def setUp(self):
self.arith = grammar.Grammar('S', ('+', '*', '(', ')', 'id'))
self.result = None
def get_result(v):
self.result = v
return v
def add(x, y):
t = x + y
return t
def mul(x, y):
t = x * y
return t
self.arith.add_rule('S', ['E', get_result])
self.arith.add_rule('E', ['E', '+', 'T', add])
self.arith.add_rule('E', ['T', lambda v: v])
self.arith.add_rule('T', ['T', '*', 'F', mul])
self.arith.add_rule('T', ['F', lambda v: v])
self.arith.add_rule('F', ['(', 'E', ')', lambda v: v])
self.arith.add_rule('F', ['id', lambda v: v])
self.action_table, self.goto_table, self.start_state = build_parsing_table(
self.arith, LR0(self.arith.START, 0, 0))
self.driver = Driver(self.action_table, self.goto_table,
self.start_state)
def setUp(self):
self.lrvalue = grammar.Grammar(None, ('=', '*', ';', 'id', 'num'))
self.symbol_table = dict()
self.last_value = None
def set_var(lv, rv):
self.symbol_table[lv] = rv;
return self.symbol_table[lv]
def get_var(rv):
if rv in self.symbol_table:
return self.symbol_table[rv]
raise KeyError(rv)
def grab_last_value(v):
self.last_value = v if isinstance(v, int) else self.symbol_table[v]
return v
self.lrvalue.augment('S')
self.lrvalue.add_rule('S', ['E', ';', 'S', lambda e, s: s])
self.lrvalue.add_rule('S', ['E', ';', lambda v: v])
self.lrvalue.add_rule('E', ['L', '=', 'R', set_var])
self.lrvalue.add_rule('E', ['R', grab_last_value])
self.lrvalue.add_rule('L', ['*', 'R', get_var])
self.lrvalue.add_rule('L', ['id', lambda v: v])
self.lrvalue.add_rule('R', ['L', lambda v: v])
self.lrvalue.add_rule('R', ['num', lambda v: v])
self.action_table, self.goto_table, self.start_state = build_parsing_table_lalr(self.lrvalue, LR0(self.lrvalue.START, 0, 0), False)
self.driver = Driver(self.action_table, self.goto_table, self.start_state)
def setUp(self):
self.arith = grammar.Grammar(
'S', ('+', '*', '(', ')', 'id', 'var', '=', 'let'))
self.symbol_table = [dict()]
self.result = None
def get_result(x):
self.result = x
return x
def add(x, y):
t = x + y
return t
def mul(x, y):
t = x * y
return t
def set_var(lv, rv):
self.symbol_table[-1][lv] = rv
return rv
def get_var(rv):
for table in reversed(self.symbol_table):
if rv in table:
return table[rv]
raise KeyError(rv)
def push():
self.symbol_table.append(dict())
def pop(*others):
self.symbol_table.pop()
self.arith.add_rule('S', ['E', get_result])
self.arith.add_rule('E', ['E', '+', 'T', add])
self.arith.add_rule('E', ['T', lambda v: v])
self.arith.add_rule('T', ['T', '*', 'F', mul])
self.arith.add_rule('T', ['F', lambda v: v])
self.arith.add_rule('F', ['(', 'E', ')', lambda v: v])
self.arith.add_rule('F', ['id', lambda v: v])
self.arith.add_rule('F', ['var', '=', 'E', set_var])
self.arith.add_rule('F', ['var', get_var])
self.arith.add_rule('F',
['let', push, '(', 'E', ')', pop, lambda v: v])
self.action_table, self.goto_table, self.start_state = build_parsing_table(
self.arith, LR0(self.arith.START, 0, 0))
self.driver = Driver(self.action_table, self.goto_table,
self.start_state)
def setUp(self):
self.arith = grammar.Grammar('S', ('(', ')', 'id', 'let'))
self.symbol_table = [dict()]
def push(*args):
pass
def pop(*args):
pass
self.arith.add_rule('S', ['E'])
self.arith.add_rule('E', ['id'])
self.arith.add_rule(
'E', ['let', push, '(', 'E', ')', pop, lambda *args: args])
self.action_table, self.goto_table, self.start_state = build_parsing_table(
self.arith, LR0(self.arith.START, 0, 0), disable_mapping=True)
self.driver = Driver(self.action_table, dict(self.goto_table),
self.start_state)
def probe(*args):
print "--", len(args), "-", " ".join(map(str, args))
def prompt(*args):
print ">>> ",
grammar = from_string(rpcalc_grammar,
'input',
print_result=print_result,
probe=probe,
prompt=prompt,
up=lambda x: x,
add=lambda x, y: x + y,
sub=lambda x, y: x - y,
mul=lambda x, y: x * y,
div=lambda x, y: x / y,
mod=lambda x, y: x % y,
neg=lambda x: -x)
states, gotos, first = build_parsing_table(grammar, LR0(grammar.START, 0, 0))
driver = Driver(states, gotos, first)
print "Reverse polish calculator. Write expressions like "
print " >>> 2 + 3 (result in 2 + 3 = 5) or "
print " >>> 2 + 4 * 5 (result in 2 + (4 * 5) = 22)"
print
prompt()
driver.parse(CalcLexer(sys.stdin))
def setUp(self):
syn = syntax.Syntax('input')
self.result = []
syn.terminal('NL', None)
syn.terminal('NUM', None)
syn.terminal('+', None)
syn.terminal('-', None)
syn.repeat(('line', ), 'input')
syn.choice((('NL', ), ('expr', 'NL', lambda x: self.result.append(x))),
'line')
syn.choice((('NUM', ), ('expr', 'expr', '+', lambda x, y: x + y),
('expr', 'expr', '-', lambda x, y: x - y)), 'expr')
self.grammar = syn.as_grammar()
self.start_item = LR0(self.grammar.START, 0, 0)
self.action_table, self.goto_table, self.start_state = build_parsing_table(
self.grammar, self.start_item, disable_mapping=True)
self.driver = Driver(self.action_table, self.goto_table,
self.start_state)
self.kernel_states = [
frozenset([
LR0(self.grammar.START, 0, 0),
]),
frozenset([
LR0(self.grammar.START, 0, 1),
]),
frozenset([
LR0('input', 0, 1),
LR0('input', 1, 1),
]),
frozenset([
LR0('line', 0, 1),
]),
frozenset([
LR0('line', 1, 1),
LR0('expr', 1, 1),
LR0('expr', 2, 1),
]),
frozenset([
LR0('expr', 0, 1),
]),
frozenset([
LR0('input', 0, 2),
]),
frozenset([
LR0('line', 1, 2),
]),
frozenset([
LR0('expr', 1, 1),
LR0('expr', 1, 2),
LR0('expr', 2, 1),
LR0('expr', 2, 2),
]),
frozenset([
LR0('expr', 1, 3),
]),
frozenset([
LR0('expr', 2, 3),
])
]
