed
class Deflating
def initialize(a)
@array = a
@position = a.size - 1
end
def [](i)
@array[i]
end
def []=(i, value)
@array[i] = value
end
def length
@array.length
end
def size
self.length
end
def to_s
@array.to_s.insert(1, "D ")
end
def inspect
self.to_s
end
def each(&block)
@array.each(&block)
end
def array
return @array
end
def shrink
shrunk = @array.dup
if @position >= 0
e = @array.at(@position)
if e.respond_to?(:shrinkable?) && e.shrinkable?
shrunk[@position] = e.shrink
else
shrunk.delete_at(@position)
end
@position -= 1
end
return Deflating.new(shrunk)
end
def retry?
@position >= 0
end
def shrinkable?
!@array.empty?
end
end
class Hash
def shrink
if self.any?{|_,v| v.respond_to?(:shrinkable?) && v.shrinkable? }
key,_ = self.detect{|_,v| v.respond_to?(:shrinkable?) && v.shrinkable? }
clone = self.dup
clone[key] = clone[key].shrink
return clone
elsif !self.empty?
key = self.keys.first
h2 = self.dup
h2.delete(key)
return h2
else
return self
end
end
def shrinkable?
self.any?{|_,v| v.respond_to?(:shrinkable?) && v.shrinkable? } ||
!self.empty?
end
def retry?
false
end
end