[WIP] Introduce support for generator feature handlers

.vscode/launch.json

@@ -1,4 +1,5 @@
 {
+    "version": "0.2.0",
     "configurations": [
         {
             "name": "pygls: Debug Server",

pygls/capabilities.py

@@ -14,13 +14,12 @@
 # See the License for the specific language governing permissions and      #
 # limitations under the License.                                           #
 ############################################################################
-from functools import reduce
-from typing import Any, Dict, List, Optional, Set, Union, TypeVar
 import logging
+from functools import reduce
+from typing import Any, Dict, List, Optional, Set, TypeVar, Union
 
 from lsprotocol import types
 
-
 logger = logging.getLogger(__name__)
 T = TypeVar("T")
 
@@ -62,6 +61,7 @@ def __init__(
         commands: List[str],
         text_document_sync_kind: types.TextDocumentSyncKind,
         notebook_document_sync: Optional[types.NotebookDocumentSyncOptions] = None,
+        position_encoding: types.PositionEncodingKind = types.PositionEncodingKind.Utf16,
     ):
         self.client_capabilities = client_capabilities
         self.features = features
@@ -71,12 +71,35 @@ def __init__(
         self.notebook_document_sync = notebook_document_sync
 
         self.server_cap = types.ServerCapabilities()
+        self.server_cap.position_encoding = position_encoding
 
     def _provider_options(self, feature: str, default: T) -> Optional[Union[T, Any]]:
         if feature in self.features:
             return self.feature_options.get(feature, default)
         return None
 
+    @classmethod
+    def choose_position_encoding(
+        cls, client_capabilities: types.ClientCapabilities
+    ) -> types.PositionEncodingKind:
+        server_encoding = types.PositionEncodingKind.Utf16
+
+        if (general := client_capabilities.general) is None:
+            return server_encoding
+
+        if (encodings := general.position_encodings) is None:
+            return server_encoding
+
+        # We match client preference where this an overlap between its and our supported encodings.
+        for client_encoding in encodings:
+            if client_encoding in _SUPPORTED_ENCODINGS:
+                server_encoding = client_encoding
+                return server_encoding
+
+        logger.warning(f"Unknown `PositionEncoding`s: {encodings}")
+
+        return server_encoding
+
     def _with_text_document_sync(self):
         open_close = (
             types.TEXT_DOCUMENT_DID_OPEN in self.features
@@ -415,27 +438,6 @@ def _with_inline_value_provider(self):
             self.server_cap.inline_value_provider = value
         return self
 
-    def _with_position_encodings(self):
-        self.server_cap.position_encoding = types.PositionEncodingKind.Utf16
-
-        general = self.client_capabilities.general
-        if general is None:
-            return self
-
-        encodings = general.position_encodings
-        if encodings is None:
-            return self
-
-        # We match client preference where this an overlap between its and our supported encodings.
-        for encoding in encodings:
-            if encoding in _SUPPORTED_ENCODINGS:
-                self.server_cap.position_encoding = encoding
-                return self
-
-        logger.warning(f"Unknown `PositionEncoding`s: {encodings}")
-
-        return self
-
     def _build(self):
         return self.server_cap
 
@@ -474,6 +476,5 @@ def build(self):
             ._with_workspace_capabilities()
             ._with_diagnostic_provider()
             ._with_inline_value_provider()
-            ._with_position_encodings()
             ._build()
         )

pygls/protocol/__init__.py

@@ -1,7 +1,6 @@
 import json
-from typing import Any
-
 from collections import namedtuple
+from typing import Any
 
 from lsprotocol import converters
 
@@ -12,7 +11,6 @@
     JsonRPCResponseMessage,
 )
 from pygls.protocol.language_server import LanguageServerProtocol, lsp_method
-from pygls.protocol.lsp_meta import LSPMeta, call_user_feature
 
 
 def _dict_to_object(d: Any):
@@ -68,8 +66,6 @@ def default_converter():
     "JsonRPCRequestMessage",
     "JsonRPCResponseMessage",
     "JsonRPCNotification",
-    "LSPMeta",
-    "call_user_feature",
     "_dict_to_object",
     "_params_field_structure_hook",
     "_result_field_structure_hook",