bazarr/libs/rebulk/chain.py

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Chain patterns and handle repetiting capture group
"""
# pylint: disable=super-init-not-called
import itertools
from .loose import call, set_defaults
from .match import Match, Matches
from .pattern import Pattern, filter_match_kwargs
from .remodule import re
class _InvalidChainException(Exception):
"""
Internal exception raised when a chain is not valid
"""
pass
class Chain(Pattern):
"""
Definition of a pattern chain to search for.
"""
def __init__(self, rebulk, chain_breaker=None, **kwargs):
call(super(Chain, self).__init__, **kwargs)
self._kwargs = kwargs
self._match_kwargs = filter_match_kwargs(kwargs)
self._defaults = {}
self._regex_defaults = {}
self._string_defaults = {}
self._functional_defaults = {}
if callable(chain_breaker):
self.chain_breaker = chain_breaker
else:
self.chain_breaker = None
self.rebulk = rebulk
self.parts = []
def defaults(self, **kwargs):
"""
Define default keyword arguments for all patterns
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
self._defaults = kwargs
return self
def regex_defaults(self, **kwargs):
"""
Define default keyword arguments for functional patterns.
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
self._regex_defaults = kwargs
return self
def string_defaults(self, **kwargs):
"""
Define default keyword arguments for string patterns.
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
self._string_defaults = kwargs
return self
def functional_defaults(self, **kwargs):
"""
Define default keyword arguments for functional patterns.
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
self._functional_defaults = kwargs
return self
def chain(self):
"""
Add patterns chain, using configuration from this chain
:return:
:rtype:
"""
# pylint: disable=protected-access
chain = self.rebulk.chain(**self._kwargs)
chain._defaults = dict(self._defaults)
chain._regex_defaults = dict(self._regex_defaults)
chain._functional_defaults = dict(self._functional_defaults)
chain._string_defaults = dict(self._string_defaults)
return chain
def regex(self, *pattern, **kwargs):
"""
Add re pattern
:param pattern:
:type pattern:
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
set_defaults(self._kwargs, kwargs)
set_defaults(self._regex_defaults, kwargs)
set_defaults(self._defaults, kwargs)
pattern = self.rebulk.build_re(*pattern, **kwargs)
part = ChainPart(self, pattern)
self.parts.append(part)
return part
def functional(self, *pattern, **kwargs):
"""
Add functional pattern
:param pattern:
:type pattern:
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
set_defaults(self._kwargs, kwargs)
set_defaults(self._functional_defaults, kwargs)
set_defaults(self._defaults, kwargs)
pattern = self.rebulk.build_functional(*pattern, **kwargs)
part = ChainPart(self, pattern)
self.parts.append(part)
return part
def string(self, *pattern, **kwargs):
"""
Add string pattern
:param pattern:
:type pattern:
:param kwargs:
:type kwargs:
:return:
:rtype:
"""
set_defaults(self._kwargs, kwargs)
set_defaults(self._functional_defaults, kwargs)
set_defaults(self._defaults, kwargs)
pattern = self.rebulk.build_string(*pattern, **kwargs)
part = ChainPart(self, pattern)
self.parts.append(part)
return part
def close(self):
"""
Close chain builder to continue registering other pattern
:return:
:rtype:
"""
return self.rebulk
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
is_chain_start = True
for chain_part in self.parts:
try:
chain_part_matches, raw_chain_part_matches = Chain._match_chain_part(is_chain_start, chain_part,
chain_input_string,
context)
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 = dict()
for match_index, match in itertools.groupby(chain_part_matches,
lambda m: m.match_index):
grouped_matches_dict[match_index] = list(match)
grouped_raw_matches_dict = dict()
for match_index, raw_match in itertools.groupby(raw_chain_part_matches,
lambda m: m.match_index):
grouped_raw_matches_dict[match_index] = list(raw_match)
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)
except _InvalidChainException:
valid_chain = False
if current_chain_matches:
offset = current_chain_matches[0].raw_end
break
is_chain_start = False
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 _match_parent(self, match, yield_parent):
"""
Handle a parent match
:param match:
:type match:
:param yield_parent:
:type yield_parent:
:return:
:rtype:
"""
ret = super(Chain, self)._match_parent(match, yield_parent)
original_children = Matches(match.children)
original_end = match.end
while not ret and match.children:
last_pattern = match.children[-1].pattern
last_pattern_children = [child for child in match.children if child.pattern == last_pattern]
last_pattern_groups_iter = itertools.groupby(last_pattern_children, lambda child: child.match_index)
last_pattern_groups = {}
for index, matches in last_pattern_groups_iter:
last_pattern_groups[index] = list(matches)
for index in reversed(list(last_pattern_groups)):
last_matches = list(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(Chain, self)._match_parent(match, yield_parent)
if ret:
return True
match.children = original_children
match.end = original_end
return ret
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 _match_chain_part(is_chain_start, chain_part, chain_input_string, context):
chain_part_matches, raw_chain_part_matches = chain_part.pattern.matches(chain_input_string, context,
with_raw_matches=True)
chain_part_matches = Chain._truncate_chain_part_matches(is_chain_start, chain_part_matches, chain_part,
chain_input_string)
raw_chain_part_matches = Chain._truncate_chain_part_matches(is_chain_start, raw_chain_part_matches, chain_part,
chain_input_string)
Chain._validate_chain_part_matches(raw_chain_part_matches, chain_part)
return chain_part_matches, raw_chain_part_matches
@staticmethod
def _truncate_chain_part_matches(is_chain_start, chain_part_matches, chain_part, chain_input_string):
if not chain_part_matches:
return chain_part_matches
if not is_chain_start:
separator = chain_input_string[0:chain_part_matches[0].initiator.raw_start]
if separator:
return []
j = 1
for i in range(0, len(chain_part_matches) - 1):
separator = chain_input_string[chain_part_matches[i].initiator.raw_end:
chain_part_matches[i + 1].initiator.raw_start]
if separator:
break
j += 1
truncated = chain_part_matches[:j]
if chain_part.repeater_end is not None:
truncated = [m for m in truncated if m.match_index < chain_part.repeater_end]
return truncated
@staticmethod
def _validate_chain_part_matches(chain_part_matches, chain_part):
max_match_index = -1
if chain_part_matches:
max_match_index = max([m.match_index for m in chain_part_matches])
if max_match_index + 1 < chain_part.repeater_start:
raise _InvalidChainException
@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(object):
"""
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
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)