X-Git-Url: https://git.openstreetmap.org./nominatim.git/blobdiff_plain/e37cfc64d2734bf67aedf44e57585d6bd5ff06af..d2853de47cac812193083f9b144a0bc818205dd6:/nominatim/tokenizer/base.py?ds=sidebyside

diff --git a/nominatim/tokenizer/base.py b/nominatim/tokenizer/base.py
index 6484ff6a..f0fd9dd0 100644
--- a/nominatim/tokenizer/base.py
+++ b/nominatim/tokenizer/base.py
@@ -5,17 +5,17 @@
 # Copyright (C) 2022 by the Nominatim developer community.
 # For a full list of authors see the git log.
 """
-Abstract class defintions for tokenizers. These base classes are here
+Abstract class definitions for tokenizers. These base classes are here
 mainly for documentation purposes.
 """
 from abc import ABC, abstractmethod
-from typing import List, Tuple, Dict, Any
+from typing import List, Tuple, Dict, Any, Optional, Iterable
 from pathlib import Path
 
-from typing_extensions import Protocol
-
 from nominatim.config import Configuration
+from nominatim.db.connection import Connection
 from nominatim.data.place_info import PlaceInfo
+from nominatim.typing import Protocol
 
 class AbstractAnalyzer(ABC):
     """ The analyzer provides the functions for analysing names and building
@@ -81,7 +81,8 @@ class AbstractAnalyzer(ABC):
 
 
     @abstractmethod
-    def update_special_phrases(self, phrases: List[Tuple[str, str, str, str]],
+    def update_special_phrases(self,
+                               phrases: Iterable[Tuple[str, str, str, str]],
                                should_replace: bool) -> None:
         """ Update the tokenizer's special phrase tokens from the given
             list of special phrases.
@@ -113,7 +114,7 @@ class AbstractAnalyzer(ABC):
             the search index.
 
             Arguments:
-                place: Place information retrived from the database.
+                place: Place information retrieved from the database.
 
             Returns:
                 A JSON-serialisable structure that will be handed into
@@ -141,7 +142,7 @@ class AbstractTokenizer(ABC):
 
               init_db: When set to False, then initialisation of database
                 tables should be skipped. This option is only required for
-                migration purposes and can be savely ignored by custom
+                migration purposes and can be safely ignored by custom
                 tokenizers.
 
             TODO: can we move the init_db parameter somewhere else?
@@ -187,7 +188,7 @@ class AbstractTokenizer(ABC):
 
 
     @abstractmethod
-    def check_database(self, config: Configuration) -> str:
+    def check_database(self, config: Configuration) -> Optional[str]:
         """ Check that the database is set up correctly and ready for being
             queried.
 
@@ -233,6 +234,13 @@ class AbstractTokenizer(ABC):
         """
 
 
+    @abstractmethod
+    def most_frequent_words(self, conn: Connection, num: int) -> List[str]:
+        """ Return a list of the `num` most frequent full words
+            in the database.
+        """
+
+
 class TokenizerModule(Protocol):
     """ Interface that must be exported by modules that implement their
         own tokenizer.