mirror of https://github.com/python/cpython
1085 lines
40 KiB
Python
1085 lines
40 KiB
Python
#
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# Secret Labs' Regular Expression Engine
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#
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# convert re-style regular expression to sre pattern
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#
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# Copyright (c) 1998-2001 by Secret Labs AB. All rights reserved.
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#
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# See the __init__.py file for information on usage and redistribution.
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#
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"""Internal support module for sre"""
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# XXX: show string offset and offending character for all errors
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from ._constants import *
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SPECIAL_CHARS = ".\\[{()*+?^$|"
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REPEAT_CHARS = "*+?{"
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DIGITS = frozenset("0123456789")
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OCTDIGITS = frozenset("01234567")
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HEXDIGITS = frozenset("0123456789abcdefABCDEF")
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ASCIILETTERS = frozenset("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
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WHITESPACE = frozenset(" \t\n\r\v\f")
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_REPEATCODES = frozenset({MIN_REPEAT, MAX_REPEAT, POSSESSIVE_REPEAT})
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_UNITCODES = frozenset({ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY})
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ESCAPES = {
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r"\a": (LITERAL, ord("\a")),
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r"\b": (LITERAL, ord("\b")),
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r"\f": (LITERAL, ord("\f")),
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r"\n": (LITERAL, ord("\n")),
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r"\r": (LITERAL, ord("\r")),
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r"\t": (LITERAL, ord("\t")),
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r"\v": (LITERAL, ord("\v")),
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r"\\": (LITERAL, ord("\\"))
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}
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CATEGORIES = {
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r"\A": (AT, AT_BEGINNING_STRING), # start of string
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r"\b": (AT, AT_BOUNDARY),
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r"\B": (AT, AT_NON_BOUNDARY),
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r"\d": (IN, [(CATEGORY, CATEGORY_DIGIT)]),
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r"\D": (IN, [(CATEGORY, CATEGORY_NOT_DIGIT)]),
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r"\s": (IN, [(CATEGORY, CATEGORY_SPACE)]),
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r"\S": (IN, [(CATEGORY, CATEGORY_NOT_SPACE)]),
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r"\w": (IN, [(CATEGORY, CATEGORY_WORD)]),
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r"\W": (IN, [(CATEGORY, CATEGORY_NOT_WORD)]),
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r"\Z": (AT, AT_END_STRING), # end of string
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}
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FLAGS = {
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# standard flags
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"i": SRE_FLAG_IGNORECASE,
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"L": SRE_FLAG_LOCALE,
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"m": SRE_FLAG_MULTILINE,
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"s": SRE_FLAG_DOTALL,
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"x": SRE_FLAG_VERBOSE,
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# extensions
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"a": SRE_FLAG_ASCII,
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"t": SRE_FLAG_TEMPLATE,
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"u": SRE_FLAG_UNICODE,
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}
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TYPE_FLAGS = SRE_FLAG_ASCII | SRE_FLAG_LOCALE | SRE_FLAG_UNICODE
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GLOBAL_FLAGS = SRE_FLAG_DEBUG | SRE_FLAG_TEMPLATE
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class State:
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# keeps track of state for parsing
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def __init__(self):
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self.flags = 0
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self.groupdict = {}
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self.groupwidths = [None] # group 0
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self.lookbehindgroups = None
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self.grouprefpos = {}
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@property
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def groups(self):
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return len(self.groupwidths)
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def opengroup(self, name=None):
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gid = self.groups
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self.groupwidths.append(None)
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if self.groups > MAXGROUPS:
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raise error("too many groups")
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if name is not None:
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ogid = self.groupdict.get(name, None)
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if ogid is not None:
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raise error("redefinition of group name %r as group %d; "
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"was group %d" % (name, gid, ogid))
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self.groupdict[name] = gid
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return gid
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def closegroup(self, gid, p):
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self.groupwidths[gid] = p.getwidth()
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def checkgroup(self, gid):
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return gid < self.groups and self.groupwidths[gid] is not None
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def checklookbehindgroup(self, gid, source):
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if self.lookbehindgroups is not None:
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if not self.checkgroup(gid):
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raise source.error('cannot refer to an open group')
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if gid >= self.lookbehindgroups:
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raise source.error('cannot refer to group defined in the same '
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'lookbehind subpattern')
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class SubPattern:
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# a subpattern, in intermediate form
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def __init__(self, state, data=None):
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self.state = state
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if data is None:
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data = []
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self.data = data
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self.width = None
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def dump(self, level=0):
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nl = True
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seqtypes = (tuple, list)
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for op, av in self.data:
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print(level*" " + str(op), end='')
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if op is IN:
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# member sublanguage
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print()
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for op, a in av:
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print((level+1)*" " + str(op), a)
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elif op is BRANCH:
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print()
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for i, a in enumerate(av[1]):
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if i:
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print(level*" " + "OR")
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a.dump(level+1)
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elif op is GROUPREF_EXISTS:
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condgroup, item_yes, item_no = av
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print('', condgroup)
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item_yes.dump(level+1)
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if item_no:
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print(level*" " + "ELSE")
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item_no.dump(level+1)
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elif isinstance(av, seqtypes):
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nl = False
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for a in av:
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if isinstance(a, SubPattern):
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if not nl:
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print()
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a.dump(level+1)
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nl = True
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else:
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if not nl:
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print(' ', end='')
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print(a, end='')
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nl = False
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if not nl:
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print()
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else:
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print('', av)
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def __repr__(self):
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return repr(self.data)
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def __len__(self):
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return len(self.data)
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def __delitem__(self, index):
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del self.data[index]
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def __getitem__(self, index):
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if isinstance(index, slice):
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return SubPattern(self.state, self.data[index])
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return self.data[index]
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def __setitem__(self, index, code):
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self.data[index] = code
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def insert(self, index, code):
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self.data.insert(index, code)
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def append(self, code):
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self.data.append(code)
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def getwidth(self):
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# determine the width (min, max) for this subpattern
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if self.width is not None:
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return self.width
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lo = hi = 0
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for op, av in self.data:
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if op is BRANCH:
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i = MAXREPEAT - 1
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j = 0
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for av in av[1]:
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l, h = av.getwidth()
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i = min(i, l)
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j = max(j, h)
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lo = lo + i
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hi = hi + j
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elif op is ATOMIC_GROUP:
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i, j = av.getwidth()
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lo = lo + i
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hi = hi + j
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elif op is SUBPATTERN:
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i, j = av[-1].getwidth()
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lo = lo + i
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hi = hi + j
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elif op in _REPEATCODES:
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i, j = av[2].getwidth()
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lo = lo + i * av[0]
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hi = hi + j * av[1]
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elif op in _UNITCODES:
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lo = lo + 1
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hi = hi + 1
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elif op is GROUPREF:
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i, j = self.state.groupwidths[av]
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lo = lo + i
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hi = hi + j
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elif op is GROUPREF_EXISTS:
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i, j = av[1].getwidth()
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if av[2] is not None:
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l, h = av[2].getwidth()
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i = min(i, l)
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j = max(j, h)
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else:
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i = 0
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lo = lo + i
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hi = hi + j
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elif op is SUCCESS:
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break
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self.width = min(lo, MAXREPEAT - 1), min(hi, MAXREPEAT)
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return self.width
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class Tokenizer:
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def __init__(self, string):
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self.istext = isinstance(string, str)
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self.string = string
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if not self.istext:
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string = str(string, 'latin1')
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self.decoded_string = string
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self.index = 0
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self.next = None
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self.__next()
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def __next(self):
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index = self.index
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try:
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char = self.decoded_string[index]
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except IndexError:
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self.next = None
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return
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if char == "\\":
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index += 1
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try:
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char += self.decoded_string[index]
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except IndexError:
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raise error("bad escape (end of pattern)",
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self.string, len(self.string) - 1) from None
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self.index = index + 1
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self.next = char
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def match(self, char):
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if char == self.next:
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self.__next()
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return True
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return False
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def get(self):
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this = self.next
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self.__next()
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return this
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def getwhile(self, n, charset):
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result = ''
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for _ in range(n):
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c = self.next
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if c not in charset:
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break
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result += c
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self.__next()
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return result
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def getuntil(self, terminator, name):
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result = ''
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while True:
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c = self.next
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self.__next()
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if c is None:
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if not result:
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raise self.error("missing " + name)
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raise self.error("missing %s, unterminated name" % terminator,
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len(result))
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if c == terminator:
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if not result:
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raise self.error("missing " + name, 1)
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break
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result += c
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return result
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@property
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def pos(self):
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return self.index - len(self.next or '')
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def tell(self):
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return self.index - len(self.next or '')
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def seek(self, index):
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self.index = index
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self.__next()
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def error(self, msg, offset=0):
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if not self.istext:
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msg = msg.encode('ascii', 'backslashreplace').decode('ascii')
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return error(msg, self.string, self.tell() - offset)
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def checkgroupname(self, name, offset):
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if not (self.istext or name.isascii()):
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msg = "bad character in group name %a" % name
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raise self.error(msg, len(name) + offset)
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if not name.isidentifier():
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msg = "bad character in group name %r" % name
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raise self.error(msg, len(name) + offset)
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def _class_escape(source, escape):
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# handle escape code inside character class
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code = ESCAPES.get(escape)
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if code:
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return code
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code = CATEGORIES.get(escape)
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if code and code[0] is IN:
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return code
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try:
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c = escape[1:2]
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if c == "x":
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# hexadecimal escape (exactly two digits)
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escape += source.getwhile(2, HEXDIGITS)
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if len(escape) != 4:
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raise source.error("incomplete escape %s" % escape, len(escape))
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return LITERAL, int(escape[2:], 16)
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elif c == "u" and source.istext:
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# unicode escape (exactly four digits)
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escape += source.getwhile(4, HEXDIGITS)
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if len(escape) != 6:
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raise source.error("incomplete escape %s" % escape, len(escape))
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return LITERAL, int(escape[2:], 16)
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elif c == "U" and source.istext:
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# unicode escape (exactly eight digits)
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escape += source.getwhile(8, HEXDIGITS)
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if len(escape) != 10:
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raise source.error("incomplete escape %s" % escape, len(escape))
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c = int(escape[2:], 16)
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chr(c) # raise ValueError for invalid code
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return LITERAL, c
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elif c == "N" and source.istext:
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import unicodedata
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# named unicode escape e.g. \N{EM DASH}
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if not source.match('{'):
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raise source.error("missing {")
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charname = source.getuntil('}', 'character name')
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try:
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c = ord(unicodedata.lookup(charname))
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except (KeyError, TypeError):
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raise source.error("undefined character name %r" % charname,
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len(charname) + len(r'\N{}')) from None
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return LITERAL, c
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elif c in OCTDIGITS:
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# octal escape (up to three digits)
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escape += source.getwhile(2, OCTDIGITS)
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c = int(escape[1:], 8)
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if c > 0o377:
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raise source.error('octal escape value %s outside of '
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'range 0-0o377' % escape, len(escape))
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return LITERAL, c
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elif c in DIGITS:
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raise ValueError
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if len(escape) == 2:
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if c in ASCIILETTERS:
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raise source.error('bad escape %s' % escape, len(escape))
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return LITERAL, ord(escape[1])
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except ValueError:
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pass
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raise source.error("bad escape %s" % escape, len(escape))
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def _escape(source, escape, state):
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# handle escape code in expression
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code = CATEGORIES.get(escape)
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if code:
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return code
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code = ESCAPES.get(escape)
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if code:
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return code
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try:
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c = escape[1:2]
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if c == "x":
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# hexadecimal escape
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escape += source.getwhile(2, HEXDIGITS)
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if len(escape) != 4:
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raise source.error("incomplete escape %s" % escape, len(escape))
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return LITERAL, int(escape[2:], 16)
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elif c == "u" and source.istext:
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# unicode escape (exactly four digits)
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escape += source.getwhile(4, HEXDIGITS)
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if len(escape) != 6:
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raise source.error("incomplete escape %s" % escape, len(escape))
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return LITERAL, int(escape[2:], 16)
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elif c == "U" and source.istext:
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# unicode escape (exactly eight digits)
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escape += source.getwhile(8, HEXDIGITS)
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if len(escape) != 10:
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raise source.error("incomplete escape %s" % escape, len(escape))
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c = int(escape[2:], 16)
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chr(c) # raise ValueError for invalid code
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return LITERAL, c
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elif c == "N" and source.istext:
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import unicodedata
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# named unicode escape e.g. \N{EM DASH}
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if not source.match('{'):
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raise source.error("missing {")
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charname = source.getuntil('}', 'character name')
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try:
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c = ord(unicodedata.lookup(charname))
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except (KeyError, TypeError):
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raise source.error("undefined character name %r" % charname,
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len(charname) + len(r'\N{}')) from None
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return LITERAL, c
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elif c == "0":
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# octal escape
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escape += source.getwhile(2, OCTDIGITS)
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return LITERAL, int(escape[1:], 8)
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elif c in DIGITS:
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# octal escape *or* decimal group reference (sigh)
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if source.next in DIGITS:
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escape += source.get()
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if (escape[1] in OCTDIGITS and escape[2] in OCTDIGITS and
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source.next in OCTDIGITS):
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# got three octal digits; this is an octal escape
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escape += source.get()
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c = int(escape[1:], 8)
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if c > 0o377:
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raise source.error('octal escape value %s outside of '
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'range 0-0o377' % escape,
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len(escape))
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return LITERAL, c
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# not an octal escape, so this is a group reference
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group = int(escape[1:])
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if group < state.groups:
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if not state.checkgroup(group):
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raise source.error("cannot refer to an open group",
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len(escape))
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state.checklookbehindgroup(group, source)
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return GROUPREF, group
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raise source.error("invalid group reference %d" % group, len(escape) - 1)
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if len(escape) == 2:
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if c in ASCIILETTERS:
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raise source.error("bad escape %s" % escape, len(escape))
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return LITERAL, ord(escape[1])
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except ValueError:
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pass
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raise source.error("bad escape %s" % escape, len(escape))
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|
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def _uniq(items):
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return list(dict.fromkeys(items))
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def _parse_sub(source, state, verbose, nested):
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# parse an alternation: a|b|c
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items = []
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itemsappend = items.append
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sourcematch = source.match
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start = source.tell()
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while True:
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itemsappend(_parse(source, state, verbose, nested + 1,
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not nested and not items))
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if not sourcematch("|"):
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break
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if not nested:
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verbose = state.flags & SRE_FLAG_VERBOSE
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|
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if len(items) == 1:
|
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return items[0]
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|
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subpattern = SubPattern(state)
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|
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# check if all items share a common prefix
|
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while True:
|
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prefix = None
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for item in items:
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if not item:
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break
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if prefix is None:
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prefix = item[0]
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elif item[0] != prefix:
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break
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else:
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# all subitems start with a common "prefix".
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# move it out of the branch
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for item in items:
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del item[0]
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subpattern.append(prefix)
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continue # check next one
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break
|
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|
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# check if the branch can be replaced by a character set
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set = []
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for item in items:
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if len(item) != 1:
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break
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op, av = item[0]
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if op is LITERAL:
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set.append((op, av))
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elif op is IN and av[0][0] is not NEGATE:
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set.extend(av)
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else:
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break
|
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else:
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# we can store this as a character set instead of a
|
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# branch (the compiler may optimize this even more)
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subpattern.append((IN, _uniq(set)))
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return subpattern
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|
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subpattern.append((BRANCH, (None, items)))
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return subpattern
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|
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def _parse(source, state, verbose, nested, first=False):
|
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# parse a simple pattern
|
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subpattern = SubPattern(state)
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|
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# precompute constants into local variables
|
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subpatternappend = subpattern.append
|
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sourceget = source.get
|
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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("?"):
|
|
# Non-Greedy Match
|
|
subpattern[-1] = (MIN_REPEAT, (min, max, item))
|
|
elif sourcematch("+"):
|
|
# Possessive Match (Always Greedy)
|
|
subpattern[-1] = (POSSESSIVE_REPEAT, (min, max, item))
|
|
else:
|
|
# Greedy Match
|
|
subpattern[-1] = (MAX_REPEAT, (min, max, item))
|
|
|
|
elif this == ".":
|
|
subpatternappend((ANY, None))
|
|
|
|
elif this == "(":
|
|
start = source.tell() - 1
|
|
capture = True
|
|
atomic = False
|
|
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")
|
|
source.checkgroupname(name, 1)
|
|
elif sourcematch("="):
|
|
# named backreference
|
|
name = source.getuntil(")", "group name")
|
|
source.checkgroupname(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
|
|
capture = False
|
|
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 not (condname.isdecimal() and condname.isascii()):
|
|
source.checkgroupname(condname, 1)
|
|
condgroup = state.groupdict.get(condname)
|
|
if condgroup is None:
|
|
msg = "unknown group name %r" % condname
|
|
raise source.error(msg, len(condname) + 1)
|
|
else:
|
|
condgroup = int(condname)
|
|
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
|
|
)
|
|
if not (condname.isdecimal() and condname.isascii()):
|
|
import warnings
|
|
warnings.warn(
|
|
"bad character in group name %s at position %d" %
|
|
(repr(condname) if source.istext else ascii(condname),
|
|
source.tell() - len(condname) - 1),
|
|
DeprecationWarning, stacklevel=nested + 6
|
|
)
|
|
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 == ">":
|
|
# non-capturing, atomic group
|
|
capture = False
|
|
atomic = True
|
|
elif char in FLAGS or char == "-":
|
|
# flags
|
|
flags = _parse_flags(source, state, char)
|
|
if flags is None: # global flags
|
|
if not first or subpattern:
|
|
raise source.error('global flags not at the start '
|
|
'of the expression',
|
|
source.tell() - start)
|
|
verbose = state.flags & SRE_FLAG_VERBOSE
|
|
continue
|
|
|
|
add_flags, del_flags = flags
|
|
capture = False
|
|
else:
|
|
raise source.error("unknown extension ?" + char,
|
|
len(char) + 1)
|
|
|
|
# parse group contents
|
|
if capture:
|
|
try:
|
|
group = state.opengroup(name)
|
|
except error as err:
|
|
raise source.error(err.msg, len(name) + 1) from None
|
|
else:
|
|
group = 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)
|
|
if atomic:
|
|
assert group is None
|
|
subpatternappend((ATOMIC_GROUP, p))
|
|
else:
|
|
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
|
|
|
|
p = _parse_sub(source, state, flags & SRE_FLAG_VERBOSE, 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":
|
|
if not s.match("<"):
|
|
raise s.error("missing <")
|
|
name = s.getuntil(">", "group name")
|
|
if not (name.isdecimal() and name.isascii()):
|
|
s.checkgroupname(name, 1)
|
|
try:
|
|
index = groupindex[name]
|
|
except KeyError:
|
|
raise IndexError("unknown group name %r" % name) from None
|
|
else:
|
|
index = int(name)
|
|
if index >= MAXGROUPS:
|
|
raise s.error("invalid group reference %d" % index,
|
|
len(name) + 1)
|
|
if not (name.isdecimal() and name.isascii()):
|
|
import warnings
|
|
warnings.warn(
|
|
"bad character in group name %s at position %d" %
|
|
(repr(name) if s.istext else ascii(name),
|
|
s.tell() - len(name) - 1),
|
|
DeprecationWarning, stacklevel=5
|
|
)
|
|
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)) from None
|
|
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) from None
|
|
return empty.join(literals)
|