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author | David Beazley <dave@dabeaz.com> | 2008-05-29 14:00:14 +0000 |
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committer | David Beazley <dave@dabeaz.com> | 2008-05-29 14:00:14 +0000 |
commit | 3d91085e98cd5d2ddd3822793ab33bbad8287f5c (patch) | |
tree | 81d1988b5dec2f2b51c465527a3fe103847808b0 /test/yacc_badprec3.py | |
parent | 912137883ba0ec6e0f0390c9664a7918ee529c14 (diff) | |
download | ply-3d91085e98cd5d2ddd3822793ab33bbad8287f5c.tar.gz |
Revamped testing framework
Diffstat (limited to 'test/yacc_badprec3.py')
-rw-r--r-- | test/yacc_badprec3.py | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/test/yacc_badprec3.py b/test/yacc_badprec3.py new file mode 100644 index 0000000..5998dd0 --- /dev/null +++ b/test/yacc_badprec3.py @@ -0,0 +1,68 @@ +# ----------------------------------------------------------------------------- +# yacc_badprec3.py +# +# Bad precedence +# ----------------------------------------------------------------------------- +import sys + +if ".." not in sys.path: sys.path.insert(0,"..") +import ply.yacc as yacc + +from calclex import tokens + +# Parsing rules +precedence = ( + ('left','PLUS','MINUS'), + ('left','TIMES','DIVIDE','MINUS'), + ('right','UMINUS'), + ) + +# dictionary of names +names = { } + +def p_statement_assign(t): + 'statement : NAME EQUALS expression' + names[t[1]] = t[3] + +def p_statement_expr(t): + 'statement : expression' + print t[1] + +def p_expression_binop(t): + '''expression : expression PLUS expression + | expression MINUS expression + | expression TIMES expression + | expression DIVIDE expression''' + if t[2] == '+' : t[0] = t[1] + t[3] + elif t[2] == '-': t[0] = t[1] - t[3] + elif t[2] == '*': t[0] = t[1] * t[3] + elif t[3] == '/': t[0] = t[1] / t[3] + +def p_expression_uminus(t): + 'expression : MINUS expression %prec UMINUS' + t[0] = -t[2] + +def p_expression_group(t): + 'expression : LPAREN expression RPAREN' + t[0] = t[2] + +def p_expression_number(t): + 'expression : NUMBER' + t[0] = t[1] + +def p_expression_name(t): + 'expression : NAME' + try: + t[0] = names[t[1]] + except LookupError: + print "Undefined name '%s'" % t[1] + t[0] = 0 + +def p_error(t): + print "Syntax error at '%s'" % t.value + +yacc.yacc() + + + + |