Issue #433028: Added support of modifier spans in regular expressions.
diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py
index 521e379..09f3be2 100644
--- a/Lib/sre_parse.py
+++ b/Lib/sre_parse.py
@@ -65,6 +65,12 @@
"u": SRE_FLAG_UNICODE,
}
+GLOBAL_FLAGS = (SRE_FLAG_ASCII | SRE_FLAG_LOCALE | SRE_FLAG_UNICODE |
+ SRE_FLAG_DEBUG | SRE_FLAG_TEMPLATE)
+
+class Verbose(Exception):
+ pass
+
class Pattern:
# master pattern object. keeps track of global attributes
def __init__(self):
@@ -184,7 +190,7 @@
lo = lo + i
hi = hi + j
elif op is SUBPATTERN:
- i, j = av[1].getwidth()
+ i, j = av[-1].getwidth()
lo = lo + i
hi = hi + j
elif op in _REPEATCODES:
@@ -395,7 +401,7 @@
pass
raise source.error("bad escape %s" % escape, len(escape))
-def _parse_sub(source, state, nested=True):
+def _parse_sub(source, state, verbose, nested=True):
# parse an alternation: a|b|c
items = []
@@ -403,7 +409,7 @@
sourcematch = source.match
start = source.tell()
while True:
- itemsappend(_parse(source, state))
+ itemsappend(_parse(source, state, verbose))
if not sourcematch("|"):
break
@@ -445,10 +451,10 @@
subpattern.append((BRANCH, (None, items)))
return subpattern
-def _parse_sub_cond(source, state, condgroup):
- item_yes = _parse(source, state)
+def _parse_sub_cond(source, state, condgroup, verbose):
+ item_yes = _parse(source, state, verbose)
if source.match("|"):
- item_no = _parse(source, state)
+ item_no = _parse(source, state, verbose)
if source.next == "|":
raise source.error("conditional backref with more than two branches")
else:
@@ -457,7 +463,7 @@
subpattern.append((GROUPREF_EXISTS, (condgroup, item_yes, item_no)))
return subpattern
-def _parse(source, state):
+def _parse(source, state, verbose):
# parse a simple pattern
subpattern = SubPattern(state)
@@ -467,7 +473,6 @@
sourcematch = source.match
_len = len
_ord = ord
- verbose = state.flags & SRE_FLAG_VERBOSE
while True:
@@ -621,6 +626,8 @@
group = True
name = None
condgroup = None
+ add_flags = 0
+ del_flags = 0
if sourcematch("?"):
# options
char = sourceget()
@@ -682,7 +689,7 @@
lookbehindgroups = state.lookbehindgroups
if lookbehindgroups is None:
state.lookbehindgroups = state.groups
- p = _parse_sub(source, state)
+ p = _parse_sub(source, state, verbose)
if dir < 0:
if lookbehindgroups is None:
state.lookbehindgroups = None
@@ -718,19 +725,13 @@
raise source.error("invalid group reference",
len(condname) + 1)
state.checklookbehindgroup(condgroup, source)
- elif char in FLAGS:
+ elif char in FLAGS or char == "-":
# flags
- while True:
- state.flags |= FLAGS[char]
- char = sourceget()
- if char is None:
- raise source.error("missing )")
- if char == ")":
- break
- if char not in FLAGS:
- raise source.error("unknown flag", len(char))
- verbose = state.flags & SRE_FLAG_VERBOSE
- continue
+ flags = _parse_flags(source, state, char)
+ if flags is None: # global flags
+ continue
+ add_flags, del_flags = flags
+ group = None
else:
raise source.error("unknown extension ?" + char,
len(char) + 1)
@@ -742,15 +743,17 @@
except error as err:
raise source.error(err.msg, len(name) + 1) from None
if condgroup:
- p = _parse_sub_cond(source, state, condgroup)
+ p = _parse_sub_cond(source, state, condgroup, verbose)
else:
- p = _parse_sub(source, state)
+ sub_verbose = ((verbose or (add_flags & SRE_FLAG_VERBOSE)) and
+ not (del_flags & SRE_FLAG_VERBOSE))
+ p = _parse_sub(source, state, sub_verbose)
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, p)))
+ subpatternappend((SUBPATTERN, (group, add_flags, del_flags, p)))
elif this == "^":
subpatternappend((AT, AT_BEGINNING))
@@ -763,6 +766,53 @@
return subpattern
+def _parse_flags(source, state, char):
+ sourceget = source.get
+ add_flags = 0
+ del_flags = 0
+ if char != "-":
+ while True:
+ add_flags |= FLAGS[char]
+ 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 == ")":
+ if ((add_flags & SRE_FLAG_VERBOSE) and
+ not (state.flags & SRE_FLAG_VERBOSE)):
+ raise Verbose
+ 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:
+ del_flags |= FLAGS[char]
+ 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):
@@ -789,18 +839,22 @@
pattern.flags = flags
pattern.str = str
- p = _parse_sub(source, pattern, 0)
+ try:
+ p = _parse_sub(source, pattern, flags & SRE_FLAG_VERBOSE, False)
+ except Verbose:
+ # the VERBOSE flag was switched on inside the pattern. to be
+ # on the safe side, we'll parse the whole thing again...
+ pattern = Pattern()
+ pattern.flags = flags | SRE_FLAG_VERBOSE
+ pattern.str = str
+ p = _parse_sub(source, pattern, True, False)
+
p.pattern.flags = fix_flags(str, p.pattern.flags)
if source.next is not None:
assert source.next == ")"
raise source.error("unbalanced parenthesis")
- 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)
-
if flags & SRE_FLAG_DEBUG:
p.dump()