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
|
module JGrep
class Scanner
attr_accessor :arguments, :token_index
def initialize(arguments)
@token_index = 0
@arguments = arguments
end
# Scans the input string and identifies single language tokens
def get_token
return nil if @token_index >= @arguments.size
begin
case chr(@arguments[@token_index])
when "["
return "statement", gen_substatement
when "]"
return "]"
when "("
return "(", "("
when ")"
return ")", ")"
when "n"
if (chr(@arguments[@token_index + 1]) == "o") && (chr(@arguments[@token_index + 2]) == "t") && ((chr(@arguments[@token_index + 3]) == " ") || (chr(@arguments[@token_index + 3]) == "("))
@token_index += 2
return "not", "not"
else
gen_statement
end
when "!"
return "not", "not"
when "a"
if (chr(@arguments[@token_index + 1]) == "n") && (chr(@arguments[@token_index + 2]) == "d") && ((chr(@arguments[@token_index + 3]) == " ") || (chr(@arguments[@token_index + 3]) == "("))
@token_index += 2
return "and", "and"
else
gen_statement
end
when "&"
if chr(@arguments[@token_index + 1]) == "&"
@token_index += 1
return "and", "and"
else
gen_statement
end
when "o"
if (chr(@arguments[@token_index + 1]) == "r") && ((chr(@arguments[@token_index + 2]) == " ") || (chr(@arguments[@token_index + 2]) == "("))
@token_index += 1
return "or", "or"
else
gen_statement
end
when "|"
if chr(@arguments[@token_index + 1]) == "|"
@token_index += 1
return "or", "or"
else
gen_statement
end
when "+"
value = ""
i = @token_index + 1
begin
value += chr(@arguments[i])
i += 1
end until (i >= @arguments.size) || (chr(@arguments[i]) =~ /\s|\)/)
@token_index = i - 1
return "+", value
when "-"
value = ""
i = @token_index + 1
begin
value += chr(@arguments[i])
i += 1
end until (i >= @arguments.size) || (chr(@arguments[i]) =~ /\s|\)/)
@token_index = i - 1
return "-", value
when " "
return " ", " "
else
gen_statement
end
end
rescue NoMethodError
raise "Error. Expression cannot be parsed."
end
private
def gen_substatement
@token_index += 1
returnval = []
while (val = get_token) != "]"
@token_index += 1
returnval << val unless val[0] == " "
end
returnval
end
def gen_statement
current_token_value = ""
j = @token_index
begin
if chr(@arguments[j]) == "/"
begin
current_token_value << chr(@arguments[j])
j += 1
if chr(@arguments[j]) == "/"
current_token_value << "/"
break
end
end until (j >= @arguments.size) || (chr(@arguments[j]) =~ /\//)
else
begin
current_token_value << chr(@arguments[j])
j += 1
if chr(@arguments[j]) =~ /'|"/
begin
current_token_value << chr(@arguments[j])
j += 1
end until (j >= @arguments.size) || (chr(@arguments[j]) =~ /'|"/)
end
end until (j >= @arguments.size) || (chr(@arguments[j]) =~ /\s|\)|\]/ && chr(@arguments[j - 1]) != '\\')
end
rescue
raise "Invalid token found - '#{current_token_value}'"
end
if current_token_value =~ /^(and|or|not|!)$/
raise "Class name cannot be 'and', 'or', 'not'. Found '#{current_token_value}'"
end
@token_index += current_token_value.size - 1
["statement", current_token_value]
end
# Compatibility with 1.8.7, which returns a Fixnum from String#[]
def chr(character)
character.chr unless character.nil?
end
end
end
|
