From e1270f81bdc81f5a575b34c2d2c294bdde3e6f4f Mon Sep 17 00:00:00 2001 From: Nathan Binkert Date: Sun, 16 Aug 2009 13:39:58 -0700 Subject: ply: update PLY to version 3.2 --- ext/ply/test/yacc_prec1.py | 68 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 ext/ply/test/yacc_prec1.py (limited to 'ext/ply/test/yacc_prec1.py') diff --git a/ext/ply/test/yacc_prec1.py b/ext/ply/test/yacc_prec1.py new file mode 100644 index 000000000..2ca6afc0b --- /dev/null +++ b/ext/ply/test/yacc_prec1.py @@ -0,0 +1,68 @@ +# ----------------------------------------------------------------------------- +# yacc_prec1.py +# +# Tests case where precedence specifier doesn't match up to terminals +# ----------------------------------------------------------------------------- +import sys + +if ".." not in sys.path: sys.path.insert(0,"..") +import ply.yacc as yacc + +from calclex import tokens + +# Parsing rules +precedence = ( + ('left','+','-'), + ('left','*','/'), + ('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[2] == '/': 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() + + + + -- cgit v1.2.3