1# ----------------------------------------------------------------------------- 2# yacc_uprec.py 3# 4# A grammar with a bad %prec specifier 5# ----------------------------------------------------------------------------- 6import sys
| 1# ----------------------------------------------------------------------------- 2# yacc_uprec.py 3# 4# A grammar with a bad %prec specifier 5# ----------------------------------------------------------------------------- 6import sys
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7sys.tracebacklimit = 0
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8
| 7
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9sys.path.insert(0,"..")
| 8if ".." not in sys.path: sys.path.insert(0,"..")
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10import ply.yacc as yacc 11 12from calclex import tokens 13 14# Parsing rules 15 16# dictionary of names 17names = { } 18 19def p_statement_assign(t): 20 'statement : NAME EQUALS expression' 21 names[t[1]] = t[3] 22 23def p_statement_expr(t): 24 'statement : expression'
| 9import ply.yacc as yacc 10 11from calclex import tokens 12 13# Parsing rules 14 15# dictionary of names 16names = { } 17 18def p_statement_assign(t): 19 'statement : NAME EQUALS expression' 20 names[t[1]] = t[3] 21 22def p_statement_expr(t): 23 'statement : expression'
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25 print t[1]
| 24 print(t[1])
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26 27def p_expression_binop(t): 28 '''expression : expression PLUS expression 29 | expression MINUS expression 30 | expression TIMES expression 31 | expression DIVIDE expression''' 32 if t[2] == '+' : t[0] = t[1] + t[3] 33 elif t[2] == '-': t[0] = t[1] - t[3] 34 elif t[2] == '*': t[0] = t[1] * t[3]
| 25 26def p_expression_binop(t): 27 '''expression : expression PLUS expression 28 | expression MINUS expression 29 | expression TIMES expression 30 | expression DIVIDE expression''' 31 if t[2] == '+' : t[0] = t[1] + t[3] 32 elif t[2] == '-': t[0] = t[1] - t[3] 33 elif t[2] == '*': t[0] = t[1] * t[3]
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35 elif t[3] == '/': t[0] = t[1] / t[3]
| 34 elif t[2] == '/': t[0] = t[1] / t[3]
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36 37def p_expression_uminus(t): 38 'expression : MINUS expression %prec UMINUS' 39 t[0] = -t[2] 40 41def p_expression_group(t): 42 'expression : LPAREN expression RPAREN' 43 t[0] = t[2] 44 45def p_expression_number(t): 46 'expression : NUMBER' 47 t[0] = t[1] 48 49def p_expression_name(t): 50 'expression : NAME' 51 try: 52 t[0] = names[t[1]] 53 except LookupError:
| 35 36def p_expression_uminus(t): 37 'expression : MINUS expression %prec UMINUS' 38 t[0] = -t[2] 39 40def p_expression_group(t): 41 'expression : LPAREN expression RPAREN' 42 t[0] = t[2] 43 44def p_expression_number(t): 45 'expression : NUMBER' 46 t[0] = t[1] 47 48def p_expression_name(t): 49 'expression : NAME' 50 try: 51 t[0] = names[t[1]] 52 except LookupError:
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54 print "Undefined name '%s'" % t[1]
| 53 print("Undefined name '%s'" % t[1])
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55 t[0] = 0 56 57def p_error(t):
| 54 t[0] = 0 55 56def p_error(t):
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58 print "Syntax error at '%s'" % t.value
| 57 print("Syntax error at '%s'" % t.value)
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59 60yacc.yacc() 61 62 63 64
| 58 59yacc.yacc() 60 61 62 63
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