'Construct a new ``ChinkRule``.
:type tag_pattern: str
:param tag_pattern: This rule\'s tag pattern.  When
applied to a ``ChunkString``, this rule will
find any substring that matches this tag pattern and that
is contained in a chunk, and remove it from that chunk,
thus creating two new chunks.
:type descr: str
:param descr: A short description of the purpose and/or effect
of this rule.'

def __init__(self, tag_pattern, descr):

    self._pattern = tag_pattern
    regexp = re.compile((u'(?P<chink>%s)%s' % (tag_pattern2re_pattern(tag_pattern), ChunkString.IN_CHUNK_PATTERN)))
    RegexpChunkRule.__init__(self, regexp, u'}\\g<chink>{', descr)
