Merge pull request #3692 from lonvia/word-lookup-variants

[nominatim.git] / src / nominatim_db / tokenizer / token_analysis / generic.py

diff --git a/src/nominatim_db/tokenizer/token_analysis/generic.py b/src/nominatim_db/tokenizer/token_analysis/generic.py
index 4aa84de76ba8945fd18e412abb974dbce8cfe6a0..b01cebf75e78081fbd74a91966cfe3a3876da36a 100644 (file)
--- a/src/nominatim_db/tokenizer/token_analysis/generic.py
+++ b/src/nominatim_db/tokenizer/token_analysis/generic.py
@@ -2,20 +2,19 @@
 #
 # This file is part of Nominatim. (https://nominatim.org)
 #
-# Copyright (C) 2024 by the Nominatim developer community.
+# Copyright (C) 2025 by the Nominatim developer community.
 # For a full list of authors see the git log.
 """
 Generic processor for names that creates abbreviation variants.
 """
-from typing import Mapping, Dict, Any, Iterable, Iterator, Optional, List, cast
+from typing import Mapping, Dict, Any, Iterable, Optional, List, cast, Tuple
 import itertools
 
-import datrie
-
 from ...errors import UsageError
 from ...data.place_name import PlaceName
 from .config_variants import get_variant_config
 from .generic_mutation import MutationVariantGenerator
+from .simple_trie import SimpleTrie
 
 # Configuration section
 
@@ -25,8 +24,7 @@ def configure(rules: Mapping[str, Any], normalizer: Any, _: Any) -> Dict[str, An
     """
     config: Dict[str, Any] = {}
 
-    config['replacements'], config['chars'] = get_variant_config(rules.get('variants'),
-                                                                 normalizer)
+    config['replacements'], _ = get_variant_config(rules.get('variants'), normalizer)
     config['variant_only'] = rules.get('mode', '') == 'variant-only'
 
     # parse mutation rules
@@ -68,12 +66,8 @@ class GenericTokenAnalysis:
         self.variant_only = config['variant_only']
 
         # Set up datrie
-        if config['replacements']:
-            self.replacements = datrie.Trie(config['chars'])
-            for src, repllist in config['replacements']:
-                self.replacements[src] = repllist
-        else:
-            self.replacements = None
+        self.replacements: Optional[SimpleTrie[List[str]]] = \
+            SimpleTrie(config['replacements']) if config['replacements'] else None
 
         # set up mutation rules
         self.mutations = [MutationVariantGenerator(*cfg) for cfg in config['mutations']]
@@ -84,7 +78,7 @@ class GenericTokenAnalysis:
         """
         return cast(str, self.norm.transliterate(name.name)).strip()
 
-    def compute_variants(self, norm_name: str) -> List[str]:
+    def compute_variants(self, norm_name: str) -> Tuple[List[str], List[str]]:
         """ Compute the spelling variants for the given normalized name
             and transliterate the result.
         """
@@ -93,18 +87,20 @@ class GenericTokenAnalysis:
         for mutation in self.mutations:
             variants = mutation.generate(variants)
 
-        return [name for name in self._transliterate_unique_list(norm_name, variants) if name]
-
-    def _transliterate_unique_list(self, norm_name: str,
-                                   iterable: Iterable[str]) -> Iterator[Optional[str]]:
-        seen = set()
+        varset = set(map(str.strip, variants))
         if self.variant_only:
-            seen.add(norm_name)
+            varset.discard(norm_name)
+
+        trans = []
+        norm = []
+
+        for var in varset:
+            t = self.to_ascii.transliterate(var).strip()
+            if t:
+                trans.append(t)
+                norm.append(var)
 
-        for variant in map(str.strip, iterable):
-            if variant not in seen:
-                seen.add(variant)
-                yield self.to_ascii.transliterate(variant).strip()
+        return trans, norm
 
     def _generate_word_variants(self, norm_name: str) -> Iterable[str]:
         baseform = '^ ' + norm_name + ' ^'
@@ -116,10 +112,10 @@ class GenericTokenAnalysis:
             pos = 0
             force_space = False
             while pos < baselen:
-                full, repl = self.replacements.longest_prefix_item(baseform[pos:],
-                                                                   (None, None))
-                if full is not None:
-                    done = baseform[startpos:pos]
+                frm = pos
+                repl, pos = self.replacements.longest_prefix(baseform, pos)
+                if repl is not None:
+                    done = baseform[startpos:frm]
                     partials = [v + done + r
                                 for v, r in itertools.product(partials, repl)
                                 if not force_space or r.startswith(' ')]
@@ -128,11 +124,10 @@ class GenericTokenAnalysis:
                         # to be helpful. Only use the original term.
                         startpos = 0
                         break
-                    startpos = pos + len(full)
-                    if full[-1] == ' ':
-                        startpos -= 1
+                    if baseform[pos - 1] == ' ':
+                        pos -= 1
                         force_space = True
-                    pos = startpos
+                    startpos = pos
                 else:
                     pos += 1
                     force_space = False