diff options
author | Nathan Binkert <nate@binkert.org> | 2009-08-16 13:39:58 -0700 |
---|---|---|
committer | Nathan Binkert <nate@binkert.org> | 2009-08-16 13:39:58 -0700 |
commit | e1270f81bdc81f5a575b34c2d2c294bdde3e6f4f (patch) | |
tree | b54af3469a338609faf04e67603c5264e79d59a5 /ext/ply/test/yacc_uprec2.py | |
parent | bcaf93d182f43bf72d52104bb909324945904120 (diff) | |
download | gem5-e1270f81bdc81f5a575b34c2d2c294bdde3e6f4f.tar.xz |
ply: update PLY to version 3.2
Diffstat (limited to 'ext/ply/test/yacc_uprec2.py')
-rw-r--r-- | ext/ply/test/yacc_uprec2.py | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/ext/ply/test/yacc_uprec2.py b/ext/ply/test/yacc_uprec2.py new file mode 100644 index 000000000..73274bfb6 --- /dev/null +++ b/ext/ply/test/yacc_uprec2.py @@ -0,0 +1,63 @@ +# ----------------------------------------------------------------------------- +# yacc_uprec2.py +# +# A grammar with a bad %prec specifier +# ----------------------------------------------------------------------------- +import sys + +if ".." not in sys.path: sys.path.insert(0,"..") +import ply.yacc as yacc + +from calclex import tokens + +# Parsing rules + +# 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[2] == '/': t[0] = t[1] / t[3] + +def p_expression_uminus(t): + 'expression : MINUS expression %prec' + 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() + + + + |