def _replace_complex(str_val):
"""
Replace the alternative or optional elements by a proper regular expression
:param str_val: the initial string
:return: the formatted expression
"""
result = str_val
matcher = RegexTemplate._alt_regex.search(result)
while matcher:
group_val = matcher.captures()[0]
if not StringUtils.check_form(group_val):
continue
if group_val.endswith('?'):
core = group_val[2:len(group_val) - 4]
if matcher.end() < len(result) and result[matcher.end()] == ' ':
result = result[:matcher.start()] + ("(?:" + core.replace("\\|", " \\|") + " )?") + result[matcher.end() + 1:]
elif matcher.end() >= len(result) and matcher.start() > 0 and result[matcher.start() - 1] == ' ':
result = result[:matcher.start() - 1] + ("(?: " + core.replace("\\|", " \\|") + ")?") + result[matcher.end():]
else:
result = result[:matcher.start()] + "(?:" + core + ")?" + result[matcher.end():]
else:
core = group_val[2:len(group_val) - 2]
result = result[:matcher.start()] + "(?:" + core + ")" + result[matcher.end():]
matcher = RegexTemplate._alt_regex.search(result)
return result
def find(self, str_val, max_results):
"""
Tries to find all occurrences of the template in the provided string. Stops
after the maximum number of results is reached.
"""
str_val = str_val.strip()
results = list()
for matcher in self._pattern.finditer(str_val):
if not StringUtils.is_delimited(str_val, matcher.start(), matcher.end()):
continue
match_result = MatchResult(matcher.start(), matcher.end())
for slot_key in self._slots.keys():
filled_value = matcher.group(self._slots[slot_key]).strip()
# quick-fix to handle some rare cases where the occurrence found
# by the regex leads to unbalanced parentheses or brackets.
# TODO: check whether this is a bug or not.
if not StringUtils.check_form(filled_value) and self.permutate_pattern():
return self.find(str_val, max_results)
match_result.add_pair(slot_key, filled_value)
results.append(match_result)
if len(results) >= max_results:
break
return results
def match(self, str_val):
"""
Tries to match the template against the provided string.
"""
input = str_val.strip()
matcher = self._pattern.fullmatch(input)
if matcher:
results = MatchResult(matcher.start(), matcher.end())
for slot_key in self._slots.keys():
filled_value = matcher.captures(self._slots[slot_key])[0]
if not StringUtils.check_form(filled_value) and self.permutate_pattern():
return self.match(str_val)
results.add_pair(slot_key, filled_value)
return results
return MatchResult(False)