1 # -----------------------------------------------------------------------------
4 # Bad p_error() function
5 # -----------------------------------------------------------------------------
9 sys
.path
.insert(0,"..")
10 import ply
.yacc
as yacc
12 from calclex
import tokens
16 ('left','PLUS','MINUS'),
17 ('left','TIMES','DIVIDE'),
24 def p_statement_assign(t
):
25 'statement : NAME EQUALS expression'
28 def p_statement_expr(t
):
29 'statement : expression'
32 def p_expression_binop(t
):
33 '''expression : expression PLUS expression
34 | expression MINUS expression
35 | expression TIMES expression
36 | expression DIVIDE expression'''
37 if t
[2] == '+' : t
[0] = t
[1] + t
[3]
38 elif t
[2] == '-': t
[0] = t
[1] - t
[3]
39 elif t
[2] == '*': t
[0] = t
[1] * t
[3]
40 elif t
[3] == '/': t
[0] = t
[1] / t
[3]
42 def p_expression_uminus(t
):
43 'expression : MINUS expression %prec UMINUS'
46 def p_expression_group(t
):
47 'expression : LPAREN expression RPAREN'
50 def p_expression_number(t
):
54 def p_expression_name(t
):
59 print "Undefined name '%s'" % t
[1]