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bazarr/libs/rebulk/chain.py
2021-03-22 10:26:26 -04:00

380 lines
12 KiB
Python

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Chain patterns and handle repetiting capture group
"""
# pylint: disable=super-init-not-called
import itertools
from .builder import Builder
from .loose import call
from .match import Match, Matches
from .pattern import Pattern, filter_match_kwargs, BasePattern
from .remodule import re
class _InvalidChainException(Exception):
"""
Internal exception raised when a chain is not valid
"""
pass
class Chain(Pattern, Builder):
"""
Definition of a pattern chain to search for.
"""
def __init__(self, parent, chain_breaker=None, **kwargs):
Builder.__init__(self)
call(Pattern.__init__, self, **kwargs)
self._kwargs = kwargs
self._match_kwargs = filter_match_kwargs(kwargs)
if callable(chain_breaker):
self.chain_breaker = chain_breaker
else:
self.chain_breaker = None
self.parent = parent
self.parts = []
def pattern(self, *pattern):
"""
:param pattern:
:return:
"""
if not pattern:
raise ValueError("One pattern should be given to the chain")
if len(pattern) > 1:
raise ValueError("Only one pattern can be given to the chain")
part = ChainPart(self, pattern[0])
self.parts.append(part)
return part
def close(self):
"""
Deeply close the chain
:return: Rebulk instance
"""
parent = self.parent
while isinstance(parent, Chain):
parent = parent.parent
return parent
def _match(self, pattern, input_string, context=None):
# pylint: disable=too-many-locals,too-many-nested-blocks
chain_matches = []
chain_input_string = input_string
offset = 0
while offset < len(input_string):
chain_found = False
current_chain_matches = []
valid_chain = True
for chain_part in self.parts:
try:
chain_part_matches, raw_chain_part_matches = chain_part.matches(chain_input_string,
context,
with_raw_matches=True)
chain_found, chain_input_string, offset = \
self._to_next_chain_part(chain_part, chain_part_matches, raw_chain_part_matches, chain_found,
input_string, chain_input_string, offset, current_chain_matches)
except _InvalidChainException:
valid_chain = False
if current_chain_matches:
offset = current_chain_matches[0].raw_end
break
if not chain_found:
break
if current_chain_matches and valid_chain:
match = self._build_chain_match(current_chain_matches, input_string)
chain_matches.append(match)
return chain_matches
def _to_next_chain_part(self, chain_part, chain_part_matches, raw_chain_part_matches, chain_found,
input_string, chain_input_string, offset, current_chain_matches):
Chain._fix_matches_offset(chain_part_matches, input_string, offset)
Chain._fix_matches_offset(raw_chain_part_matches, input_string, offset)
if raw_chain_part_matches:
grouped_matches_dict = self._group_by_match_index(chain_part_matches)
grouped_raw_matches_dict = self._group_by_match_index(raw_chain_part_matches)
for match_index, grouped_raw_matches in grouped_raw_matches_dict.items():
chain_found = True
offset = grouped_raw_matches[-1].raw_end
chain_input_string = input_string[offset:]
if not chain_part.is_hidden:
grouped_matches = grouped_matches_dict.get(match_index, [])
if self._chain_breaker_eval(current_chain_matches + grouped_matches):
current_chain_matches.extend(grouped_matches)
return chain_found, chain_input_string, offset
def _process_match(self, match, match_index, child=False):
"""
Handle a match
:param match:
:type match:
:param match_index:
:type match_index:
:param child:
:type child:
:return:
:rtype:
"""
# pylint: disable=too-many-locals
ret = super()._process_match(match, match_index, child=child)
if ret:
return True
if match.children:
last_pattern = match.children[-1].pattern
last_pattern_groups = self._group_by_match_index(
[child_ for child_ in match.children if child_.pattern == last_pattern]
)
if last_pattern_groups:
original_children = Matches(match.children)
original_end = match.end
for index in reversed(list(last_pattern_groups)):
last_matches = last_pattern_groups[index]
for last_match in last_matches:
match.children.remove(last_match)
match.end = match.children[-1].end if match.children else match.start
ret = super()._process_match(match, match_index, child=child)
if ret:
return True
match.children = original_children
match.end = original_end
return False
def _build_chain_match(self, current_chain_matches, input_string):
start = None
end = None
for match in current_chain_matches:
if start is None or start > match.start:
start = match.start
if end is None or end < match.end:
end = match.end
match = call(Match, start, end, pattern=self, input_string=input_string, **self._match_kwargs)
for chain_match in current_chain_matches:
if chain_match.children:
for child in chain_match.children:
match.children.append(child)
if chain_match not in match.children:
match.children.append(chain_match)
chain_match.parent = match
return match
def _chain_breaker_eval(self, matches):
return not self.chain_breaker or not self.chain_breaker(Matches(matches))
@staticmethod
def _fix_matches_offset(chain_part_matches, input_string, offset):
for chain_part_match in chain_part_matches:
if chain_part_match.input_string != input_string:
chain_part_match.input_string = input_string
chain_part_match.end += offset
chain_part_match.start += offset
if chain_part_match.children:
Chain._fix_matches_offset(chain_part_match.children, input_string, offset)
@staticmethod
def _group_by_match_index(matches):
grouped_matches_dict = dict()
for match_index, match in itertools.groupby(matches, lambda m: m.match_index):
grouped_matches_dict[match_index] = list(match)
return grouped_matches_dict
@property
def match_options(self):
return {}
@property
def patterns(self):
return [self]
def __repr__(self):
defined = ""
if self.defined_at:
defined = "@%s" % (self.defined_at,)
return "<%s%s:%s>" % (self.__class__.__name__, defined, self.parts)
class ChainPart(BasePattern):
"""
Part of a pattern chain.
"""
def __init__(self, chain, pattern):
self._chain = chain
self.pattern = pattern
self.repeater_start = 1
self.repeater_end = 1
self._hidden = False
@property
def _is_chain_start(self):
return self._chain.parts[0] == self
def matches(self, input_string, context=None, with_raw_matches=False):
matches, raw_matches = self.pattern.matches(input_string, context=context, with_raw_matches=True)
matches = self._truncate_repeater(matches, input_string)
raw_matches = self._truncate_repeater(raw_matches, input_string)
self._validate_repeater(raw_matches)
if with_raw_matches:
return matches, raw_matches
return matches
def _truncate_repeater(self, matches, input_string):
if not matches:
return matches
if not self._is_chain_start:
separator = input_string[0:matches[0].initiator.raw_start]
if separator:
return []
j = 1
for i in range(0, len(matches) - 1):
separator = input_string[matches[i].initiator.raw_end:
matches[i + 1].initiator.raw_start]
if separator:
break
j += 1
truncated = matches[:j]
if self.repeater_end is not None:
truncated = [m for m in truncated if m.match_index < self.repeater_end]
return truncated
def _validate_repeater(self, matches):
max_match_index = -1
if matches:
max_match_index = max([m.match_index for m in matches])
if max_match_index + 1 < self.repeater_start:
raise _InvalidChainException
def chain(self):
"""
Add patterns chain, using configuration from this chain
:return:
:rtype:
"""
return self._chain.chain()
def hidden(self, hidden=True):
"""
Hide chain part results from global chain result
:param hidden:
:type hidden:
:return:
:rtype:
"""
self._hidden = hidden
return self
@property
def is_hidden(self):
"""
Check if the chain part is hidden
:return:
:rtype:
"""
return self._hidden
def regex(self, *pattern, **kwargs):
"""
Add re pattern
:param pattern:
:type pattern:
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
return self._chain.regex(*pattern, **kwargs)
def functional(self, *pattern, **kwargs):
"""
Add functional pattern
:param pattern:
:type pattern:
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
return self._chain.functional(*pattern, **kwargs)
def string(self, *pattern, **kwargs):
"""
Add string pattern
:param pattern:
:type pattern:
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
return self._chain.string(*pattern, **kwargs)
def close(self):
"""
Close the chain builder to continue registering other patterns
:return:
:rtype:
"""
return self._chain.close()
def repeater(self, value):
"""
Define the repeater of the current chain part.
:param value:
:type value:
:return:
:rtype:
"""
try:
value = int(value)
self.repeater_start = value
self.repeater_end = value
return self
except ValueError:
pass
if value == '+':
self.repeater_start = 1
self.repeater_end = None
if value == '*':
self.repeater_start = 0
self.repeater_end = None
elif value == '?':
self.repeater_start = 0
self.repeater_end = 1
else:
match = re.match(r'\{\s*(\d*)\s*,?\s*(\d*)\s*\}', value)
if match:
start = match.group(1)
end = match.group(2)
if start or end:
self.repeater_start = int(start) if start else 0
self.repeater_end = int(end) if end else None
return self
def __repr__(self):
return "%s({%s,%s})" % (self.pattern, self.repeater_start, self.repeater_end)