3 from ply import lex, yacc
7 tokens = ('NAME', 'AND_OP', 'OR_OP', 'NOT_OP', 'SP1')
9 t_NAME = '([a-z][a-z0-9_]*)|AND|OR|NOT'
20 """Avoid warnings on stderr"""
24 def p_expression_name(p):
25 """expression : NAME"""
28 def p_expression_and_and(p):
29 """expression : expression SP0 AND_OP AND_OP SP0 expression"""
30 p[0] = ('AND', p[1], p[6])
32 def p_expression_and(p):
33 """expression : expression SP0 AND_OP SP0 expression"""
34 p[0] = ('AND', p[1], p[5])
36 def p_expression_op_word(p):
37 """expression : l_expression op_word r_expression"""
38 if p[2] in ('AND', 'and'):
39 p[0] = ('AND', p[1], p[3])
40 elif p[2] in ('OR', 'or'):
41 p[0] = ('OR', p[1], p[3])
43 def p_expression_or_or(p):
44 """expression : expression SP0 OR_OP OR_OP SP0 expression"""
45 p[0] = ('OR', p[1], p[6])
47 def p_expression_or(p):
48 """expression : expression SP0 OR_OP SP0 expression"""
49 p[0] = ('OR', p[1], p[5])
51 def p_expression_not(p):
52 """expression : NOT_OP SP0 expression"""
55 def p_expression_in_parens(p):
56 """expression : expression_parens"""
59 def p_l_expression(p):
60 """l_expression : expression_parens
70 def p_r_expression(p):
71 """r_expression : expression_parens
81 def p_expression_parens(p):
82 """expression_parens : '(' SP0 expression SP0 ')'"""
83 p[0] = ('PARENS', p[3])
87 if p[1] in ('AND', 'and', 'OR', 'or'):
101 """Avoid warnings on stderr"""