[PATCH v2 16/20] docs: kdoc_re: get rid of NestedMatch class

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

Now that everything was converted to CMatch, we can get rid of
the previous NestedMatch implementation.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 tools/lib/python/kdoc/kdoc_re.py | 202 -------------------------------
 1 file changed, 202 deletions(-)

diff --git a/tools/lib/python/kdoc/kdoc_re.py b/tools/lib/python/kdoc/kdoc_re.py
index ba601a4f5035..6f3ae28859ea 100644
--- a/tools/lib/python/kdoc/kdoc_re.py
+++ b/tools/lib/python/kdoc/kdoc_re.py
@@ -140,205 +140,3 @@ class KernRe:
         """
 
         return self.last_match.groups()
-
-
-#: Nested delimited pairs (brackets and parenthesis)
-DELIMITER_PAIRS = {
-    '{': '}',
-    '(': ')',
-    '[': ']',
-}
-
-#: compiled delimiters
-RE_DELIM = KernRe(r'[\{\}\[\]\(\)]')
-
-
-class NestedMatch:
-    """
-    Finding nested delimiters is hard with regular expressions. It is
-    even harder on Python with its normal re module, as there are several
-    advanced regular expressions that are missing.
-
-    This is the case of this pattern::
-
-            '\\bSTRUCT_GROUP(\\(((?:(?>[^)(]+)|(?1))*)\\))[^;]*;'
-
-    which is used to properly match open/close parentheses of the
-    string search STRUCT_GROUP(),
-
-    Add a class that counts pairs of delimiters, using it to match and
-    replace nested expressions.
-
-    The original approach was suggested by:
-
-        https://stackoverflow.com/questions/5454322/python-how-to-match-nested-parentheses-with-regex
-
-    Although I re-implemented it to make it more generic and match 3 types
-    of delimiters. The logic checks if delimiters are paired. If not, it
-    will ignore the search string.
-    """
-
-    # TODO: make NestedMatch handle multiple match groups
-    #
-    # Right now, regular expressions to match it are defined only up to
-    #       the start delimiter, e.g.:
-    #
-    #       \bSTRUCT_GROUP\(
-    #
-    # is similar to: STRUCT_GROUP\((.*)\)
-    # except that the content inside the match group is delimiter-aligned.
-    #
-    # The content inside parentheses is converted into a single replace
-    # group (e.g. r`\0').
-    #
-    # It would be nice to change such definition to support multiple
-    # match groups, allowing a regex equivalent to:
-    #
-    #   FOO\((.*), (.*), (.*)\)
-    #
-    # it is probably easier to define it not as a regular expression, but
-    # with some lexical definition like:
-    #
-    #   FOO(arg1, arg2, arg3)
-
-    def __init__(self, regex):
-        self.regex = KernRe(regex)
-
-    def _search(self, line):
-        """
-        Finds paired blocks for a regex that ends with a delimiter.
-
-        The suggestion of using finditer to match pairs came from:
-        https://stackoverflow.com/questions/5454322/python-how-to-match-nested-parentheses-with-regex
-        but I ended using a different implementation to align all three types
-        of delimiters and seek for an initial regular expression.
-
-        The algorithm seeks for open/close paired delimiters and places them
-        into a stack, yielding a start/stop position of each match when the
-        stack is zeroed.
-
-        The algorithm should work fine for properly paired lines, but will
-        silently ignore end delimiters that precede a start delimiter.
-        This should be OK for kernel-doc parser, as unaligned delimiters
-        would cause compilation errors. So, we don't need to raise exceptions
-        to cover such issues.
-        """
-
-        stack = []
-
-        for match_re in self.regex.finditer(line):
-            start = match_re.start()
-            offset = match_re.end()
-            string_char = None
-            escape = False
-
-            d = line[offset - 1]
-            if d not in DELIMITER_PAIRS:
-                continue
-
-            end = DELIMITER_PAIRS[d]
-            stack.append(end)
-
-            for match in RE_DELIM.finditer(line[offset:]):
-                pos = match.start() + offset
-
-                d = line[pos]
-
-                if escape:
-                    escape = False
-                    continue
-
-                if string_char:
-                    if d == '\\':
-                        escape = True
-                    elif d == string_char:
-                        string_char = None
-
-                    continue
-
-                if d in ('"', "'"):
-                    string_char = d
-                    continue
-
-                if d in DELIMITER_PAIRS:
-                    end = DELIMITER_PAIRS[d]
-
-                    stack.append(end)
-                    continue
-
-                # Does the end delimiter match what is expected?
-                if stack and d == stack[-1]:
-                    stack.pop()
-
-                    if not stack:
-                        yield start, offset, pos + 1
-                        break
-
-    def search(self, line):
-        """
-        This is similar to re.search:
-
-        It matches a regex that it is followed by a delimiter,
-        returning occurrences only if all delimiters are paired.
-        """
-
-        for t in self._search(line):
-
-            yield line[t[0]:t[2]]
-
-    def sub(self, sub, line, count=0):
-        """
-        This is similar to re.sub:
-
-        It matches a regex that it is followed by a delimiter,
-        replacing occurrences only if all delimiters are paired.
-
-        if the sub argument contains::
-
-            r'\0'
-
-        it will work just like re: it places there the matched paired data
-        with the delimiter stripped.
-
-        If count is different than zero, it will replace at most count
-        items.
-        """
-        out = ""
-
-        cur_pos = 0
-        n = 0
-
-        for start, end, pos in self._search(line):
-            out += line[cur_pos:start]
-
-            # Value, ignoring start/end delimiters
-            value = line[end:pos - 1]
-
-            # replaces \0 at the sub string, if \0 is used there
-            new_sub = sub
-            new_sub = new_sub.replace(r'\0', value)
-
-            out += new_sub
-
-            # Drop end ';' if any
-            if pos < len(line) and line[pos] == ';':
-                pos += 1
-
-            cur_pos = pos
-            n += 1
-
-            if count and count >= n:
-                break
-
-        # Append the remaining string
-        l = len(line)
-        out += line[cur_pos:l]
-
-        return out
-
-    def __repr__(self):
-        """
-        Returns a displayable version of the class init.
-        """
-
-        return f'NestedMatch("{self.regex.regex.pattern}")'
-- 
2.53.0