7267
|
1 # lex_state_try.py
|
|
2 #
|
|
3 # Declaration of a state for which no rules are defined
|
|
4
|
|
5 import sys
|
|
6 if ".." not in sys.path: sys.path.insert(0,"..")
|
|
7
|
|
8 import ply.lex as lex
|
|
9
|
|
10 tokens = [
|
|
11 "PLUS",
|
|
12 "MINUS",
|
|
13 "NUMBER",
|
|
14 ]
|
|
15
|
|
16 states = (('comment', 'exclusive'),)
|
|
17
|
|
18 t_PLUS = r'\+'
|
|
19 t_MINUS = r'-'
|
|
20 t_NUMBER = r'\d+'
|
|
21
|
|
22 t_ignore = " \t"
|
|
23
|
|
24 # Comments
|
|
25 def t_comment(t):
|
|
26 r'/\*'
|
|
27 t.lexer.begin('comment')
|
|
28 print("Entering comment state")
|
|
29
|
|
30 def t_comment_body_part(t):
|
|
31 r'(.|\n)*\*/'
|
|
32 print("comment body %s" % t)
|
|
33 t.lexer.begin('INITIAL')
|
|
34
|
|
35 def t_error(t):
|
|
36 pass
|
|
37
|
|
38 t_comment_error = t_error
|
|
39 t_comment_ignore = t_ignore
|
|
40
|
|
41 lex.lex()
|
|
42
|
|
43 data = "3 + 4 /* This is a comment */ + 10"
|
|
44
|
|
45 lex.runmain(data=data)
|