-
Notifications
You must be signed in to change notification settings - Fork 0
/
Syntax_Validator.py
189 lines (164 loc) · 5.65 KB
/
Syntax_Validator.py
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
'''
S -> IF A | IF A ELSE {B} | IF A ELSEIF A ELSE {B}
A -> (C){S|B}
B -> statements; | statements | statement; | statement
C -> E | F | G
ID -> [a-zA-z]
NUM -> [0-9]
ALNUM -> ID | NUM
E -> ID=ID | ID=NUM
F -> ID==ALNUM | ID!=ALNUM | ID>ALNUM | ID<ALNUM | ID>=ALNUM | ID<=ALNUM
G -> ID++ | ID-- | ++ID | --ID
'''
import ply.lex as lex
import ply.yacc as yacc
tokens = [ 'newline',
'ID',
'LPAREN',
'RPAREN',
'curlyopenbracket',
'curlyclosebracket',
'semicolon',
'EQUALS',
'GREATER_THAN_OR_EQUAL_TO',
'LESSER_THAN_OR_EQUAL_TO',
'GREATER_THAN',
'LESSER_THAN',
'INCREMENT',
'DECREMENT',
'ASSIGN',
'NUMBER',
'NOTEQUALS' ]
reserved = {
'if': 'if',
'elseif': 'elseif',
'else':'else',
'statement':'statement',
'statements':'statements',
}
t_ignore = ' \t'
t_newline = ' \\n'
t_curlyopenbracket = r'\{'
t_curlyclosebracket = r'\}'
t_LPAREN = r'\('
t_RPAREN = r'\)'
t_semicolon = r';'
t_ASSIGN = r'\='
t_EQUALS = r'\=='
t_NOTEQUALS = r'\!='
t_GREATER_THAN_OR_EQUAL_TO = r'\>='
t_LESSER_THAN_OR_EQUAL_TO = r'\<='
t_GREATER_THAN = r'\>'
t_LESSER_THAN = r'\<'
t_INCREMENT = r'\++'
t_DECREMENT = r'\--'
t_NUMBER = r'\d+'
tokens += list(reserved.values())
def t_ID(t):
r'[a-zA-Z_][a-zA-Z_0-9]*'
t.type = reserved.get(t.value, 'ID') # Check for reserved words
return t
def t_if(t):
r'if'
return t
def t_elseif(t):
r'elseif'
return t
def t_else(t):
r'else'
return t
def t_statement(t):
r'statement'
return t
def t_statements(t):
r'statements'
return t
def p_if_loop(p):
'''assign : if expression
| if expression newline else statementsub
| if expression else statementsub
| if expression newline elseif expression newline else statementsub
| if expression newline elseif expression else statementsub
| if expression elseif expression newline else statementsub
| if expression elseif expression else statementsub
| if expression elseif expression
| if expression newline elseif expression'''
print("Syntax is correct.")
def p_if_nested(p):
'''if_nested : if expression
| if expression newline
| if expression newline else statementsub
| if expression newline else statementsub newline
| if expression else statementsub
| if expression else statementsub newline
| if expression newline elseif expression newline else statementsub
| if expression newline elseif expression else statementsub
| if expression elseif expression newline else statementsub
| if expression elseif expression else statementsub
| if expression elseif expression
| if expression newline elseif expression'''
def p_expression(p):
'''expression : conditionsub statementsub'''
def p_conditionsub(p):
'''conditionsub : LPAREN condition RPAREN
| LPAREN assign RPAREN
| newline LPAREN condition RPAREN
'''
def p_statementsub(p):
'''statementsub : curlyopenbracket newline statements semicolon newline curlyclosebracket
| curlyopenbracket newline statements newline curlyclosebracket
| curlyopenbracket statement semicolon curlyclosebracket
| curlyopenbracket statement curlyclosebracket
| newline curlyopenbracket statements semicolon curlyclosebracket
| newline curlyopenbracket statements semicolon newline curlyclosebracket
| newline curlyopenbracket statements curlyclosebracket
| newline curlyopenbracket statements newline curlyclosebracket
| newline curlyopenbracket newline statements semicolon curlyclosebracket
| newline curlyopenbracket newline statements semicolon newline curlyclosebracket
| newline curlyopenbracket newline statements curlyclosebracket
| newline curlyopenbracket newline statements newline curlyclosebracket
| curlyopenbracket newline if_nested newline curlyclosebracket
| curlyopenbracket newline if_nested curlyclosebracket
| curlyopenbracket if_nested curlyclosebracket
| newline curlyopenbracket if_nested curlyclosebracket
| newline curlyopenbracket if_nested newline curlyclosebracket
| newline curlyopenbracket newline if_nested curlyclosebracket
| newline curlyopenbracket newline if_nested newline curlyclosebracket
'''
def p_condition(p):
'''condition : Assign
| Check
| Action'''
def p_condition_part_one(p):
'''Assign : ID ASSIGN ID
| ID ASSIGN NUMBER'''
def p_condition_part_two(p):
'''Check : ID EQUALS Alnum
| ID NOTEQUALS Alnum
| ID GREATER_THAN Alnum
| ID LESSER_THAN Alnum
| ID GREATER_THAN_OR_EQUAL_TO Alnum
| ID LESSER_THAN_OR_EQUAL_TO Alnum'''
def p_condition_part_three(p):
'''Action : ID INCREMENT
| ID DECREMENT
| INCREMENT ID
| DECREMENT ID
| ID ASSIGN ID'''
def p_alnum(p):
'''Alnum : ID
| NUMBER'''
def p_error(p):
print("Syntax error")
quit()
def t_error(p):
print("Token error,")
lex.lex()
yacc.yacc()
data = '''if(!=1){
statements;
}
else{
statements;
}'''
yacc.parse(data)