Implementation of query analysis for the ICU tokenizer.
"""
from typing import Tuple, Dict, List, Optional, NamedTuple, Iterator, Any, cast
-from copy import copy
from collections import defaultdict
import dataclasses
import difflib
from nominatim.api.logging import log
from nominatim.api.search import query as qmod
from nominatim.api.search.query_analyzer_factory import AbstractQueryAnalyzer
+from nominatim.db.sqlalchemy_types import Json
DB_TO_TOKEN_TYPE = {
seq = difflib.SequenceMatcher(a=self.lookup_word, b=norm)
distance = 0
for tag, afrom, ato, bfrom, bto in seq.get_opcodes():
- if tag == 'delete' and (afrom == 0 or ato == len(self.lookup_word)):
+ if tag in ('delete', 'insert') and (afrom == 0 or ato == len(self.lookup_word)):
distance += 1
elif tag == 'replace':
distance += max((ato-afrom), (bto-bfrom))
penalty = 0.0
if row.type == 'w':
penalty = 0.3
+ elif row.type == 'W':
+ if len(row.word_token) == 1 and row.word_token == row.word:
+ penalty = 0.2 if row.word.isdigit() else 0.3
elif row.type == 'H':
penalty = sum(0.1 for c in row.word_token if c != ' ' and not c.isdigit())
if all(not c.isdigit() for c in row.word_token):
penalty += 0.2 * (len(row.word_token) - 1)
+ elif row.type == 'C':
+ if len(row.word_token) == 1:
+ penalty = 0.3
if row.info is None:
lookup_word = row.word
async def setup(self) -> None:
""" Set up static data structures needed for the analysis.
"""
- rules = await self.conn.get_property('tokenizer_import_normalisation')
- self.normalizer = Transliterator.createFromRules("normalization", rules)
- rules = await self.conn.get_property('tokenizer_import_transliteration')
- self.transliterator = Transliterator.createFromRules("transliteration", rules)
+ 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)
if 'word' not in self.conn.t.meta.tables:
sa.Table('word', self.conn.t.meta,
sa.Column('word_token', sa.Text, nullable=False),
sa.Column('type', sa.Text, nullable=False),
sa.Column('word', sa.Text),
- sa.Column('info', self.conn.t.types.Json))
+ sa.Column('info', Json))
async def analyze_query(self, phrases: List[qmod.Phrase]) -> qmod.QueryStruct:
"""
log().section('Analyze query (using ICU tokenizer)')
normalized = list(filter(lambda p: p.text,
- (qmod.Phrase(p.ptype, self.normalizer.transliterate(p.text))
+ (qmod.Phrase(p.ptype, self.normalize_text(p.text))
for p in phrases)))
query = qmod.QueryStruct(normalized)
log().var_dump('Normalized query', query.source)
if row.type == 'S':
if row.info['op'] in ('in', 'near'):
if trange.start == 0:
- query.add_token(trange, qmod.TokenType.CATEGORY, token)
+ query.add_token(trange, qmod.TokenType.NEAR_ITEM, token)
else:
query.add_token(trange, qmod.TokenType.QUALIFIER, token)
- if trange.start == 0 or trange.end == query.num_token_slots():
- token = copy(token)
- token.penalty += 0.1 * (query.num_token_slots())
- query.add_token(trange, qmod.TokenType.CATEGORY, token)
else:
query.add_token(trange, DB_TO_TOKEN_TYPE[row.type], token)
return query
+ def normalize_text(self, text: str) -> str:
+ """ Bring the given text into a normalized form. That is the
+ standardized form search will work with. All information removed
+ at this stage is inevitably lost.
+ """
+ return cast(str, self.normalizer.transliterate(text))
+
+
def split_query(self, query: qmod.QueryStruct) -> Tuple[QueryParts, WordDict]:
""" Transliterate the phrases and split them into tokens.
and (repl.ttype != qmod.TokenType.HOUSENUMBER
or len(tlist.tokens[0].lookup_word) > 4):
repl.add_penalty(0.39)
- elif tlist.ttype == qmod.TokenType.HOUSENUMBER:
+ elif tlist.ttype == qmod.TokenType.HOUSENUMBER \
+ and len(tlist.tokens[0].lookup_word) <= 3:
if any(c.isdigit() for c in tlist.tokens[0].lookup_word):
for repl in node.starting:
- if repl.end == tlist.end and repl.ttype != qmod.TokenType.HOUSENUMBER \
- and (repl.ttype != qmod.TokenType.HOUSENUMBER
- or len(tlist.tokens[0].lookup_word) <= 3):
+ if repl.end == tlist.end and repl.ttype != qmod.TokenType.HOUSENUMBER:
repl.add_penalty(0.5 - tlist.tokens[0].penalty)
elif tlist.ttype not in (qmod.TokenType.COUNTRY, qmod.TokenType.PARTIAL):
norm = parts[i].normalized
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