def register(cls, symbol, **kwargs):
"""
Register/update a token class in the symbol table.
:param symbol: The identifier symbol for a new class or an existent token class.
:param kwargs: Optional attributes/methods for the token class.
:return: A token class.
"""
try:
try:
if ' ' in symbol:
raise ValueError("%r: a symbol can't contain whitespaces" % symbol)
except TypeError:
assert isinstance(symbol, type) and issubclass(symbol, Token), \
"A %r subclass requested, not %r." % (Token, symbol)
symbol, token_class = symbol.symbol, symbol
assert symbol in cls.symbol_table and cls.symbol_table[symbol] is token_class, \
"Token class %r is not registered." % token_class
else:
token_class = cls.symbol_table[symbol]
except KeyError:
# Register a new symbol and create a new custom class. The new class
# name is registered at parser class's module level.
if symbol not in cls.SYMBOLS:
raise NameError('%r is not a symbol of the parser %r.' % (symbol, cls))
kwargs['symbol'] = symbol
label = kwargs.get('label', 'symbol')
if isinstance(label, tuple):
label = kwargs['label'] = MultiLabel(*label)
token_class_name = "_{}{}".format(
symbol_to_classname(symbol), str(label).title().replace(' ', '')
)
token_class_bases = kwargs.get('bases', (cls.token_base_class,))
kwargs.update({
'__module__': cls.__module__,
'__qualname__': token_class_name,
'__return__': None
})
token_class = ABCMeta(token_class_name, token_class_bases, kwargs)
cls.symbol_table[symbol] = token_class
MutableSequence.register(token_class)
setattr(sys.modules[cls.__module__], token_class_name, token_class)
else:
for key, value in kwargs.items():
if key == 'lbp' and value > token_class.lbp:
token_class.lbp = value
elif key == 'rbp' and value > token_class.rbp:
token_class.rbp = value
elif callable(value):
setattr(token_class, key, value)
return token_class
def register(cls, symbol, **kwargs):
"""
Register/update a token class in the symbol table.
:param symbol: The identifier symbol for a new class or an existent token class.
:param kwargs: Optional attributes/methods for the token class.
:return: A token class.
"""
def symbol_escape(s):
s = re.escape(s)
s.replace(r'\ ', r'\s+')
if s.isalpha():
s = r'\b%s\b(?![\-\.])' % s
elif s[-2:] == r'\(':
s = r'%s\s*%s' % (s[:-2], s[-2:])
elif s[-4:] == r'\:\:':
s = r'%s\s*%s' % (s[:-4], s[-4:])
return s
try:
try:
if ' ' in symbol:
raise ValueError(
"%r: a symbol can't contains whitespaces." % symbol)
except TypeError:
assert isinstance(symbol, type) and issubclass(symbol, Token), \
"A %r subclass requested, not %r." % (Token, symbol)
symbol, token_class = symbol.symbol, symbol
assert symbol in cls.symbol_table and cls.symbol_table[symbol] is token_class, \
"Token class %r is not registered." % token_class
else:
token_class = cls.symbol_table[symbol]
except KeyError:
# Register a new symbol and create a new custom class. The new class
# name is registered at parser class's module level.
if symbol not in cls.SYMBOLS:
raise NameError('%r is not a symbol of the parser %r.' %
(symbol, cls))
kwargs['symbol'] = symbol
if 'pattern' not in kwargs:
pattern = symbol_escape(
symbol) if len(symbol) > 1 else re.escape(symbol)
kwargs['pattern'] = pattern
label = kwargs.get('label', 'symbol')
if isinstance(label, tuple):
label = kwargs['label'] = MultiLabel(*label)
token_class_name = "_{}_{}_token".format(
symbol_to_identifier(symbol),
str(label).replace(' ', '_'))
token_class_bases = (getattr(cls, 'token_base_class', object), )
kwargs.update({
'__module__': cls.__module__,
'__qualname__': token_class_name,
'__return__': None
})
token_class = ABCMeta(token_class_name, token_class_bases, kwargs)
cls.symbol_table[symbol] = token_class
MutableSequence.register(token_class)
setattr(sys.modules[cls.__module__], token_class_name, token_class)
else:
for key, value in kwargs.items():
if key == 'lbp' and value > token_class.lbp:
token_class.lbp = value
elif key == 'rbp' and value > token_class.rbp:
token_class.rbp = value
elif callable(value):
setattr(token_class, key, value)
return token_class
