860 lines
29 KiB
Python
860 lines
29 KiB
Python
#
|
|
# 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 *
|
|
from _sre import MAXREPEAT
|
|
|
|
SPECIAL_CHARS = ".\\[{()*+?^$|"
|
|
REPEAT_CHARS = "*+?{"
|
|
|
|
DIGITS = set("0123456789")
|
|
|
|
OCTDIGITS = set("01234567")
|
|
HEXDIGITS = set("0123456789abcdefABCDEF")
|
|
|
|
WHITESPACE = set(" \t\n\r\v\f")
|
|
|
|
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,
|
|
}
|
|
|
|
class Pattern:
|
|
# master pattern object. keeps track of global attributes
|
|
def __init__(self):
|
|
self.flags = 0
|
|
self.open = []
|
|
self.groups = 1
|
|
self.groupdict = {}
|
|
def opengroup(self, name=None):
|
|
gid = self.groups
|
|
self.groups = gid + 1
|
|
if name is not None:
|
|
ogid = self.groupdict.get(name, None)
|
|
if ogid is not None:
|
|
raise error("redefinition of group name %s as group %d; "
|
|
"was group %d" % (repr(name), gid, ogid))
|
|
self.groupdict[name] = gid
|
|
self.open.append(gid)
|
|
return gid
|
|
def closegroup(self, gid):
|
|
self.open.remove(gid)
|
|
def checkgroup(self, gid):
|
|
return gid < self.groups and gid not in self.open
|
|
|
|
class SubPattern:
|
|
# a subpattern, in intermediate form
|
|
def __init__(self, pattern, data=None):
|
|
self.pattern = pattern
|
|
if data is None:
|
|
data = []
|
|
self.data = data
|
|
self.width = None
|
|
def dump(self, level=0):
|
|
nl = 1
|
|
seqtypes = (tuple, list)
|
|
for op, av in self.data:
|
|
print(level*" " + op, end=' '); nl = 0
|
|
if op == "in":
|
|
# member sublanguage
|
|
print(); nl = 1
|
|
for op, a in av:
|
|
print((level+1)*" " + op, a)
|
|
elif op == "branch":
|
|
print(); nl = 1
|
|
i = 0
|
|
for a in av[1]:
|
|
if i > 0:
|
|
print(level*" " + "or")
|
|
a.dump(level+1); nl = 1
|
|
i = i + 1
|
|
elif isinstance(av, seqtypes):
|
|
for a in av:
|
|
if isinstance(a, SubPattern):
|
|
if not nl: print()
|
|
a.dump(level+1); nl = 1
|
|
else:
|
|
print(a, end=' ') ; nl = 0
|
|
else:
|
|
print(av, end=' ') ; nl = 0
|
|
if not nl: print()
|
|
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.pattern, 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:
|
|
return self.width
|
|
lo = hi = 0
|
|
UNITCODES = (ANY, RANGE, IN, LITERAL, NOT_LITERAL, CATEGORY)
|
|
REPEATCODES = (MIN_REPEAT, MAX_REPEAT)
|
|
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 == 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
|
|
self.index = 0
|
|
self.__next()
|
|
def __next(self):
|
|
if self.index >= len(self.string):
|
|
self.next = None
|
|
return
|
|
char = self.string[self.index:self.index+1]
|
|
# Special case for the str8, since indexing returns a integer
|
|
# XXX This is only needed for test_bug_926075 in test_re.py
|
|
if char and not self.istext:
|
|
char = chr(char[0])
|
|
if char == "\\":
|
|
try:
|
|
c = self.string[self.index + 1]
|
|
except IndexError:
|
|
raise error("bogus escape (end of line)")
|
|
if not self.istext:
|
|
c = chr(c)
|
|
char = char + c
|
|
self.index = self.index + len(char)
|
|
self.next = char
|
|
def match(self, char, skip=1):
|
|
if char == self.next:
|
|
if skip:
|
|
self.__next()
|
|
return 1
|
|
return 0
|
|
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 tell(self):
|
|
return self.index, self.next
|
|
def seek(self, index):
|
|
self.index, self.next = index
|
|
|
|
# The following three functions are not used in this module anymore, but we keep
|
|
# them here (with DeprecationWarnings) for backwards compatibility.
|
|
|
|
def isident(char):
|
|
import warnings
|
|
warnings.warn('sre_parse.isident() will be removed in 3.5',
|
|
DeprecationWarning, stacklevel=2)
|
|
return "a" <= char <= "z" or "A" <= char <= "Z" or char == "_"
|
|
|
|
def isdigit(char):
|
|
import warnings
|
|
warnings.warn('sre_parse.isdigit() will be removed in 3.5',
|
|
DeprecationWarning, stacklevel=2)
|
|
return "0" <= char <= "9"
|
|
|
|
def isname(name):
|
|
import warnings
|
|
warnings.warn('sre_parse.isname() will be removed in 3.5',
|
|
DeprecationWarning, stacklevel=2)
|
|
# check that group name is a valid string
|
|
if not isident(name[0]):
|
|
return False
|
|
for char in name[1:]:
|
|
if not isident(char) and not isdigit(char):
|
|
return False
|
|
return True
|
|
|
|
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] == 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 ValueError
|
|
return LITERAL, int(escape[2:], 16) & 0xff
|
|
elif c == "u" and source.istext:
|
|
# unicode escape (exactly four digits)
|
|
escape += source.getwhile(4, HEXDIGITS)
|
|
if len(escape) != 6:
|
|
raise ValueError
|
|
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 ValueError
|
|
c = int(escape[2:], 16)
|
|
chr(c) # raise ValueError for invalid code
|
|
return LITERAL, c
|
|
elif c in OCTDIGITS:
|
|
# octal escape (up to three digits)
|
|
escape += source.getwhile(2, OCTDIGITS)
|
|
return LITERAL, int(escape[1:], 8) & 0xff
|
|
elif c in DIGITS:
|
|
raise ValueError
|
|
if len(escape) == 2:
|
|
return LITERAL, ord(escape[1])
|
|
except ValueError:
|
|
pass
|
|
raise error("bogus escape: %s" % repr(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 ValueError
|
|
return LITERAL, int(escape[2:], 16) & 0xff
|
|
elif c == "u" and source.istext:
|
|
# unicode escape (exactly four digits)
|
|
escape += source.getwhile(4, HEXDIGITS)
|
|
if len(escape) != 6:
|
|
raise ValueError
|
|
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 ValueError
|
|
c = int(escape[2:], 16)
|
|
chr(c) # raise ValueError for invalid code
|
|
return LITERAL, c
|
|
elif c == "0":
|
|
# octal escape
|
|
escape += source.getwhile(2, OCTDIGITS)
|
|
return LITERAL, int(escape[1:], 8) & 0xff
|
|
elif c in DIGITS:
|
|
# octal escape *or* decimal group reference (sigh)
|
|
if source.next in DIGITS:
|
|
escape = 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 = escape + source.get()
|
|
return LITERAL, int(escape[1:], 8) & 0xff
|
|
# not an octal escape, so this is a group reference
|
|
group = int(escape[1:])
|
|
if group < state.groups:
|
|
if not state.checkgroup(group):
|
|
raise error("cannot refer to open group")
|
|
return GROUPREF, group
|
|
raise ValueError
|
|
if len(escape) == 2:
|
|
return LITERAL, ord(escape[1])
|
|
except ValueError:
|
|
pass
|
|
raise error("bogus escape: %s" % repr(escape))
|
|
|
|
def _parse_sub(source, state, nested=1):
|
|
# parse an alternation: a|b|c
|
|
|
|
items = []
|
|
itemsappend = items.append
|
|
sourcematch = source.match
|
|
while 1:
|
|
itemsappend(_parse(source, state))
|
|
if sourcematch("|"):
|
|
continue
|
|
if not nested:
|
|
break
|
|
if not source.next or sourcematch(")", 0):
|
|
break
|
|
else:
|
|
raise error("pattern not properly closed")
|
|
|
|
if len(items) == 1:
|
|
return items[0]
|
|
|
|
subpattern = SubPattern(state)
|
|
subpatternappend = subpattern.append
|
|
|
|
# check if all items share a common prefix
|
|
while 1:
|
|
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]
|
|
subpatternappend(prefix)
|
|
continue # check next one
|
|
break
|
|
|
|
# check if the branch can be replaced by a character set
|
|
for item in items:
|
|
if len(item) != 1 or item[0][0] != LITERAL:
|
|
break
|
|
else:
|
|
# we can store this as a character set instead of a
|
|
# branch (the compiler may optimize this even more)
|
|
set = []
|
|
setappend = set.append
|
|
for item in items:
|
|
setappend(item[0])
|
|
subpatternappend((IN, set))
|
|
return subpattern
|
|
|
|
subpattern.append((BRANCH, (None, items)))
|
|
return subpattern
|
|
|
|
def _parse_sub_cond(source, state, condgroup):
|
|
item_yes = _parse(source, state)
|
|
if source.match("|"):
|
|
item_no = _parse(source, state)
|
|
if source.match("|"):
|
|
raise error("conditional backref with more than two branches")
|
|
else:
|
|
item_no = None
|
|
if source.next and not source.match(")", 0):
|
|
raise error("pattern not properly closed")
|
|
subpattern = SubPattern(state)
|
|
subpattern.append((GROUPREF_EXISTS, (condgroup, item_yes, item_no)))
|
|
return subpattern
|
|
|
|
_PATTERNENDERS = set("|)")
|
|
_ASSERTCHARS = set("=!<")
|
|
_LOOKBEHINDASSERTCHARS = set("=!")
|
|
_REPEATCODES = set([MIN_REPEAT, MAX_REPEAT])
|
|
|
|
def _parse(source, state):
|
|
# parse a simple pattern
|
|
subpattern = SubPattern(state)
|
|
|
|
# precompute constants into local variables
|
|
subpatternappend = subpattern.append
|
|
sourceget = source.get
|
|
sourcematch = source.match
|
|
_len = len
|
|
PATTERNENDERS = _PATTERNENDERS
|
|
ASSERTCHARS = _ASSERTCHARS
|
|
LOOKBEHINDASSERTCHARS = _LOOKBEHINDASSERTCHARS
|
|
REPEATCODES = _REPEATCODES
|
|
|
|
while 1:
|
|
|
|
if source.next in PATTERNENDERS:
|
|
break # end of subpattern
|
|
this = sourceget()
|
|
if this is None:
|
|
break # end of pattern
|
|
|
|
if state.flags & SRE_FLAG_VERBOSE:
|
|
# skip whitespace and comments
|
|
if this in WHITESPACE:
|
|
continue
|
|
if this == "#":
|
|
while 1:
|
|
this = sourceget()
|
|
if this in (None, "\n"):
|
|
break
|
|
continue
|
|
|
|
if this and this[0] not in SPECIAL_CHARS:
|
|
subpatternappend((LITERAL, ord(this)))
|
|
|
|
elif this == "[":
|
|
# character set
|
|
set = []
|
|
setappend = set.append
|
|
## if sourcematch(":"):
|
|
## pass # handle character classes
|
|
if sourcematch("^"):
|
|
setappend((NEGATE, None))
|
|
# check remaining characters
|
|
start = set[:]
|
|
while 1:
|
|
this = sourceget()
|
|
if this == "]" and set != start:
|
|
break
|
|
elif this and this[0] == "\\":
|
|
code1 = _class_escape(source, this)
|
|
elif this:
|
|
code1 = LITERAL, ord(this)
|
|
else:
|
|
raise error("unexpected end of regular expression")
|
|
if sourcematch("-"):
|
|
# potential range
|
|
this = sourceget()
|
|
if this == "]":
|
|
if code1[0] is IN:
|
|
code1 = code1[1][0]
|
|
setappend(code1)
|
|
setappend((LITERAL, ord("-")))
|
|
break
|
|
elif this:
|
|
if this[0] == "\\":
|
|
code2 = _class_escape(source, this)
|
|
else:
|
|
code2 = LITERAL, ord(this)
|
|
if code1[0] != LITERAL or code2[0] != LITERAL:
|
|
raise error("bad character range")
|
|
lo = code1[1]
|
|
hi = code2[1]
|
|
if hi < lo:
|
|
raise error("bad character range")
|
|
setappend((RANGE, (lo, hi)))
|
|
else:
|
|
raise error("unexpected end of regular expression")
|
|
else:
|
|
if code1[0] is IN:
|
|
code1 = code1[1][0]
|
|
setappend(code1)
|
|
|
|
# XXX: <fl> should move set optimization to compiler!
|
|
if _len(set)==1 and set[0][0] is LITERAL:
|
|
subpatternappend(set[0]) # optimization
|
|
elif _len(set)==2 and set[0][0] is NEGATE and set[1][0] is LITERAL:
|
|
subpatternappend((NOT_LITERAL, set[1][1])) # optimization
|
|
else:
|
|
# XXX: <fl> should add charmap optimization here
|
|
subpatternappend((IN, set))
|
|
|
|
elif this and this[0] in REPEAT_CHARS:
|
|
# repeat previous item
|
|
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
|
|
here = source.tell()
|
|
min, max = 0, MAXREPEAT
|
|
lo = hi = ""
|
|
while source.next in DIGITS:
|
|
lo = lo + source.get()
|
|
if sourcematch(","):
|
|
while source.next in DIGITS:
|
|
hi = 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 error("bad repeat interval")
|
|
else:
|
|
raise error("not supported")
|
|
# figure out which item to repeat
|
|
if subpattern:
|
|
item = subpattern[-1:]
|
|
else:
|
|
item = None
|
|
if not item or (_len(item) == 1 and item[0][0] == AT):
|
|
raise error("nothing to repeat")
|
|
if item[0][0] in REPEATCODES:
|
|
raise error("multiple repeat")
|
|
if sourcematch("?"):
|
|
subpattern[-1] = (MIN_REPEAT, (min, max, item))
|
|
else:
|
|
subpattern[-1] = (MAX_REPEAT, (min, max, item))
|
|
|
|
elif this == ".":
|
|
subpatternappend((ANY, None))
|
|
|
|
elif this == "(":
|
|
group = 1
|
|
name = None
|
|
condgroup = None
|
|
if sourcematch("?"):
|
|
group = 0
|
|
# options
|
|
if sourcematch("P"):
|
|
# python extensions
|
|
if sourcematch("<"):
|
|
# named group: skip forward to end of name
|
|
name = ""
|
|
while 1:
|
|
char = sourceget()
|
|
if char is None:
|
|
raise error("unterminated name")
|
|
if char == ">":
|
|
break
|
|
name = name + char
|
|
group = 1
|
|
if not name:
|
|
raise error("missing group name")
|
|
if not name.isidentifier():
|
|
raise error("bad character in group name %r" % name)
|
|
elif sourcematch("="):
|
|
# named backreference
|
|
name = ""
|
|
while 1:
|
|
char = sourceget()
|
|
if char is None:
|
|
raise error("unterminated name")
|
|
if char == ")":
|
|
break
|
|
name = name + char
|
|
if not name:
|
|
raise error("missing group name")
|
|
if not name.isidentifier():
|
|
raise error("bad character in backref group name "
|
|
"%r" % name)
|
|
gid = state.groupdict.get(name)
|
|
if gid is None:
|
|
msg = "unknown group name: {0!r}".format(name)
|
|
raise error(msg)
|
|
subpatternappend((GROUPREF, gid))
|
|
continue
|
|
else:
|
|
char = sourceget()
|
|
if char is None:
|
|
raise error("unexpected end of pattern")
|
|
raise error("unknown specifier: ?P%s" % char)
|
|
elif sourcematch(":"):
|
|
# non-capturing group
|
|
group = 2
|
|
elif sourcematch("#"):
|
|
# comment
|
|
while 1:
|
|
if source.next is None or source.next == ")":
|
|
break
|
|
sourceget()
|
|
if not sourcematch(")"):
|
|
raise error("unbalanced parenthesis")
|
|
continue
|
|
elif source.next in ASSERTCHARS:
|
|
# lookahead assertions
|
|
char = sourceget()
|
|
dir = 1
|
|
if char == "<":
|
|
if source.next not in LOOKBEHINDASSERTCHARS:
|
|
raise error("syntax error")
|
|
dir = -1 # lookbehind
|
|
char = sourceget()
|
|
p = _parse_sub(source, state)
|
|
if not sourcematch(")"):
|
|
raise error("unbalanced parenthesis")
|
|
if char == "=":
|
|
subpatternappend((ASSERT, (dir, p)))
|
|
else:
|
|
subpatternappend((ASSERT_NOT, (dir, p)))
|
|
continue
|
|
elif sourcematch("("):
|
|
# conditional backreference group
|
|
condname = ""
|
|
while 1:
|
|
char = sourceget()
|
|
if char is None:
|
|
raise error("unterminated name")
|
|
if char == ")":
|
|
break
|
|
condname = condname + char
|
|
group = 2
|
|
if not condname:
|
|
raise error("missing group name")
|
|
if condname.isidentifier():
|
|
condgroup = state.groupdict.get(condname)
|
|
if condgroup is None:
|
|
msg = "unknown group name: {0!r}".format(condname)
|
|
raise error(msg)
|
|
else:
|
|
try:
|
|
condgroup = int(condname)
|
|
except ValueError:
|
|
raise error("bad character in group name")
|
|
else:
|
|
# flags
|
|
if not source.next in FLAGS:
|
|
raise error("unexpected end of pattern")
|
|
while source.next in FLAGS:
|
|
state.flags = state.flags | FLAGS[sourceget()]
|
|
if group:
|
|
# parse group contents
|
|
if group == 2:
|
|
# anonymous group
|
|
group = None
|
|
else:
|
|
group = state.opengroup(name)
|
|
if condgroup:
|
|
p = _parse_sub_cond(source, state, condgroup)
|
|
else:
|
|
p = _parse_sub(source, state)
|
|
if not sourcematch(")"):
|
|
raise error("unbalanced parenthesis")
|
|
if group is not None:
|
|
state.closegroup(group)
|
|
subpatternappend((SUBPATTERN, (group, p)))
|
|
else:
|
|
while 1:
|
|
char = sourceget()
|
|
if char is None:
|
|
raise error("unexpected end of pattern")
|
|
if char == ")":
|
|
break
|
|
raise error("unknown extension")
|
|
|
|
elif this == "^":
|
|
subpatternappend((AT, AT_BEGINNING))
|
|
|
|
elif this == "$":
|
|
subpattern.append((AT, AT_END))
|
|
|
|
elif this and this[0] == "\\":
|
|
code = _escape(source, this, state)
|
|
subpatternappend(code)
|
|
|
|
else:
|
|
raise error("parser error")
|
|
|
|
return subpattern
|
|
|
|
def fix_flags(src, flags):
|
|
# Check and fix flags according to the type of pattern (str or bytes)
|
|
if isinstance(src, str):
|
|
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("can't use UNICODE flag with a bytes pattern")
|
|
return flags
|
|
|
|
def parse(str, flags=0, pattern=None):
|
|
# parse 're' pattern into list of (opcode, argument) tuples
|
|
|
|
source = Tokenizer(str)
|
|
|
|
if pattern is None:
|
|
pattern = Pattern()
|
|
pattern.flags = flags
|
|
pattern.str = str
|
|
|
|
p = _parse_sub(source, pattern, 0)
|
|
p.pattern.flags = fix_flags(str, p.pattern.flags)
|
|
|
|
tail = source.get()
|
|
if tail == ")":
|
|
raise error("unbalanced parenthesis")
|
|
elif tail:
|
|
raise error("bogus characters at end of regular expression")
|
|
|
|
if flags & SRE_FLAG_DEBUG:
|
|
p.dump()
|
|
|
|
if not (flags & SRE_FLAG_VERBOSE) and p.pattern.flags & SRE_FLAG_VERBOSE:
|
|
# the VERBOSE flag was switched on inside the pattern. to be
|
|
# on the safe side, we'll parse the whole thing again...
|
|
return parse(str, p.pattern.flags)
|
|
|
|
return p
|
|
|
|
def parse_template(source, pattern):
|
|
# 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):
|
|
if literal:
|
|
literals.append(''.join(literal))
|
|
del literal[:]
|
|
groups.append((len(literals), index))
|
|
literals.append(None)
|
|
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 s.match("<"):
|
|
while True:
|
|
char = sget()
|
|
if char is None:
|
|
raise error("unterminated group name")
|
|
if char == ">":
|
|
break
|
|
name += char
|
|
if not name:
|
|
raise error("missing group name")
|
|
try:
|
|
index = int(name)
|
|
if index < 0:
|
|
raise error("negative group number")
|
|
except ValueError:
|
|
if not name.isidentifier():
|
|
raise error("bad character in group name")
|
|
try:
|
|
index = pattern.groupindex[name]
|
|
except KeyError:
|
|
msg = "unknown group name: {0!r}".format(name)
|
|
raise IndexError(msg)
|
|
addgroup(index)
|
|
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
|
|
lappend(chr(int(this[1:], 8) & 0xff))
|
|
if not isoctal:
|
|
addgroup(int(this[1:]))
|
|
else:
|
|
try:
|
|
this = chr(ESCAPES[this][1])
|
|
except KeyError:
|
|
pass
|
|
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
|
|
sep = match.string[:0]
|
|
groups, literals = template
|
|
literals = literals[:]
|
|
try:
|
|
for index, group in groups:
|
|
literals[index] = s = g(group)
|
|
if s is None:
|
|
raise error("unmatched group")
|
|
except IndexError:
|
|
raise error("invalid group reference")
|
|
return sep.join(literals)
|