Implementation of query analysis for the ICU tokenizer.
"""
from typing import Tuple, Dict, List, Optional, Iterator, Any, cast
-from collections import defaultdict
import dataclasses
import difflib
import re
from ..logging import log
from . import query as qmod
from ..query_preprocessing.config import QueryConfig
+from ..query_preprocessing.base import QueryProcessingFunc
from .query_analyzer_factory import AbstractQueryAnalyzer
+from .postcode_parser import PostcodeParser
DB_TO_TOKEN_TYPE = {
}
-@dataclasses.dataclass
-class QueryPart:
- """ Normalized and transliterated form of a single term in the query.
-
- When the term came out of a split during the transliteration,
- the normalized string is the full word before transliteration.
- Check the subsequent break type to figure out if the word is
- continued.
-
- Penalty is the break penalty for the break following the token.
- """
- token: str
- normalized: str
- penalty: float
-
-
-QueryParts = List[QueryPart]
-WordDict = Dict[str, List[qmod.TokenRange]]
-
-
-def extract_words(terms: List[QueryPart], start: int, words: WordDict) -> None:
- """ Add all combinations of words in the terms list after the
- given position to the word list.
- """
- total = len(terms)
- base_penalty = PENALTY_IN_TOKEN_BREAK[qmod.BREAK_WORD]
- for first in range(start, total):
- word = terms[first].token
- penalty = base_penalty
- words[word].append(qmod.TokenRange(first, first + 1, penalty=penalty))
- for last in range(first + 1, min(first + 20, total)):
- word = ' '.join((word, terms[last].token))
- penalty += terms[last - 1].penalty
- words[word].append(qmod.TokenRange(first, last + 1, penalty=penalty))
-
-
@dataclasses.dataclass
class ICUToken(qmod.Token):
""" Specialised token for ICU tokenizer.
addr_count=max(1, addr_count))
-class ICUQueryAnalyzer(AbstractQueryAnalyzer):
- """ Converter for query strings into a tokenized query
- using the tokens created by a ICU tokenizer.
- """
- def __init__(self, conn: SearchConnection) -> None:
- self.conn = conn
-
- async def setup(self) -> None:
- """ Set up static data structures needed for the analysis.
- """
- async def _make_normalizer() -> Any:
- rules = await self.conn.get_property('tokenizer_import_normalisation')
- return Transliterator.createFromRules("normalization", rules)
-
- self.normalizer = await self.conn.get_cached_value('ICUTOK', 'normalizer',
- _make_normalizer)
-
- async def _make_transliterator() -> Any:
- rules = await self.conn.get_property('tokenizer_import_transliteration')
- return Transliterator.createFromRules("transliteration", rules)
-
- self.transliterator = await self.conn.get_cached_value('ICUTOK', 'transliterator',
- _make_transliterator)
-
- await self._setup_preprocessing()
-
- if 'word' not in self.conn.t.meta.tables:
- sa.Table('word', self.conn.t.meta,
- sa.Column('word_id', sa.Integer),
- sa.Column('word_token', sa.Text, nullable=False),
- sa.Column('type', sa.Text, nullable=False),
- sa.Column('word', sa.Text),
- sa.Column('info', Json))
+@dataclasses.dataclass
+class ICUAnalyzerConfig:
+ postcode_parser: PostcodeParser
+ normalizer: Transliterator
+ transliterator: Transliterator
+ preprocessors: List[QueryProcessingFunc]
- async def _setup_preprocessing(self) -> None:
- """ Load the rules for preprocessing and set up the handlers.
- """
+ @staticmethod
+ async def create(conn: SearchConnection) -> 'ICUAnalyzerConfig':
+ rules = await conn.get_property('tokenizer_import_normalisation')
+ normalizer = Transliterator.createFromRules("normalization", rules)
- rules = self.conn.config.load_sub_configuration('icu_tokenizer.yaml',
- config='TOKENIZER_CONFIG')
- preprocessing_rules = rules.get('query-preprocessing', [])
+ rules = await conn.get_property('tokenizer_import_transliteration')
+ transliterator = Transliterator.createFromRules("transliteration", rules)
- self.preprocessors = []
+ preprocessing_rules = conn.config.load_sub_configuration('icu_tokenizer.yaml',
+ config='TOKENIZER_CONFIG')\
+ .get('query-preprocessing', [])
+ preprocessors: List[QueryProcessingFunc] = []
for func in preprocessing_rules:
if 'step' not in func:
raise UsageError("Preprocessing rule is missing the 'step' attribute.")
if not isinstance(func['step'], str):
raise UsageError("'step' attribute must be a simple string.")
- module = self.conn.config.load_plugin_module(
+ module = conn.config.load_plugin_module(
func['step'], 'nominatim_api.query_preprocessing')
- self.preprocessors.append(
- module.create(QueryConfig(func).set_normalizer(self.normalizer)))
+ preprocessors.append(
+ module.create(QueryConfig(func).set_normalizer(normalizer)))
+
+ return ICUAnalyzerConfig(PostcodeParser(conn.config),
+ normalizer, transliterator, preprocessors)
+
+
+class ICUQueryAnalyzer(AbstractQueryAnalyzer):
+ """ Converter for query strings into a tokenized query
+ using the tokens created by a ICU tokenizer.
+ """
+ def __init__(self, conn: SearchConnection, config: ICUAnalyzerConfig) -> None:
+ self.conn = conn
+ self.postcode_parser = config.postcode_parser
+ self.normalizer = config.normalizer
+ self.transliterator = config.transliterator
+ self.preprocessors = config.preprocessors
async def analyze_query(self, phrases: List[qmod.Phrase]) -> qmod.QueryStruct:
""" Analyze the given list of phrases and return the
if not query.source:
return query
- parts, words = self.split_query(query)
- log().var_dump('Transliterated query', lambda: _dump_transliterated(query, parts))
+ self.split_query(query)
+ log().var_dump('Transliterated query', lambda: query.get_transliterated_query())
+ words = query.extract_words(base_penalty=PENALTY_IN_TOKEN_BREAK[qmod.BREAK_WORD])
for row in await self.lookup_in_db(list(words.keys())):
for trange in words[row.word_token]:
else:
query.add_token(trange, DB_TO_TOKEN_TYPE[row.type], token)
- self.add_extra_tokens(query, parts)
- self.rerank_tokens(query, parts)
+ self.add_extra_tokens(query)
+ for start, end, pc in self.postcode_parser.parse(query):
+ query.add_token(qmod.TokenRange(start, end),
+ qmod.TOKEN_POSTCODE,
+ ICUToken(penalty=0.1, token=0, count=1, addr_count=1,
+ lookup_word=pc, word_token=pc, info=None))
+ self.rerank_tokens(query)
log().table_dump('Word tokens', _dump_word_tokens(query))
"""
return cast(str, self.normalizer.transliterate(text)).strip('-: ')
- def split_query(self, query: qmod.QueryStruct) -> Tuple[QueryParts, WordDict]:
+ def split_query(self, query: qmod.QueryStruct) -> None:
""" Transliterate the phrases and split them into tokens.
-
- Returns the list of transliterated tokens together with their
- normalized form and a dictionary of words for lookup together
- with their position.
"""
- parts: QueryParts = []
- phrase_start = 0
- words: WordDict = defaultdict(list)
for phrase in query.source:
query.nodes[-1].ptype = phrase.ptype
phrase_split = re.split('([ :-])', phrase.text)
if trans:
for term in trans.split(' '):
if term:
- parts.append(QueryPart(term, word,
- PENALTY_IN_TOKEN_BREAK[qmod.BREAK_TOKEN]))
- query.add_node(qmod.BREAK_TOKEN, phrase.ptype)
- query.nodes[-1].btype = breakchar
- parts[-1].penalty = PENALTY_IN_TOKEN_BREAK[breakchar]
+ query.add_node(qmod.BREAK_TOKEN, phrase.ptype,
+ PENALTY_IN_TOKEN_BREAK[qmod.BREAK_TOKEN],
+ term, word)
+ query.nodes[-1].adjust_break(breakchar,
+ PENALTY_IN_TOKEN_BREAK[breakchar])
- extract_words(parts, phrase_start, words)
-
- phrase_start = len(parts)
- query.nodes[-1].btype = qmod.BREAK_END
-
- return parts, words
+ query.nodes[-1].adjust_break(qmod.BREAK_END, PENALTY_IN_TOKEN_BREAK[qmod.BREAK_END])
async def lookup_in_db(self, words: List[str]) -> 'sa.Result[Any]':
""" Return the token information from the database for the
given word tokens.
+
+ This function excludes postcode tokens
"""
t = self.conn.t.meta.tables['word']
- return await self.conn.execute(t.select().where(t.c.word_token.in_(words)))
+ return await self.conn.execute(t.select()
+ .where(t.c.word_token.in_(words))
+ .where(t.c.type != 'P'))
- def add_extra_tokens(self, query: qmod.QueryStruct, parts: QueryParts) -> None:
+ def add_extra_tokens(self, query: qmod.QueryStruct) -> None:
""" Add tokens to query that are not saved in the database.
"""
- for part, node, i in zip(parts, query.nodes, range(1000)):
- if len(part.token) <= 4 and part.token.isdigit()\
- and not node.has_tokens(i+1, qmod.TOKEN_HOUSENUMBER):
- query.add_token(qmod.TokenRange(i, i+1), qmod.TOKEN_HOUSENUMBER,
+ need_hnr = False
+ for i, node in enumerate(query.nodes):
+ is_full_token = node.btype not in (qmod.BREAK_TOKEN, qmod.BREAK_PART)
+ if need_hnr and is_full_token \
+ and len(node.term_normalized) <= 4 and node.term_normalized.isdigit():
+ query.add_token(qmod.TokenRange(i-1, i), qmod.TOKEN_HOUSENUMBER,
ICUToken(penalty=0.5, token=0,
- count=1, addr_count=1, lookup_word=part.token,
- word_token=part.token, info=None))
+ count=1, addr_count=1,
+ lookup_word=node.term_lookup,
+ word_token=node.term_lookup, info=None))
+
+ need_hnr = is_full_token and not node.has_tokens(i+1, qmod.TOKEN_HOUSENUMBER)
- def rerank_tokens(self, query: qmod.QueryStruct, parts: QueryParts) -> None:
+ def rerank_tokens(self, query: qmod.QueryStruct) -> None:
""" Add penalties to tokens that depend on presence of other token.
"""
for i, node, tlist in query.iter_token_lists():
if repl.end == tlist.end and repl.ttype != qmod.TOKEN_HOUSENUMBER:
repl.add_penalty(0.5 - tlist.tokens[0].penalty)
elif tlist.ttype not in (qmod.TOKEN_COUNTRY, qmod.TOKEN_PARTIAL):
- norm = parts[i].normalized
- for j in range(i + 1, tlist.end):
- if node.btype != qmod.BREAK_TOKEN:
- norm += ' ' + parts[j].normalized
+ norm = ' '.join(n.term_normalized for n in query.nodes[i + 1:tlist.end + 1]
+ if n.btype != qmod.BREAK_TOKEN)
+ if not norm:
+ # Can happen when the token only covers a partial term
+ norm = query.nodes[i + 1].term_normalized
for token in tlist.tokens:
cast(ICUToken, token).rematch(norm)
-def _dump_transliterated(query: qmod.QueryStruct, parts: QueryParts) -> str:
- out = query.nodes[0].btype
- for node, part in zip(query.nodes[1:], parts):
- out += part.token + node.btype
- return out
-
-
def _dump_word_tokens(query: qmod.QueryStruct) -> Iterator[List[Any]]:
- yield ['type', 'token', 'word_token', 'lookup_word', 'penalty', 'count', 'info']
- for node in query.nodes:
+ yield ['type', 'from', 'to', 'token', 'word_token', 'lookup_word', 'penalty', 'count', 'info']
+ for i, node in enumerate(query.nodes):
for tlist in node.starting:
for token in tlist.tokens:
t = cast(ICUToken, token)
- yield [tlist.ttype, t.token, t.word_token or '',
+ yield [tlist.ttype, str(i), str(tlist.end), t.token, t.word_token or '',
t.lookup_word or '', t.penalty, t.count, t.info]
""" Create and set up a new query analyzer for a database based
on the ICU tokenizer.
"""
- out = ICUQueryAnalyzer(conn)
- await out.setup()
+ async def _get_config() -> ICUAnalyzerConfig:
+ if 'word' not in conn.t.meta.tables:
+ sa.Table('word', conn.t.meta,
+ sa.Column('word_id', sa.Integer),
+ sa.Column('word_token', sa.Text, nullable=False),
+ sa.Column('type', sa.Text, nullable=False),
+ sa.Column('word', sa.Text),
+ sa.Column('info', Json))
+
+ return await ICUAnalyzerConfig.create(conn)
+
+ config = await conn.get_cached_value('ICUTOK', 'config', _get_config)
- return out
+ return ICUQueryAnalyzer(conn, config)