PEP 624: Minor updates (#1666)

Remove Python 3.9 from plan, because it is released already.
Rewrite objections section.

Author: methane

pep-0624.rst

@@ -122,23 +122,7 @@ Notes:
 Plan
 ====
 
-Python 3.9
-----------
-
-Add ``Py_DEPRECATED(3.3)`` to following APIs. This change is committed
-already [3]_. All other APIs have been marked ``Py_DEPRECATED(3.3)``
-already.
-
-* ``PyUnicode_EncodeDecimal()``
-* ``PyUnicode_TransformDecimalToASCII()``.
-
-Document all APIs as "will be removed in version 3.11".
-
-
-Python 3.11
------------
-
-These APIs are removed.
+Remove these APIs in Python 3.11. They have been deprecated already.
 
 * ``PyUnicode_Encode()``
 * ``PyUnicode_EncodeASCII()``
@@ -259,55 +243,35 @@ If we emit Python warning from ``PyUnicode_EncodeUTF8()``, warning
 filters and other threads may change the ``list`` and ``u`` can be
 a dangling reference after ``PyUnicode_EncodeUTF8()`` returned.
 
-Additionally, since we are not changing behavior but removing C APIs,
-runtime ``DeprecationWarning`` might not helpful for Python
-developers. We should warn to extension developers instead.
-
-
-Deprecate ``PyUnicode_Decode*`` APIs too
-----------------------------------------
 
-Not only remove ``PyUnicode_Encode*()`` APIs, but also deprecate
-following APIs too for symmetry and reducing number of APIs.
 
-* ``PyUnicode_DecodeASCII()``
-* ``PyUnicode_DecodeLatin1()``
-* ``PyUnicode_DecodeUTF7()``
-* ``PyUnicode_DecodeUTF8()``
-* ``PyUnicode_DecodeUTF16()``
-* ``PyUnicode_DecodeUTF32()``
-* ``PyUnicode_DecodeUnicodeEscape()``
-* ``PyUnicode_DecodeRawUnicodeEscape()``
-* ``PyUnicode_DecodeCharmap()``
-* ``PyUnicode_DecodeMBCS()``
+Discussions
+===========
 
-This idea is excluded from this PEP because of several reasons:
+* `Plan to remove Py_UNICODE APis except PEP 623
+  <https://mail.python.org/archives/list/python-dev@python.org/thread/S7KW2U6IGXZFBMGS6WSJB26NZIBW4OLE/#S7KW2U6IGXZFBMGS6WSJB26NZIBW4OLE>`_
+* `bpo-41123: Remove Py_UNICODE APIs except PEP 623: <https://bugs.python.org/issue41123>`_
 
-* We can not remove them anytime soon because they are part of stable
-  ABI.
 
-* ``PyUnicode_DecodeASCII()`` and ``PyUnicode_DecodeUTF8()`` are used
-  very widely. Deprecating them is not worth enough.
+Objections
+----------
 
-* Decoding from ``const char*`` is independent from Unicode
-  representation.
+* Removing these APIs removes ability to use codec without temporary Unicode.
 
-  * ``PyUnicode_Decode*()`` APIs are useful for applications and
-    extensions using UTF-8 or Python Unicode objects to store Unicode
-    string. But ``PyUnicode_Encode*()`` APIs are not useful for them.
+  * Codecs can not encode Unicode buffer directly without temporary Unicode
+    object since Python 3.3. All these APIs creates temporary Unicode object
+    for now. So removing them doesn't reduce any abilities.
 
-  * Python implementations using UTF-8 for Unicode internal
-    representation (e.g. PyPy and micropython) may not have encoder
-    with ``wchar_t*`` or UCS-4 input. But decoding from ``char*``
-    is very natural for them too.
+* Why not remove decoder APIs too?
 
+  * They are part of stable ABI.
 
-Discussions
-===========
+  * ``PyUnicode_DecodeASCII()`` and ``PyUnicode_DecodeUTF8()`` are used
+    very widely. Deprecating them is not worth enough.
 
-* `Plan to remove Py_UNICODE APis except PEP 623
-  <https://mail.python.org/archives/list/python-dev@python.org/thread/S7KW2U6IGXZFBMGS6WSJB26NZIBW4OLE/#S7KW2U6IGXZFBMGS6WSJB26NZIBW4OLE>`_
-* `bpo-41123: Remove Py_UNICODE APIs except PEP 623: <https://bugs.python.org/issue41123>`_
+  * Decoder APIs can decode from byte buffer directly, without creating
+    temporary bytes object. On the other hand, encoder APIs can not avoid
+    temporary Unicode object.
 
 
 References