[codecs] Update _CharMap alias for mapping params

Author: donbarbos

stdlib/_codecs.pyi

@@ -1,6 +1,6 @@
 import codecs
 import sys
-from _typeshed import ReadableBuffer
+from _typeshed import ReadableBuffer, SupportsGetItem
 from collections.abc import Callable
 from typing import Literal, TypeAlias, final, overload, type_check_only
 
@@ -11,7 +11,8 @@ from typing import Literal, TypeAlias, final, overload, type_check_only
 class _EncodingMap:
     def size(self) -> int: ...
 
-_CharMap: TypeAlias = dict[int, int] | _EncodingMap
+_DecodeCharMap: TypeAlias = SupportsGetItem[int, str | int | None] | _EncodingMap
+_EncodeCharMap: TypeAlias = SupportsGetItem[int, bytes | int | None] | _EncodingMap
 _Handler: TypeAlias = Callable[[UnicodeError], tuple[str | bytes, int]]
 _SearchFunction: TypeAlias = Callable[[str], codecs.CodecInfo | None]
 
@@ -70,11 +71,13 @@ def decode(obj: str, encoding: Literal["hex", "hex_codec"], errors: str = "stric
 def decode(obj: ReadableBuffer, encoding: str = "utf-8", errors: str = "strict") -> str: ...
 
 def lookup(encoding: str, /) -> codecs.CodecInfo: ...
-def charmap_build(map: str, /) -> _CharMap: ...
+def charmap_build(map: str, /) -> dict[int, int] | _EncodingMap: ...
 def ascii_decode(data: ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
 def ascii_encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
-def charmap_decode(data: ReadableBuffer, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[str, int]: ...
-def charmap_encode(str: str, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[bytes, int]: ...
+def charmap_decode(
+    data: ReadableBuffer, errors: str | None = None, mapping: _DecodeCharMap | None = None, /
+) -> tuple[str, int]: ...
+def charmap_encode(str: str, errors: str | None = None, mapping: _EncodeCharMap | None = None, /) -> tuple[bytes, int]: ...
 
 # Docs say this accepts a bytes-like object, but in practice it also accepts str.
 def escape_decode(data: str | ReadableBuffer, errors: str | None = None, /) -> tuple[bytes, int]: ...

stdlib/encodings/charmap.pyi

@@ -1,33 +1,33 @@
 import codecs
-from _codecs import _CharMap
+from _codecs import _DecodeCharMap, _EncodeCharMap
 from _typeshed import ReadableBuffer
 
 class Codec(codecs.Codec):
     # At runtime, this is codecs.charmap_encode
     @staticmethod
-    def encode(str: str, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[bytes, int]: ...
+    def encode(str: str, errors: str | None = None, mapping: _EncodeCharMap | None = None, /) -> tuple[bytes, int]: ...
     # At runtime, this is codecs.charmap_decode
     @staticmethod
-    def decode(data: ReadableBuffer, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[str, int]: ...
+    def decode(data: ReadableBuffer, errors: str | None = None, mapping: _DecodeCharMap | None = None, /) -> tuple[str, int]: ...
 
 class IncrementalEncoder(codecs.IncrementalEncoder):
-    mapping: _CharMap | None
-    def __init__(self, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    mapping: _EncodeCharMap | None
+    def __init__(self, errors: str = "strict", mapping: _EncodeCharMap | None = None) -> None: ...
     def encode(self, input: str, final: bool = False) -> bytes: ...
 
 class IncrementalDecoder(codecs.IncrementalDecoder):
-    mapping: _CharMap | None
-    def __init__(self, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    mapping: _DecodeCharMap | None
+    def __init__(self, errors: str = "strict", mapping: _DecodeCharMap | None = None) -> None: ...
     def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
 
 class StreamWriter(Codec, codecs.StreamWriter):
-    mapping: _CharMap | None
-    def __init__(self, stream: codecs._WritableStream, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    mapping: _EncodeCharMap | None
+    def __init__(self, stream: codecs._WritableStream, errors: str = "strict", mapping: _EncodeCharMap | None = None) -> None: ...
     def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...  # type: ignore[override]
 
 class StreamReader(Codec, codecs.StreamReader):
-    mapping: _CharMap | None
-    def __init__(self, stream: codecs._ReadableStream, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    mapping: _DecodeCharMap | None
+    def __init__(self, stream: codecs._ReadableStream, errors: str = "strict", mapping: _DecodeCharMap | None = None) -> None: ...
     def decode(self, input: ReadableBuffer, errors: str = "strict") -> tuple[str, int]: ...  # type: ignore[override]
 
 def getregentry() -> codecs.CodecInfo: ...

stubs/webencodings/webencodings/custom.pyi

@@ -1,48 +1,48 @@
 import codecs
-from _codecs import _CharMap
+from _codecs import _DecodeCharMap, _EncodeCharMap, _EncodingMap
 from _typeshed import ReadableBuffer
-from typing import ClassVar, Final
+from typing import ClassVar, Final, Literal
 
 class Codec(codecs.Codec):
-    encoding_table: ClassVar[_CharMap | str | None]
-    decoding_table: ClassVar[_CharMap | str | None]
+    encoding_table: ClassVar[_EncodeCharMap | Literal[""] | None]
+    decoding_table: ClassVar[_DecodeCharMap | None]
     def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...
     def decode(self, input: bytes, errors: str = "strict") -> tuple[str, int]: ...
 
 class IncrementalEncoder(codecs.IncrementalEncoder):
-    encoding_table: ClassVar[_CharMap | str | None]
+    encoding_table: ClassVar[_EncodeCharMap | Literal[""] | None]
     def encode(self, input: str, final: bool = False) -> bytes: ...
 
 class IncrementalDecoder(codecs.IncrementalDecoder):
-    decoding_table: ClassVar[_CharMap | str | None]
+    decoding_table: ClassVar[_DecodeCharMap | None]
     def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
 
 class StreamWriter(Codec, codecs.StreamWriter): ...
 class StreamReader(Codec, codecs.StreamReader): ...
 
 user_decoding_table: Final[str]
-user_encoding_table: Final[_CharMap]
+user_encoding_table: Final[_EncodingMap]
 
 class UserCodec(Codec):
     decoding_table: ClassVar[str]
-    encoding_table: ClassVar[_CharMap]
+    encoding_table: ClassVar[_EncodeCharMap]
 
 class UserIncrementalEncoder(IncrementalEncoder):
-    encoding_table: ClassVar[_CharMap]
+    encoding_table: ClassVar[_EncodeCharMap]
 
 class UserIncrementalDecoder(IncrementalDecoder):
     decoding_table: ClassVar[str]
 
 user_codec_info: Final[codecs.CodecInfo]
 
 class ReplacementCodec(Codec):
-    decoding_table: ClassVar[str]
-    encoding_table: ClassVar[str]
+    decoding_table: ClassVar[_DecodeCharMap]
+    encoding_table: ClassVar[Literal[""]]
 
 class ReplacementIncrementalEncoder(IncrementalEncoder):
-    encoding_table: ClassVar[str]
+    encoding_table: ClassVar[Literal[""]]
 
 class ReplacementIncrementalDecoder(IncrementalDecoder):
-    decoding_table: ClassVar[str]
+    decoding_table: ClassVar[_DecodeCharMap]
 
 replacement_codec_info: Final[codecs.CodecInfo]