gem5/ext/ply/example/optcalc/calc.py
Nathan Binkert 44ebb8d3e2 Update to ply 2.3
ext/ply/ply/lex.py:
ext/ply/ply/yacc.py:
ext/ply/CHANGES:
ext/ply/README:
ext/ply/TODO:
ext/ply/doc/ply.html:
ext/ply/example/ansic/clex.py:
ext/ply/example/ansic/cparse.py:
ext/ply/example/calc/calc.py:
ext/ply/example/hedit/hedit.py:
ext/ply/example/optcalc/calc.py:
ext/ply/test/README:
ext/ply/test/calclex.py:
ext/ply/test/lex_doc1.exp:
ext/ply/test/lex_doc1.py:
ext/ply/test/lex_dup1.exp:
ext/ply/test/lex_dup1.py:
ext/ply/test/lex_dup2.exp:
ext/ply/test/lex_dup2.py:
ext/ply/test/lex_dup3.exp:
ext/ply/test/lex_dup3.py:
ext/ply/test/lex_empty.py:
ext/ply/test/lex_error1.py:
ext/ply/test/lex_error2.py:
ext/ply/test/lex_error3.exp:
ext/ply/test/lex_error3.py:
ext/ply/test/lex_error4.exp:
ext/ply/test/lex_error4.py:
ext/ply/test/lex_hedit.exp:
ext/ply/test/lex_hedit.py:
ext/ply/test/lex_ignore.exp:
ext/ply/test/lex_ignore.py:
ext/ply/test/lex_re1.exp:
ext/ply/test/lex_re1.py:
ext/ply/test/lex_rule1.py:
ext/ply/test/lex_token1.py:
ext/ply/test/lex_token2.py:
ext/ply/test/lex_token3.py:
ext/ply/test/lex_token4.py:
ext/ply/test/lex_token5.exp:
ext/ply/test/lex_token5.py:
ext/ply/test/yacc_badargs.exp:
ext/ply/test/yacc_badargs.py:
ext/ply/test/yacc_badprec.exp:
ext/ply/test/yacc_badprec.py:
ext/ply/test/yacc_badprec2.exp:
ext/ply/test/yacc_badprec2.py:
ext/ply/test/yacc_badrule.exp:
ext/ply/test/yacc_badrule.py:
ext/ply/test/yacc_badtok.exp:
ext/ply/test/yacc_badtok.py:
ext/ply/test/yacc_dup.exp:
ext/ply/test/yacc_dup.py:
ext/ply/test/yacc_error1.exp:
ext/ply/test/yacc_error1.py:
ext/ply/test/yacc_error2.exp:
ext/ply/test/yacc_error2.py:
ext/ply/test/yacc_error3.exp:
ext/ply/test/yacc_error3.py:
ext/ply/test/yacc_inf.exp:
ext/ply/test/yacc_inf.py:
ext/ply/test/yacc_missing1.exp:
ext/ply/test/yacc_missing1.py:
ext/ply/test/yacc_nodoc.exp:
ext/ply/test/yacc_nodoc.py:
ext/ply/test/yacc_noerror.exp:
ext/ply/test/yacc_noerror.py:
ext/ply/test/yacc_nop.exp:
ext/ply/test/yacc_nop.py:
ext/ply/test/yacc_notfunc.exp:
ext/ply/test/yacc_notfunc.py:
ext/ply/test/yacc_notok.exp:
ext/ply/test/yacc_notok.py:
ext/ply/test/yacc_rr.exp:
ext/ply/test/yacc_rr.py:
ext/ply/test/yacc_simple.exp:
ext/ply/test/yacc_simple.py:
ext/ply/test/yacc_sr.exp:
ext/ply/test/yacc_sr.py:
ext/ply/test/yacc_term1.exp:
ext/ply/test/yacc_term1.py:
ext/ply/test/yacc_unused.exp:
ext/ply/test/yacc_unused.py:
ext/ply/test/yacc_uprec.exp:
ext/ply/test/yacc_uprec.py:
    Import patch ply.diff
src/arch/isa_parser.py:
    everything is now within the ply package

--HG--
rename : ext/ply/lex.py => ext/ply/ply/lex.py
rename : ext/ply/yacc.py => ext/ply/ply/yacc.py
extra : convert_revision : fca8deabd5c095bdeabd52a1f236ae1404ef106e
2007-05-24 21:54:51 -07:00

113 lines
2.3 KiB
Python

# -----------------------------------------------------------------------------
# calc.py
#
# A simple calculator with variables. This is from O'Reilly's
# "Lex and Yacc", p. 63.
# -----------------------------------------------------------------------------
import sys
sys.path.insert(0,"../..")
tokens = (
'NAME','NUMBER',
'PLUS','MINUS','TIMES','DIVIDE','EQUALS',
'LPAREN','RPAREN',
)
# Tokens
t_PLUS = r'\+'
t_MINUS = r'-'
t_TIMES = r'\*'
t_DIVIDE = r'/'
t_EQUALS = r'='
t_LPAREN = r'\('
t_RPAREN = r'\)'
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
def t_NUMBER(t):
r'\d+'
try:
t.value = int(t.value)
except ValueError:
print "Integer value too large", t.value
t.value = 0
return t
t_ignore = " \t"
def t_newline(t):
r'\n+'
t.lexer.lineno += t.value.count("\n")
def t_error(t):
print "Illegal character '%s'" % t.value[0]
t.lexer.skip(1)
# Build the lexer
import ply.lex as lex
lex.lex(optimize=1)
# Parsing rules
precedence = (
('left','PLUS','MINUS'),
('left','TIMES','DIVIDE'),
('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]
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
import ply.yacc as yacc
yacc.yacc(optimize=1)
while 1:
try:
s = raw_input('calc > ')
except EOFError:
break
yacc.parse(s)