完整代码怎么修改，import contextlib
import copy
import functools
import pprint
import textwrap
import typing
import blinker
# 新版本 blinker 中的等效调用
from blinker import saferef # 替代原 _saferef
from seleniumwire.thirdparty.mitmproxy import exceptions
from seleniumwire.thirdparty.mitmproxy.utils import typecheck
"""
The base implementation for Options.
"""
unset = object()
class _Option:
__slots__ = ("name", "typespec", "value", "_default", "choices", "help")
def __init__(
self,
name: str,
typespec: typing.Union[type, object], # object for Optional[x], which is not a type.
default: typing.Any,
help: str,
choices: typing.Optional[typing.Sequence[str]]
) -> None:
typecheck.check_option_type(name, default, typespec)
self.name = name
self.typespec = typespec
self._default = default
self.value = unset
self.help = textwrap.dedent(help).strip().replace("\n", " ")
self.choices = choices
def __repr__(self):
return "{value} [{type}]".format(value=self.current(), type=self.typespec)
@property
def default(self):
return copy.deepcopy(self._default)
def current(self) -> typing.Any:
if self.value is unset:
v = self.default
else:
v = self.value
return copy.deepcopy(v)
def set(self, value: typing.Any) -> None:
typecheck.check_option_type(self.name, value, self.typespec)
self.value = value
def reset(self) -> None:
self.value = unset
def has_changed(self) -> bool:
return self.current() != self.default
def __eq__(self, other) -> bool:
for i in self.__slots__:
if getattr(self, i) != getattr(other, i):
return False
return True
def __deepcopy__(self, _):
o = _Option(
self.name, self.typespec, self.default, self.help, self.choices
)
if self.has_changed():
o.value = self.current()
return o
class OptManager:
"""
OptManager is the base class from which Options objects are derived.
.changed is a blinker Signal that triggers whenever options are
updated. If any handler in the chain raises an exceptions.OptionsError
exception, all changes are rolled back, the exception is suppressed,
and the .errored signal is notified.
Optmanager always returns a deep copy of options to ensure that
mutation doesn't change the option state inadvertently.
"""
def __init__(self):
self.deferred: typing.Dict[str, str] = {}
self.changed = blinker.Signal()
self.errored = blinker.Signal()
# Options must be the last attribute here - after that, we raise an
# error for attribute assigment to unknown options.
self._options: typing.Dict[str, typing.Any] = {}
def add_option(
self,
name: str,
typespec: typing.Union[type, object],
default: typing.Any,
help: str,
choices: typing.Optional[typing.Sequence[str]] = None
) -> None:
self._options[name] = _Option(name, typespec, default, help, choices)
self.changed.send(self, updated={name})
@contextlib.contextmanager
def rollback(self, updated, reraise=False):
old = copy.deepcopy(self._options)
try:
yield
except exceptions.OptionsError as e:
# Notify error handlers
self.errored.send(self, exc=e)
# Rollback
self.__dict__["_options"] = old
self.changed.send(self, updated=updated)
if reraise:
raise e
def subscribe(self, func, opts):
"""
Subscribe a callable to the .changed signal, but only for a
specified list of options. The callable should accept arguments
(options, updated), and may raise an OptionsError.
The event will automatically be unsubscribed if the callable goes out of scope.
"""
for i in opts:
if i not in self._options:
raise exceptions.OptionsError("No such option: %s" % i)
# We reuse blinker's safe reference functionality to cope with weakrefs
# to bound methods.
func = blinker._saferef.safe_ref(func)
@functools.wraps(func)
def _call(options, updated):
if updated.intersection(set(opts)):
f = func()
if f:
f(options, updated)
else:
self.changed.disconnect(_call)
# Our wrapper function goes out of scope immediately, so we have to set
# weakrefs to false. This means we need to keep our own weakref, and
# clean up the hook when it's gone.
self.changed.connect(_call, weak=False)
def __eq__(self, other):
if isinstance(other, OptManager):
return self._options == other._options
return False
def __deepcopy__(self, memodict = None):
o = OptManager()
o.__dict__["_options"] = copy.deepcopy(self._options, memodict)
return o
__copy__ = __deepcopy__
def __getattr__(self, attr):
if attr in self._options:
return self._options[attr].current()
else:
raise AttributeError("No such option: %s" % attr)
def __setattr__(self, attr, value):
# This is slightly tricky. We allow attributes to be set on the instance
# until we have an _options attribute. After that, assignment is sent to
# the update function, and will raise an error for unknown options.
opts = self.__dict__.get("_options")
if not opts:
super().__setattr__(attr, value)
else:
self.update(**{attr: value})
def keys(self):
return set(self._options.keys())
def items(self):
return self._options.items()
def __contains__(self, k):
return k in self._options
def reset(self):
"""
Restore defaults for all options.
"""
for o in self._options.values():
o.reset()
self.changed.send(self, updated=set(self._options.keys()))
def update_known(self, **kwargs):
"""
Update and set all known options from kwargs. Returns a dictionary
of unknown options.
"""
known, unknown = {}, {}
for k, v in kwargs.items():
if k in self._options:
known[k] = v
else:
unknown[k] = v
updated = set(known.keys())
if updated:
with self.rollback(updated, reraise=True):
for k, v in known.items():
self._options[k].set(v)
self.changed.send(self, updated=updated)
return unknown
def update_defer(self, **kwargs):
unknown = self.update_known(**kwargs)
self.deferred.update(unknown)
def update(self, **kwargs):
u = self.update_known(**kwargs)
if u:
raise KeyError("Unknown options: %s" % ", ".join(u.keys()))
def setter(self, attr):
"""
Generate a setter for a given attribute. This returns a callable
taking a single argument.
"""
if attr not in self._options:
raise KeyError("No such option: %s" % attr)
def setter(x):
setattr(self, attr, x)
return setter
def toggler(self, attr):
"""
Generate a toggler for a boolean attribute. This returns a callable
that takes no arguments.
"""
if attr not in self._options:
raise KeyError("No such option: %s" % attr)
o = self._options[attr]
if o.typespec != bool:
raise ValueError("Toggler can only be used with boolean options")
def toggle():
setattr(self, attr, not getattr(self, attr))
return toggle
def default(self, option: str) -> typing.Any:
return self._options[option].default
def has_changed(self, option):
"""
Has the option changed from the default?
"""
return self._options[option].has_changed()
def merge(self, opts):
"""
Merge a dict of options into this object. Options that have None
value are ignored. Lists and tuples are appended to the current
option value.
"""
toset = {}
for k, v in opts.items():
if v is not None:
if isinstance(v, (list, tuple)):
toset[k] = getattr(self, k) + v
else:
toset[k] = v
self.update(**toset)
def __repr__(self):
options = pprint.pformat(self._options, indent=4).strip(" {}")
if "\n" in options:
options = "\n " + options + "\n"
return "{mod}.{cls}({{{options}}})".format(
mod=type(self).__module__,
cls=type(self).__name__,
options=options
)
def set(self, *spec, defer=False):
"""
Takes a list of set specification in standard form (option=value).
Options that are known are updated immediately. If defer is true,
options that are not known are deferred, and will be set once they
are added.
"""
vals = {}
unknown = {}
for i in spec:
parts = i.split("=", maxsplit=1)
if len(parts) == 1:
optname, optval = parts[0], None
else:
optname, optval = parts[0], parts[1]
if optname in self._options:
vals[optname] = self.parse_setval(self._options[optname], optval)
else:
unknown[optname] = optval
if defer:
self.deferred.update(unknown)
elif unknown:
raise exceptions.OptionsError("Unknown options: %s" % ", ".join(unknown.keys()))
self.update(**vals)
def process_deferred(self):
"""
Processes options that were deferred in previous calls to set, and
have since been added.
"""
update = {}
for optname, optval in self.deferred.items():
if optname in self._options:
optval = self.parse_setval(self._options[optname], optval)
update[optname] = optval
self.update(**update)
for k in update.keys():
del self.deferred[k]
def parse_setval(self, o: _Option, optstr: typing.Optional[str]) -> typing.Any:
"""
Convert a string to a value appropriate for the option type.
"""
if o.typespec in (str, typing.Optional[str]):
return optstr
elif o.typespec in (int, typing.Optional[int]):
if optstr:
try:
return int(optstr)
except ValueError:
raise exceptions.OptionsError("Not an integer: %s" % optstr)
elif o.typespec == int:
raise exceptions.OptionsError("Option is required: %s" % o.name)
else:
return None
elif o.typespec == bool:
if optstr == "toggle":
return not o.current()
if not optstr or optstr == "true":
return True
elif optstr == "false":
return False
else:
raise exceptions.OptionsError(
"Boolean must be \"true\", \"false\", or have the value " "omitted (a synonym for \"true\")."
)
elif o.typespec == typing.Sequence[str]:
if not optstr:
return []
else:
return getattr(self, o.name) + [optstr]
raise NotImplementedError("Unsupported option type: %s", o.typespec)
def make_parser(self, parser, optname, metavar=None, short=None):
"""
Auto-Create a command-line parser entry for a named option. If the
option does not exist, it is ignored.
"""
if optname not in self._options:
return
o = self._options[optname]
def mkf(l, s):
l = l.replace("_", "-")
f = ["--%s" % l]
if s:
f.append("-" + s)
return f
flags = mkf(optname, short)
if o.typespec == bool:
g = parser.add_mutually_exclusive_group(required=False)
onf = mkf(optname, None)
offf = mkf("no-" + optname, None)
# The short option for a bool goes to whatever is NOT the default
if short:
if o.default:
offf = mkf("no-" + optname, short)
else:
onf = mkf(optname, short)
g.add_argument(
*offf,
action="store_false",
dest=optname,
)
g.add_argument(
*onf,
action="store_true",
dest=optname,
help=o.help
)
parser.set_defaults(**{optname: None})
elif o.typespec in (int, typing.Optional[int]):
parser.add_argument(
*flags,
action="store",
type=int,
dest=optname,
help=o.help,
metavar=metavar,
)
elif o.typespec in (str, typing.Optional[str]):
parser.add_argument(
*flags,
action="store",
type=str,
dest=optname,
help=o.help,
metavar=metavar,
choices=o.choices
)
elif o.typespec == typing.Sequence[str]:
parser.add_argument(
*flags,
action="append",
type=str,
dest=optname,
help=o.help + " May be passed multiple times.",
metavar=metavar,
choices=o.choices,
)
else:
raise ValueError("Unsupported option type: %s", o.typespec)
def dump_dicts(opts, keys: typing.List[str]=None):
"""
Dumps the options into a list of dict object.
Return: A list like: { "anticache": { type: "bool", default: false, value: true, help: "help text"} }
"""
options_dict = {}
keys = keys if keys else opts.keys()
for k in sorted(keys):
o = opts._options[k]
t = typecheck.typespec_to_str(o.typespec)
option = {
'type': t,
'default': o.default,
'value': o.current(),
'help': o.help,
'choices': o.choices
}
options_dict[k] = option
return options_dict
本文档介绍了基于C语言的语法分析器的实现，主要采用自顶向下的预测分析技术，详细阐述了预测分析法的原理和步骤，包括LL(1)文法的检查、预测分析表的构造以及错误处理机制。同时，还讨论了C语言文法设计，从函数定义到各种语句声明的文法结构。
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