FM / python3.10

/usr/lib/python3.10

Name	Size	Mode	Actions
asyncio/	-	0755	rm
collections/	-	0755	rm
concurrent/	-	0755	rm
config-3.10-x86_64-linux-gnu/	-	0755	rm
ctypes/	-	0755	rm
curses/	-	0755	rm
dbm/	-	0755	rm
distutils/	-	0755	rm
email/	-	0755	rm
encodings/	-	0755	rm
html/	-	0755	rm
http/	-	0755	rm
importlib/	-	0755	rm
json/	-	0755	rm
lib-dynload/	-	0755	rm
lib2to3/	-	0755	rm
logging/	-	0755	rm
multiprocessing/	-	0755	rm
pydoc_data/	-	0755	rm
sqlite3/	-	0755	rm
test/	-	0755	rm
unittest/	-	0755	rm
urllib/	-	0755	rm
venv/	-	0755	rm
wsgiref/	-	0755	rm
xml/	-	0755	rm
xmlrpc/	-	0755	rm
zoneinfo/	-	0755	rm
__pycache__/	-	0755	rm
abc.py	6522	0644	edit dl rm
aifc.py	32605	0644	edit dl rm
antigravity.py	500	0644	edit dl rm
argparse.py	98839	0644	edit dl rm
ast.py	59900	0644	edit dl rm
asynchat.py	11520	0644	edit dl rm
asyncore.py	20268	0644	edit dl rm
base64.py	20846	0755	edit dl rm
bdb.py	32396	0644	edit dl rm
binhex.py	14784	0644	edit dl rm
bisect.py	3135	0644	edit dl rm
bz2.py	11847	0644	edit dl rm
calendar.py	24575	0644	edit dl rm
cgi.py	34099	0755	edit dl rm
cgitb.py	12096	0644	edit dl rm
chunk.py	5435	0644	edit dl rm
cmd.py	14860	0644	edit dl rm
code.py	10622	0644	edit dl rm
codecs.py	36714	0644	edit dl rm
codeop.py	5609	0644	edit dl rm
colorsys.py	4017	0644	edit dl rm
compileall.py	20252	0644	edit dl rm
configparser.py	54612	0644	edit dl rm
contextlib.py	25882	0644	edit dl rm
contextvars.py	129	0644	edit dl rm
copy.py	8681	0644	edit dl rm
copyreg.py	7426	0644	edit dl rm
cProfile.py	6347	0755	edit dl rm
crypt.py	3848	0644	edit dl rm
csv.py	16030	0644	edit dl rm
dataclasses.py	56390	0644	edit dl rm
datetime.py	88086	0644	edit dl rm
decimal.py	320	0644	edit dl rm
difflib.py	83308	0644	edit dl rm
dis.py	20020	0644	edit dl rm
doctest.py	105143	0644	edit dl rm
enum.py	39831	0644	edit dl rm
filecmp.py	10178	0644	edit dl rm
fileinput.py	16442	0644	edit dl rm
fnmatch.py	6713	0644	edit dl rm
fractions.py	28242	0644	edit dl rm
ftplib.py	36001	0644	edit dl rm
functools.py	38076	0644	edit dl rm
genericpath.py	4975	0644	edit dl rm
getopt.py	7489	0644	edit dl rm
getpass.py	5990	0644	edit dl rm
gettext.py	27693	0644	edit dl rm
glob.py	7888	0644	edit dl rm
graphlib.py	9573	0644	edit dl rm
gzip.py	21849	0644	edit dl rm
hashlib.py	10229	0644	edit dl rm
heapq.py	22877	0644	edit dl rm
hmac.py	7717	0644	edit dl rm
imaplib.py	54866	0644	edit dl rm
imghdr.py	3808	0644	edit dl rm
imp.py	10591	0644	edit dl rm
inspect.py	124378	0644	edit dl rm
io.py	4196	0644	edit dl rm
ipaddress.py	77780	0644	edit dl rm
keyword.py	1061	0644	edit dl rm
LICENSE.txt	13936	0644	edit dl rm
linecache.py	5690	0644	edit dl rm
locale.py	78128	0644	edit dl rm
lzma.py	13277	0644	edit dl rm
mailbox.py	78794	0644	edit dl rm
mailcap.py	9116	0644	edit dl rm
mimetypes.py	22539	0644	edit dl rm
modulefinder.py	24401	0644	edit dl rm
netrc.py	5747	0644	edit dl rm
nntplib.py	41023	0644	edit dl rm
ntpath.py	27561	0644	edit dl rm
nturl2path.py	2887	0644	edit dl rm
numbers.py	10348	0644	edit dl rm
opcode.py	5902	0644	edit dl rm
operator.py	10751	0644	edit dl rm
optparse.py	60369	0644	edit dl rm
os.py	39557	0644	edit dl rm
pathlib.py	49575	0644	edit dl rm
pdb.py	63225	0755	edit dl rm
pickle.py	64949	0644	edit dl rm
pickletools.py	93486	0644	edit dl rm
pipes.py	8914	0644	edit dl rm
pkgutil.py	24576	0644	edit dl rm
platform.py	42022	0755	edit dl rm
plistlib.py	28592	0644	edit dl rm
poplib.py	15198	0644	edit dl rm
posixpath.py	16123	0644	edit dl rm
pprint.py	24444	0644	edit dl rm
profile.py	22883	0755	edit dl rm
pstats.py	29326	0644	edit dl rm
pty.py	5213	0644	edit dl rm
pyclbr.py	11396	0644	edit dl rm
pydoc.py	109884	0755	edit dl rm
py_compile.py	7878	0644	edit dl rm
queue.py	11496	0644	edit dl rm
quopri.py	7267	0755	edit dl rm
random.py	33221	0644	edit dl rm
re.py	15860	0644	edit dl rm
reprlib.py	5267	0644	edit dl rm
rlcompleter.py	7817	0644	edit dl rm
runpy.py	13111	0644	edit dl rm
sched.py	6351	0644	edit dl rm
secrets.py	2036	0644	edit dl rm
selectors.py	19536	0644	edit dl rm
shelve.py	8560	0644	edit dl rm
shlex.py	13501	0644	edit dl rm
shutil.py	54572	0644	edit dl rm
signal.py	2438	0644	edit dl rm
site.py	23667	0644	edit dl rm
sitecustomize.py	155	0644	edit dl rm
smtpd.py	35165	0755	edit dl rm
smtplib.py	45418	0755	edit dl rm
sndhdr.py	7099	0644	edit dl rm
socket.py	36785	0644	edit dl rm
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sre_compile.py	27973	0644	edit dl rm
sre_constants.py	7177	0644	edit dl rm
sre_parse.py	40779	0644	edit dl rm
ssl.py	53725	0644	edit dl rm
stat.py	5485	0644	edit dl rm
statistics.py	43205	0644	edit dl rm
string.py	10566	0644	edit dl rm
stringprep.py	12917	0644	edit dl rm
struct.py	257	0644	edit dl rm
subprocess.py	84917	0644	edit dl rm
sunau.py	18158	0644	edit dl rm
symtable.py	10217	0644	edit dl rm
sysconfig.py	29398	0644	edit dl rm
tabnanny.py	11299	0755	edit dl rm
tarfile.py	108332	0755	edit dl rm
telnetlib.py	23254	0644	edit dl rm
tempfile.py	34567	0644	edit dl rm
textwrap.py	19772	0644	edit dl rm
this.py	1003	0644	edit dl rm
threading.py	57200	0644	edit dl rm
timeit.py	13495	0755	edit dl rm
token.py	2386	0644	edit dl rm
tokenize.py	25921	0644	edit dl rm
trace.py	29215	0755	edit dl rm
traceback.py	26222	0644	edit dl rm
tracemalloc.py	18047	0644	edit dl rm
tty.py	879	0644	edit dl rm
turtle.py	143760	0644	edit dl rm
types.py	10117	0644	edit dl rm
typing.py	92557	0644	edit dl rm
uu.py	7300	0755	edit dl rm
uuid.py	27500	0644	edit dl rm
warnings.py	19688	0644	edit dl rm
wave.py	18004	0644	edit dl rm
weakref.py	21560	0644	edit dl rm
webbrowser.py	24739	0755	edit dl rm
xdrlib.py	5913	0644	edit dl rm
zipapp.py	7535	0644	edit dl rm
zipfile.py	90851	0644	edit dl rm
zipimport.py	30891	0644	edit dl rm
_aix_support.py	3270	0644	edit dl rm
_bootsubprocess.py	2675	0644	edit dl rm
_collections_abc.py	32284	0644	edit dl rm
_compat_pickle.py	8749	0644	edit dl rm
_compression.py	5681	0644	edit dl rm
_distutils_system_mod.py	6312	0644	edit dl rm
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_osx_support.py	21787	0644	edit dl rm
_pydecimal.py	228676	0644	edit dl rm
_pyio.py	94467	0644	edit dl rm
_py_abc.py	6189	0644	edit dl rm
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_sysconfigdata__linux_x86_64-linux-gnu.py	27484	0644	edit dl rm
_sysconfigdata__x86_64-linux-gnu.py	27484	0644	edit dl rm
_threading_local.py	7220	0644	edit dl rm
_weakrefset.py	5923	0644	edit dl rm
__future__.py	5155	0644	edit dl rm
__phello__.foo.py	64	0644	edit dl rm

Edit: /usr/lib/python3.10/sre_parse.py (40779B)

#
# Secret Labs' Regular Expression Engine
#
# convert re-style regular expression to sre pattern
#
# Copyright (c) 1998-2001 by Secret Labs AB.  All rights reserved.
#
# See the sre.py file for information on usage and redistribution.
#

"""Internal support module for sre"""

# XXX: show string offset and offending character for all errors

from sre_constants import *

SPECIAL_CHARS = ".\\[{()*+?^$|"
REPEAT_CHARS = "*+?{"

DIGITS = frozenset("0123456789")

OCTDIGITS = frozenset("01234567")
HEXDIGITS = frozenset("0123456789abcdefABCDEF")
ASCIILETTERS = frozenset("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")

WHITESPACE = frozenset(" \t\n\r\v\f")

_REPEATCODES = frozenset({MIN_REPEAT, MAX_REPEAT})
_UNITCODES = frozenset({ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY})

ESCAPES = {
    r"\a": (LITERAL, ord("\a")),
    r"\b": (LITERAL, ord("\b")),
    r"\f": (LITERAL, ord("\f")),
    r"\n": (LITERAL, ord("\n")),
    r"\r": (LITERAL, ord("\r")),
    r"\t": (LITERAL, ord("\t")),
    r"\v": (LITERAL, ord("\v")),
    r"\\": (LITERAL, ord("\\"))
}

CATEGORIES = {
    r"\A": (AT, AT_BEGINNING_STRING), # start of string
    r"\b": (AT, AT_BOUNDARY),
    r"\B": (AT, AT_NON_BOUNDARY),
    r"\d": (IN, [(CATEGORY, CATEGORY_DIGIT)]),
    r"\D": (IN, [(CATEGORY, CATEGORY_NOT_DIGIT)]),
    r"\s": (IN, [(CATEGORY, CATEGORY_SPACE)]),
    r"\S": (IN, [(CATEGORY, CATEGORY_NOT_SPACE)]),
    r"\w": (IN, [(CATEGORY, CATEGORY_WORD)]),
    r"\W": (IN, [(CATEGORY, CATEGORY_NOT_WORD)]),
    r"\Z": (AT, AT_END_STRING), # end of string
}

FLAGS = {
    # standard flags
    "i": SRE_FLAG_IGNORECASE,
    "L": SRE_FLAG_LOCALE,
    "m": SRE_FLAG_MULTILINE,
    "s": SRE_FLAG_DOTALL,
    "x": SRE_FLAG_VERBOSE,
    # extensions
    "a": SRE_FLAG_ASCII,
    "t": SRE_FLAG_TEMPLATE,
    "u": SRE_FLAG_UNICODE,
}

TYPE_FLAGS = SRE_FLAG_ASCII | SRE_FLAG_LOCALE | SRE_FLAG_UNICODE
GLOBAL_FLAGS = SRE_FLAG_DEBUG | SRE_FLAG_TEMPLATE

class Verbose(Exception):
    pass

class State:
    # keeps track of state for parsing
    def __init__(self):
        self.flags = 0
        self.groupdict = {}
        self.groupwidths = [None]  # group 0
        self.lookbehindgroups = None
        self.grouprefpos = {}
    @property
    def groups(self):
        return len(self.groupwidths)
    def opengroup(self, name=None):
        gid = self.groups
        self.groupwidths.append(None)
        if self.groups > MAXGROUPS:
            raise error("too many groups")
        if name is not None:
            ogid = self.groupdict.get(name, None)
            if ogid is not None:
                raise error("redefinition of group name %r as group %d; "
                            "was group %d" % (name, gid,  ogid))
            self.groupdict[name] = gid
        return gid
    def closegroup(self, gid, p):
        self.groupwidths[gid] = p.getwidth()
    def checkgroup(self, gid):
        return gid < self.groups and self.groupwidths[gid] is not None

def checklookbehindgroup(self, gid, source):
        if self.lookbehindgroups is not None:
            if not self.checkgroup(gid):
                raise source.error('cannot refer to an open group')
            if gid >= self.lookbehindgroups:
                raise source.error('cannot refer to group defined in the same '
                                   'lookbehind subpattern')

class SubPattern:
    # a subpattern, in intermediate form
    def __init__(self, state, data=None):
        self.state = state
        if data is None:
            data = []
        self.data = data
        self.width = None

def dump(self, level=0):
        nl = True
        seqtypes = (tuple, list)
        for op, av in self.data:
            print(level*"  " + str(op), end='')
            if op is IN:
                # member sublanguage
                print()
                for op, a in av:
                    print((level+1)*"  " + str(op), a)
            elif op is BRANCH:
                print()
                for i, a in enumerate(av[1]):
                    if i:
                        print(level*"  " + "OR")
                    a.dump(level+1)
            elif op is GROUPREF_EXISTS:
                condgroup, item_yes, item_no = av
                print('', condgroup)
                item_yes.dump(level+1)
                if item_no:
                    print(level*"  " + "ELSE")
                    item_no.dump(level+1)
            elif isinstance(av, seqtypes):
                nl = False
                for a in av:
                    if isinstance(a, SubPattern):
                        if not nl:
                            print()
                        a.dump(level+1)
                        nl = True
                    else:
                        if not nl:
                            print(' ', end='')
                        print(a, end='')
                        nl = False
                if not nl:
                    print()
            else:
                print('', av)
    def __repr__(self):
        return repr(self.data)
    def __len__(self):
        return len(self.data)
    def __delitem__(self, index):
        del self.data[index]
    def __getitem__(self, index):
        if isinstance(index, slice):
            return SubPattern(self.state, self.data[index])
        return self.data[index]
    def __setitem__(self, index, code):
        self.data[index] = code
    def insert(self, index, code):
        self.data.insert(index, code)
    def append(self, code):
        self.data.append(code)
    def getwidth(self):
        # determine the width (min, max) for this subpattern
        if self.width is not None:
            return self.width
        lo = hi = 0
        for op, av in self.data:
            if op is BRANCH:
                i = MAXREPEAT - 1
                j = 0
                for av in av[1]:
                    l, h = av.getwidth()
                    i = min(i, l)
                    j = max(j, h)
                lo = lo + i
                hi = hi + j
            elif op is CALL:
                i, j = av.getwidth()
                lo = lo + i
                hi = hi + j
            elif op is SUBPATTERN:
                i, j = av[-1].getwidth()
                lo = lo + i
                hi = hi + j
            elif op in _REPEATCODES:
                i, j = av[2].getwidth()
                lo = lo + i * av[0]
                hi = hi + j * av[1]
            elif op in _UNITCODES:
                lo = lo + 1
                hi = hi + 1
            elif op is GROUPREF:
                i, j = self.state.groupwidths[av]
                lo = lo + i
                hi = hi + j
            elif op is GROUPREF_EXISTS:
                i, j = av[1].getwidth()
                if av[2] is not None:
                    l, h = av[2].getwidth()
                    i = min(i, l)
                    j = max(j, h)
                else:
                    i = 0
                lo = lo + i
                hi = hi + j
            elif op is SUCCESS:
                break
        self.width = min(lo, MAXREPEAT - 1), min(hi, MAXREPEAT)
        return self.width

class Tokenizer:
    def __init__(self, string):
        self.istext = isinstance(string, str)
        self.string = string
        if not self.istext:
            string = str(string, 'latin1')
        self.decoded_string = string
        self.index = 0
        self.next = None
        self.__next()
    def __next(self):
        index = self.index
        try:
            char = self.decoded_string[index]
        except IndexError:
            self.next = None
            return
        if char == "\\":
            index += 1
            try:
                char += self.decoded_string[index]
            except IndexError:
                raise error("bad escape (end of pattern)",
                            self.string, len(self.string) - 1) from None
        self.index = index + 1
        self.next = char
    def match(self, char):
        if char == self.next:
            self.__next()
            return True
        return False
    def get(self):
        this = self.next
        self.__next()
        return this
    def getwhile(self, n, charset):
        result = ''
        for _ in range(n):
            c = self.next
            if c not in charset:
                break
            result += c
            self.__next()
        return result
    def getuntil(self, terminator, name):
        result = ''
        while True:
            c = self.next
            self.__next()
            if c is None:
                if not result:
                    raise self.error("missing " + name)
                raise self.error("missing %s, unterminated name" % terminator,
                                 len(result))
            if c == terminator:
                if not result:
                    raise self.error("missing " + name, 1)
                break
            result += c
        return result
    @property
    def pos(self):
        return self.index - len(self.next or '')
    def tell(self):
        return self.index - len(self.next or '')
    def seek(self, index):
        self.index = index
        self.__next()

def error(self, msg, offset=0):
        return error(msg, self.string, self.tell() - offset)

def _class_escape(source, escape):
    # handle escape code inside character class
    code = ESCAPES.get(escape)
    if code:
        return code
    code = CATEGORIES.get(escape)
    if code and code[0] is IN:
        return code
    try:
        c = escape[1:2]
        if c == "x":
            # hexadecimal escape (exactly two digits)
            escape += source.getwhile(2, HEXDIGITS)
            if len(escape) != 4:
                raise source.error("incomplete escape %s" % escape, len(escape))
            return LITERAL, int(escape[2:], 16)
        elif c == "u" and source.istext:
            # unicode escape (exactly four digits)
            escape += source.getwhile(4, HEXDIGITS)
            if len(escape) != 6:
                raise source.error("incomplete escape %s" % escape, len(escape))
            return LITERAL, int(escape[2:], 16)
        elif c == "U" and source.istext:
            # unicode escape (exactly eight digits)
            escape += source.getwhile(8, HEXDIGITS)
            if len(escape) != 10:
                raise source.error("incomplete escape %s" % escape, len(escape))
            c = int(escape[2:], 16)
            chr(c) # raise ValueError for invalid code
            return LITERAL, c
        elif c == "N" and source.istext:
            import unicodedata
            # named unicode escape e.g. \N{EM DASH}
            if not source.match('{'):
                raise source.error("missing {")
            charname = source.getuntil('}', 'character name')
            try:
                c = ord(unicodedata.lookup(charname))
            except (KeyError, TypeError):
                raise source.error("undefined character name %r" % charname,
                                   len(charname) + len(r'\N{}'))
            return LITERAL, c
        elif c in OCTDIGITS:
            # octal escape (up to three digits)
            escape += source.getwhile(2, OCTDIGITS)
            c = int(escape[1:], 8)
            if c > 0o377:
                raise source.error('octal escape value %s outside of '
                                   'range 0-0o377' % escape, len(escape))
            return LITERAL, c
        elif c in DIGITS:
            raise ValueError
        if len(escape) == 2:
            if c in ASCIILETTERS:
                raise source.error('bad escape %s' % escape, len(escape))
            return LITERAL, ord(escape[1])
    except ValueError:
        pass
    raise source.error("bad escape %s" % escape, len(escape))

def _escape(source, escape, state):
    # handle escape code in expression
    code = CATEGORIES.get(escape)
    if code:
        return code
    code = ESCAPES.get(escape)
    if code:
        return code
    try:
        c = escape[1:2]
        if c == "x":
            # hexadecimal escape
            escape += source.getwhile(2, HEXDIGITS)
            if len(escape) != 4:
                raise source.error("incomplete escape %s" % escape, len(escape))
            return LITERAL, int(escape[2:], 16)
        elif c == "u" and source.istext:
            # unicode escape (exactly four digits)
            escape += source.getwhile(4, HEXDIGITS)
            if len(escape) != 6:
                raise source.error("incomplete escape %s" % escape, len(escape))
            return LITERAL, int(escape[2:], 16)
        elif c == "U" and source.istext:
            # unicode escape (exactly eight digits)
            escape += source.getwhile(8, HEXDIGITS)
            if len(escape) != 10:
                raise source.error("incomplete escape %s" % escape, len(escape))
            c = int(escape[2:], 16)
            chr(c) # raise ValueError for invalid code
            return LITERAL, c
        elif c == "N" and source.istext:
            import unicodedata
            # named unicode escape e.g. \N{EM DASH}
            if not source.match('{'):
                raise source.error("missing {")
            charname = source.getuntil('}', 'character name')
            try:
                c = ord(unicodedata.lookup(charname))
            except (KeyError, TypeError):
                raise source.error("undefined character name %r" % charname,
                                   len(charname) + len(r'\N{}'))
            return LITERAL, c
        elif c == "0":
            # octal escape
            escape += source.getwhile(2, OCTDIGITS)
            return LITERAL, int(escape[1:], 8)
        elif c in DIGITS:
            # octal escape *or* decimal group reference (sigh)
            if source.next in DIGITS:
                escape += source.get()
                if (escape[1] in OCTDIGITS and escape[2] in OCTDIGITS and
                    source.next in OCTDIGITS):
                    # got three octal digits; this is an octal escape
                    escape += source.get()
                    c = int(escape[1:], 8)
                    if c > 0o377:
                        raise source.error('octal escape value %s outside of '
                                           'range 0-0o377' % escape,
                                           len(escape))
                    return LITERAL, c
            # not an octal escape, so this is a group reference
            group = int(escape[1:])
            if group < state.groups:
                if not state.checkgroup(group):
                    raise source.error("cannot refer to an open group",
                                       len(escape))
                state.checklookbehindgroup(group, source)
                return GROUPREF, group
            raise source.error("invalid group reference %d" % group, len(escape) - 1)
        if len(escape) == 2:
            if c in ASCIILETTERS:
                raise source.error("bad escape %s" % escape, len(escape))
            return LITERAL, ord(escape[1])
    except ValueError:
        pass
    raise source.error("bad escape %s" % escape, len(escape))

def _uniq(items):
    return list(dict.fromkeys(items))

def _parse_sub(source, state, verbose, nested):
    # parse an alternation: a|b|c

items = []
    itemsappend = items.append
    sourcematch = source.match
    start = source.tell()
    while True:
        itemsappend(_parse(source, state, verbose, nested + 1,
                           not nested and not items))
        if not sourcematch("|"):
            break

if len(items) == 1:
        return items[0]

subpattern = SubPattern(state)

# check if all items share a common prefix
    while True:
        prefix = None
        for item in items:
            if not item:
                break
            if prefix is None:
                prefix = item[0]
            elif item[0] != prefix:
                break
        else:
            # all subitems start with a common "prefix".
            # move it out of the branch
            for item in items:
                del item[0]
            subpattern.append(prefix)
            continue # check next one
        break

# check if the branch can be replaced by a character set
    set = []
    for item in items:
        if len(item) != 1:
            break
        op, av = item[0]
        if op is LITERAL:
            set.append((op, av))
        elif op is IN and av[0][0] is not NEGATE:
            set.extend(av)
        else:
            break
    else:
        # we can store this as a character set instead of a
        # branch (the compiler may optimize this even more)
        subpattern.append((IN, _uniq(set)))
        return subpattern

subpattern.append((BRANCH, (None, items)))
    return subpattern

def _parse(source, state, verbose, nested, first=False):
    # parse a simple pattern
    subpattern = SubPattern(state)

# precompute constants into local variables
    subpatternappend = subpattern.append
    sourceget = source.get
    sourcematch = source.match
    _len = len
    _ord = ord

while True:

this = source.next
        if this is None:
            break # end of pattern
        if this in "|)":
            break # end of subpattern
        sourceget()

if verbose:
            # skip whitespace and comments
            if this in WHITESPACE:
                continue
            if this == "#":
                while True:
                    this = sourceget()
                    if this is None or this == "\n":
                        break
                continue

if this[0] == "\\":
            code = _escape(source, this, state)
            subpatternappend(code)

elif this not in SPECIAL_CHARS:
            subpatternappend((LITERAL, _ord(this)))

elif this == "[":
            here = source.tell() - 1
            # character set
            set = []
            setappend = set.append
##          if sourcematch(":"):
##              pass # handle character classes
            if source.next == '[':
                import warnings
                warnings.warn(
                    'Possible nested set at position %d' % source.tell(),
                    FutureWarning, stacklevel=nested + 6
                )
            negate = sourcematch("^")
            # check remaining characters
            while True:
                this = sourceget()
                if this is None:
                    raise source.error("unterminated character set",
                                       source.tell() - here)
                if this == "]" and set:
                    break
                elif this[0] == "\\":
                    code1 = _class_escape(source, this)
                else:
                    if set and this in '-&~|' and source.next == this:
                        import warnings
                        warnings.warn(
                            'Possible set %s at position %d' % (
                                'difference' if this == '-' else
                                'intersection' if this == '&' else
                                'symmetric difference' if this == '~' else
                                'union',
                                source.tell() - 1),
                            FutureWarning, stacklevel=nested + 6
                        )
                    code1 = LITERAL, _ord(this)
                if sourcematch("-"):
                    # potential range
                    that = sourceget()
                    if that is None:
                        raise source.error("unterminated character set",
                                           source.tell() - here)
                    if that == "]":
                        if code1[0] is IN:
                            code1 = code1[1][0]
                        setappend(code1)
                        setappend((LITERAL, _ord("-")))
                        break
                    if that[0] == "\\":
                        code2 = _class_escape(source, that)
                    else:
                        if that == '-':
                            import warnings
                            warnings.warn(
                                'Possible set difference at position %d' % (
                                    source.tell() - 2),
                                FutureWarning, stacklevel=nested + 6
                            )
                        code2 = LITERAL, _ord(that)
                    if code1[0] != LITERAL or code2[0] != LITERAL:
                        msg = "bad character range %s-%s" % (this, that)
                        raise source.error(msg, len(this) + 1 + len(that))
                    lo = code1[1]
                    hi = code2[1]
                    if hi < lo:
                        msg = "bad character range %s-%s" % (this, that)
                        raise source.error(msg, len(this) + 1 + len(that))
                    setappend((RANGE, (lo, hi)))
                else:
                    if code1[0] is IN:
                        code1 = code1[1][0]
                    setappend(code1)

set = _uniq(set)
            # XXX: <fl> should move set optimization to compiler!
            if _len(set) == 1 and set[0][0] is LITERAL:
                # optimization
                if negate:
                    subpatternappend((NOT_LITERAL, set[0][1]))
                else:
                    subpatternappend(set[0])
            else:
                if negate:
                    set.insert(0, (NEGATE, None))
                # charmap optimization can't be added here because
                # global flags still are not known
                subpatternappend((IN, set))

elif this in REPEAT_CHARS:
            # repeat previous item
            here = source.tell()
            if this == "?":
                min, max = 0, 1
            elif this == "*":
                min, max = 0, MAXREPEAT

elif this == "+":
                min, max = 1, MAXREPEAT
            elif this == "{":
                if source.next == "}":
                    subpatternappend((LITERAL, _ord(this)))
                    continue

min, max = 0, MAXREPEAT
                lo = hi = ""
                while source.next in DIGITS:
                    lo += sourceget()
                if sourcematch(","):
                    while source.next in DIGITS:
                        hi += sourceget()
                else:
                    hi = lo
                if not sourcematch("}"):
                    subpatternappend((LITERAL, _ord(this)))
                    source.seek(here)
                    continue

if lo:
                    min = int(lo)
                    if min >= MAXREPEAT:
                        raise OverflowError("the repetition number is too large")
                if hi:
                    max = int(hi)
                    if max >= MAXREPEAT:
                        raise OverflowError("the repetition number is too large")
                    if max < min:
                        raise source.error("min repeat greater than max repeat",
                                           source.tell() - here)
            else:
                raise AssertionError("unsupported quantifier %r" % (char,))
            # figure out which item to repeat
            if subpattern:
                item = subpattern[-1:]
            else:
                item = None
            if not item or item[0][0] is AT:
                raise source.error("nothing to repeat",
                                   source.tell() - here + len(this))
            if item[0][0] in _REPEATCODES:
                raise source.error("multiple repeat",
                                   source.tell() - here + len(this))
            if item[0][0] is SUBPATTERN:
                group, add_flags, del_flags, p = item[0][1]
                if group is None and not add_flags and not del_flags:
                    item = p
            if sourcematch("?"):
                subpattern[-1] = (MIN_REPEAT, (min, max, item))
            else:
                subpattern[-1] = (MAX_REPEAT, (min, max, item))

elif this == ".":
            subpatternappend((ANY, None))

elif this == "(":
            start = source.tell() - 1
            group = True
            name = None
            add_flags = 0
            del_flags = 0
            if sourcematch("?"):
                # options
                char = sourceget()
                if char is None:
                    raise source.error("unexpected end of pattern")
                if char == "P":
                    # python extensions
                    if sourcematch("<"):
                        # named group: skip forward to end of name
                        name = source.getuntil(">", "group name")
                        if not name.isidentifier():
                            msg = "bad character in group name %r" % name
                            raise source.error(msg, len(name) + 1)
                    elif sourcematch("="):
                        # named backreference
                        name = source.getuntil(")", "group name")
                        if not name.isidentifier():
                            msg = "bad character in group name %r" % name
                            raise source.error(msg, len(name) + 1)
                        gid = state.groupdict.get(name)
                        if gid is None:
                            msg = "unknown group name %r" % name
                            raise source.error(msg, len(name) + 1)
                        if not state.checkgroup(gid):
                            raise source.error("cannot refer to an open group",
                                               len(name) + 1)
                        state.checklookbehindgroup(gid, source)
                        subpatternappend((GROUPREF, gid))
                        continue

else:
                        char = sourceget()
                        if char is None:
                            raise source.error("unexpected end of pattern")
                        raise source.error("unknown extension ?P" + char,
                                           len(char) + 2)
                elif char == ":":
                    # non-capturing group
                    group = None
                elif char == "#":
                    # comment
                    while True:
                        if source.next is None:
                            raise source.error("missing ), unterminated comment",
                                               source.tell() - start)
                        if sourceget() == ")":
                            break
                    continue

elif char in "=!<":
                    # lookahead assertions
                    dir = 1
                    if char == "<":
                        char = sourceget()
                        if char is None:
                            raise source.error("unexpected end of pattern")
                        if char not in "=!":
                            raise source.error("unknown extension ?<" + char,
                                               len(char) + 2)
                        dir = -1 # lookbehind
                        lookbehindgroups = state.lookbehindgroups
                        if lookbehindgroups is None:
                            state.lookbehindgroups = state.groups
                    p = _parse_sub(source, state, verbose, nested + 1)
                    if dir < 0:
                        if lookbehindgroups is None:
                            state.lookbehindgroups = None
                    if not sourcematch(")"):
                        raise source.error("missing ), unterminated subpattern",
                                           source.tell() - start)
                    if char == "=":
                        subpatternappend((ASSERT, (dir, p)))
                    else:
                        subpatternappend((ASSERT_NOT, (dir, p)))
                    continue

elif char == "(":
                    # conditional backreference group
                    condname = source.getuntil(")", "group name")
                    if condname.isidentifier():
                        condgroup = state.groupdict.get(condname)
                        if condgroup is None:
                            msg = "unknown group name %r" % condname
                            raise source.error(msg, len(condname) + 1)
                    else:
                        try:
                            condgroup = int(condname)
                            if condgroup < 0:
                                raise ValueError
                        except ValueError:
                            msg = "bad character in group name %r" % condname
                            raise source.error(msg, len(condname) + 1) from None
                        if not condgroup:
                            raise source.error("bad group number",
                                               len(condname) + 1)
                        if condgroup >= MAXGROUPS:
                            msg = "invalid group reference %d" % condgroup
                            raise source.error(msg, len(condname) + 1)
                        if condgroup not in state.grouprefpos:
                            state.grouprefpos[condgroup] = (
                                source.tell() - len(condname) - 1
                            )
                    state.checklookbehindgroup(condgroup, source)
                    item_yes = _parse(source, state, verbose, nested + 1)
                    if source.match("|"):
                        item_no = _parse(source, state, verbose, nested + 1)
                        if source.next == "|":
                            raise source.error("conditional backref with more than two branches")
                    else:
                        item_no = None
                    if not source.match(")"):
                        raise source.error("missing ), unterminated subpattern",
                                           source.tell() - start)
                    subpatternappend((GROUPREF_EXISTS, (condgroup, item_yes, item_no)))
                    continue

elif char in FLAGS or char == "-":
                    # flags
                    flags = _parse_flags(source, state, char)
                    if flags is None:  # global flags
                        if not first or subpattern:
                            import warnings
                            warnings.warn(
                                'Flags not at the start of the expression %r%s'
                                ' but at position %d' % (
                                    source.string[:20],  # truncate long regexes
                                    ' (truncated)' if len(source.string) > 20 else '',
                                    start,
                                ),
                                DeprecationWarning, stacklevel=nested + 6
                            )
                        if (state.flags & SRE_FLAG_VERBOSE) and not verbose:
                            raise Verbose
                        continue

add_flags, del_flags = flags
                    group = None
                else:
                    raise source.error("unknown extension ?" + char,
                                       len(char) + 1)

# parse group contents
            if group is not None:
                try:
                    group = state.opengroup(name)
                except error as err:
                    raise source.error(err.msg, len(name) + 1) from None
            sub_verbose = ((verbose or (add_flags & SRE_FLAG_VERBOSE)) and
                           not (del_flags & SRE_FLAG_VERBOSE))
            p = _parse_sub(source, state, sub_verbose, nested + 1)
            if not source.match(")"):
                raise source.error("missing ), unterminated subpattern",
                                   source.tell() - start)
            if group is not None:
                state.closegroup(group, p)
            subpatternappend((SUBPATTERN, (group, add_flags, del_flags, p)))

elif this == "^":
            subpatternappend((AT, AT_BEGINNING))

elif this == "$":
            subpatternappend((AT, AT_END))

else:
            raise AssertionError("unsupported special character %r" % (char,))

# unpack non-capturing groups
    for i in range(len(subpattern))[::-1]:
        op, av = subpattern[i]
        if op is SUBPATTERN:
            group, add_flags, del_flags, p = av
            if group is None and not add_flags and not del_flags:
                subpattern[i: i+1] = p

return subpattern

def _parse_flags(source, state, char):
    sourceget = source.get
    add_flags = 0
    del_flags = 0
    if char != "-":
        while True:
            flag = FLAGS[char]
            if source.istext:
                if char == 'L':
                    msg = "bad inline flags: cannot use 'L' flag with a str pattern"
                    raise source.error(msg)
            else:
                if char == 'u':
                    msg = "bad inline flags: cannot use 'u' flag with a bytes pattern"
                    raise source.error(msg)
            add_flags |= flag
            if (flag & TYPE_FLAGS) and (add_flags & TYPE_FLAGS) != flag:
                msg = "bad inline flags: flags 'a', 'u' and 'L' are incompatible"
                raise source.error(msg)
            char = sourceget()
            if char is None:
                raise source.error("missing -, : or )")
            if char in ")-:":
                break
            if char not in FLAGS:
                msg = "unknown flag" if char.isalpha() else "missing -, : or )"
                raise source.error(msg, len(char))
    if char == ")":
        state.flags |= add_flags
        return None
    if add_flags & GLOBAL_FLAGS:
        raise source.error("bad inline flags: cannot turn on global flag", 1)
    if char == "-":
        char = sourceget()
        if char is None:
            raise source.error("missing flag")
        if char not in FLAGS:
            msg = "unknown flag" if char.isalpha() else "missing flag"
            raise source.error(msg, len(char))
        while True:
            flag = FLAGS[char]
            if flag & TYPE_FLAGS:
                msg = "bad inline flags: cannot turn off flags 'a', 'u' and 'L'"
                raise source.error(msg)
            del_flags |= flag
            char = sourceget()
            if char is None:
                raise source.error("missing :")
            if char == ":":
                break
            if char not in FLAGS:
                msg = "unknown flag" if char.isalpha() else "missing :"
                raise source.error(msg, len(char))
    assert char == ":"
    if del_flags & GLOBAL_FLAGS:
        raise source.error("bad inline flags: cannot turn off global flag", 1)
    if add_flags & del_flags:
        raise source.error("bad inline flags: flag turned on and off", 1)
    return add_flags, del_flags

def fix_flags(src, flags):
    # Check and fix flags according to the type of pattern (str or bytes)
    if isinstance(src, str):
        if flags & SRE_FLAG_LOCALE:
            raise ValueError("cannot use LOCALE flag with a str pattern")
        if not flags & SRE_FLAG_ASCII:
            flags |= SRE_FLAG_UNICODE
        elif flags & SRE_FLAG_UNICODE:
            raise ValueError("ASCII and UNICODE flags are incompatible")
    else:
        if flags & SRE_FLAG_UNICODE:
            raise ValueError("cannot use UNICODE flag with a bytes pattern")
        if flags & SRE_FLAG_LOCALE and flags & SRE_FLAG_ASCII:
            raise ValueError("ASCII and LOCALE flags are incompatible")
    return flags

def parse(str, flags=0, state=None):
    # parse 're' pattern into list of (opcode, argument) tuples

source = Tokenizer(str)

if state is None:
        state = State()
    state.flags = flags
    state.str = str

try:
        p = _parse_sub(source, state, flags & SRE_FLAG_VERBOSE, 0)
    except Verbose:
        # the VERBOSE flag was switched on inside the pattern.  to be
        # on the safe side, we'll parse the whole thing again...
        state = State()
        state.flags = flags | SRE_FLAG_VERBOSE
        state.str = str
        source.seek(0)
        p = _parse_sub(source, state, True, 0)

p.state.flags = fix_flags(str, p.state.flags)

if source.next is not None:
        assert source.next == ")"
        raise source.error("unbalanced parenthesis")

for g in p.state.grouprefpos:
        if g >= p.state.groups:
            msg = "invalid group reference %d" % g
            raise error(msg, str, p.state.grouprefpos[g])

if flags & SRE_FLAG_DEBUG:
        p.dump()

return p

def parse_template(source, state):
    # parse 're' replacement string into list of literals and
    # group references
    s = Tokenizer(source)
    sget = s.get
    groups = []
    literals = []
    literal = []
    lappend = literal.append
    def addgroup(index, pos):
        if index > state.groups:
            raise s.error("invalid group reference %d" % index, pos)
        if literal:
            literals.append(''.join(literal))
            del literal[:]
        groups.append((len(literals), index))
        literals.append(None)
    groupindex = state.groupindex
    while True:
        this = sget()
        if this is None:
            break # end of replacement string
        if this[0] == "\\":
            # group
            c = this[1]
            if c == "g":
                name = ""
                if not s.match("<"):
                    raise s.error("missing <")
                name = s.getuntil(">", "group name")
                if name.isidentifier():
                    try:
                        index = groupindex[name]
                    except KeyError:
                        raise IndexError("unknown group name %r" % name)
                else:
                    try:
                        index = int(name)
                        if index < 0:
                            raise ValueError
                    except ValueError:
                        raise s.error("bad character in group name %r" % name,
                                      len(name) + 1) from None
                    if index >= MAXGROUPS:
                        raise s.error("invalid group reference %d" % index,
                                      len(name) + 1)
                addgroup(index, len(name) + 1)
            elif c == "0":
                if s.next in OCTDIGITS:
                    this += sget()
                    if s.next in OCTDIGITS:
                        this += sget()
                lappend(chr(int(this[1:], 8) & 0xff))
            elif c in DIGITS:
                isoctal = False
                if s.next in DIGITS:
                    this += sget()
                    if (c in OCTDIGITS and this[2] in OCTDIGITS and
                        s.next in OCTDIGITS):
                        this += sget()
                        isoctal = True
                        c = int(this[1:], 8)
                        if c > 0o377:
                            raise s.error('octal escape value %s outside of '
                                          'range 0-0o377' % this, len(this))
                        lappend(chr(c))
                if not isoctal:
                    addgroup(int(this[1:]), len(this) - 1)
            else:
                try:
                    this = chr(ESCAPES[this][1])
                except KeyError:
                    if c in ASCIILETTERS:
                        raise s.error('bad escape %s' % this, len(this))
                lappend(this)
        else:
            lappend(this)
    if literal:
        literals.append(''.join(literal))
    if not isinstance(source, str):
        # The tokenizer implicitly decodes bytes objects as latin-1, we must
        # therefore re-encode the final representation.
        literals = [None if s is None else s.encode('latin-1') for s in literals]
    return groups, literals

def expand_template(template, match):
    g = match.group
    empty = match.string[:0]
    groups, literals = template
    literals = literals[:]
    try:
        for index, group in groups:
            literals[index] = g(group) or empty
    except IndexError:
        raise error("invalid group reference %d" % index)
    return empty.join(literals)

cmd: