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
|
# -*- ruby encoding: utf-8 -*-
# Represents a simplistic (non-contextual) change. Represents the removal or
# addition of an element from either the old or the new sequenced
# enumerable.
class Diff::LCS::Change
IntClass = 1.class # Fixnum is deprecated in Ruby 2.4
# The only actions valid for changes are '+' (add), '-' (delete), '='
# (no change), '!' (changed), '<' (tail changes from first sequence), or
# '>' (tail changes from second sequence). The last two ('<>') are only
# found with Diff::LCS::diff and Diff::LCS::sdiff.
VALID_ACTIONS = %W(+ - = ! > <)
def self.valid_action?(action)
VALID_ACTIONS.include? action
end
# Returns the action this Change represents.
attr_reader :action
# Returns the position of the Change.
attr_reader :position
# Returns the sequence element of the Change.
attr_reader :element
def initialize(*args)
@action, @position, @element = *args
unless Diff::LCS::Change.valid_action?(@action)
raise "Invalid Change Action '#{@action}'"
end
raise "Invalid Position Type" unless @position.kind_of? IntClass
end
def inspect
to_a.inspect
end
def to_a
[ @action, @position, @element ]
end
def self.from_a(arr)
arr = arr.flatten(1)
case arr.size
when 5
Diff::LCS::ContextChange.new(*(arr[0...5]))
when 3
Diff::LCS::Change.new(*(arr[0...3]))
else
raise "Invalid change array format provided."
end
end
include Comparable
def ==(other)
(self.class == other.class) and
(self.action == other.action) and
(self.position == other.position) and
(self.element == other.element)
end
def <=>(other)
r = self.action <=> other.action
r = self.position <=> other.position if r.zero?
r = self.element <=> other.element if r.zero?
r
end
def adding?
@action == '+'
end
def deleting?
@action == '-'
end
def unchanged?
@action == '='
end
def changed?
@action == '!'
end
def finished_a?
@action == '>'
end
def finished_b?
@action == '<'
end
end
# Represents a contextual change. Contains the position and values of the
# elements in the old and the new sequenced enumerables as well as the action
# taken.
class Diff::LCS::ContextChange < Diff::LCS::Change
# We don't need these two values.
undef :position
undef :element
# Returns the old position being changed.
attr_reader :old_position
# Returns the new position being changed.
attr_reader :new_position
# Returns the old element being changed.
attr_reader :old_element
# Returns the new element being changed.
attr_reader :new_element
def initialize(*args)
@action, @old_position, @old_element, @new_position, @new_element = *args
unless Diff::LCS::Change.valid_action?(@action)
raise "Invalid Change Action '#{@action}'"
end
unless @old_position.nil? or @old_position.kind_of? IntClass
raise "Invalid (Old) Position Type"
end
unless @new_position.nil? or @new_position.kind_of? IntClass
raise "Invalid (New) Position Type"
end
end
def to_a
[ @action,
[ @old_position, @old_element ],
[ @new_position, @new_element ]
]
end
def inspect(*args)
to_a.inspect
end
def self.from_a(arr)
Diff::LCS::Change.from_a(arr)
end
# Simplifies a context change for use in some diff callbacks. '<' actions
# are converted to '-' and '>' actions are converted to '+'.
def self.simplify(event)
ea = event.to_a
case ea[0]
when '-'
ea[2][1] = nil
when '<'
ea[0] = '-'
ea[2][1] = nil
when '+'
ea[1][1] = nil
when '>'
ea[0] = '+'
ea[1][1] = nil
end
Diff::LCS::ContextChange.from_a(ea)
end
def ==(other)
(self.class == other.class) and
(@action == other.action) and
(@old_position == other.old_position) and
(@new_position == other.new_position) and
(@old_element == other.old_element) and
(@new_element == other.new_element)
end
def <=>(other)
r = @action <=> other.action
r = @old_position <=> other.old_position if r.zero?
r = @new_position <=> other.new_position if r.zero?
r = @old_element <=> other.old_element if r.zero?
r = @new_element <=> other.new_element if r.zero?
r
end
end
|