PEP 723: Mark as Provisional (#3505)

Co-authored-by: Carol Willing <carolcode@willingconsulting.com>
Co-authored-by: Brett Cannon <brett@python.org>
Co-authored-by: David Ellis <ducksual@gmail.com>

peps/pep-0723.rst

@@ -4,7 +4,7 @@ Author: Ofek Lev <ofekmeister@gmail.com>
 Sponsor: Adam Turner <python@quite.org.uk>
 PEP-Delegate: Brett Cannon <brett@python.org>
 Discussions-To: https://discuss.python.org/t/31151
-Status: Draft
+Status: Provisional
 Type: Standards Track
 Topic: Packaging
 Content-Type: text/x-rst
@@ -13,6 +13,7 @@ Post-History: `04-Aug-2023 <https://discuss.python.org/t/30979>`__,
               `06-Aug-2023 <https://discuss.python.org/t/31151>`__,
               `23-Aug-2023 <https://discuss.python.org/t/32149>`__,
 Replaces: 722
+Resolution: https://discuss.python.org/t/36763
 
 
 Abstract
@@ -101,14 +102,39 @@ This PEP defines a metadata comment block format loosely inspired [2]_ by
 
 __ https://docutils.sourceforge.io/docs/ref/rst/directives.html
 
-Any Python script may have top-level comment blocks that start with the line
+Any Python script may have top-level comment blocks that MUST start with the
-``# /// TYPE`` where ``TYPE`` determines how to process the content, and ends
+line ``# /// TYPE`` where ``TYPE`` determines how to process the content. That
-with the line ``# ///``. Every line between these two lines MUST be a comment
+is: a single ``#``, followed by a single space, followed by three forward
-starting with ``#``. If there are characters after the ``#`` then the first
+slashes, followed by a single space, followed by the type of metadata. Block
-character MUST be a space. The embedded content is formed by taking away the
+MUST end with the line ``# ///``. That is: a single ``#``, followed by a single
-first two characters of each line if the second character is a space, otherwise
+space, followed by three forward slashes. The ``TYPE`` MUST only consist of
-just the first character (which means the line consists of only a single
+ASCII letters, numbers and hyphens.
-``#``).
+
+Every line between these two lines (``# /// TYPE`` and ``# ///``) MUST be a
+comment starting with ``#``. If there are characters after the ``#`` then the
+first character MUST be a space. The embedded content is formed by taking away
+the first two characters of each line if the second character is a space,
+otherwise just the first character (which means the line consists of only a
+single ``#``).
+
+Precedence for an ending line ``# ///`` is given when the next line is not
+a valid embedded content line as described above. For example, the following
+is a single fully valid block:
+
+.. code:: python
+
+    # /// some-toml
+    # embedded-csharp = """
+    # /// <summary>
+    # /// text
+    # ///
+    # /// </summary>
+    # public class MyClass { }
+    # """
+    # ///
+
+A starting line MUST NOT be placed between another starting line and its ending
+line. In such cases tools MAY produce an error. Unclosed blocks MUST be ignored.
 
 When there are multiple comment blocks of the same ``TYPE`` defined, tools MUST
 produce an error.
@@ -219,7 +245,11 @@ higher.
        if len(matches) > 1:
            raise ValueError(f'Multiple {name} blocks found')
        elif len(matches) == 1:
-           return tomllib.loads(matches[0])
+           content = ''.join(
+               line[2:] if line.startswith('# ') else line[1:]
+               for line in matches[0].group('content').splitlines(keepends=True)
+           )
+           return tomllib.loads(content)
        else:
            return None
 
@@ -258,6 +288,23 @@ Note that this example used a library that preserves TOML formatting. This is
 not a requirement for editing by any means but rather is a "nice to have"
 feature.
 
+The following is an example of how to read a stream of arbitrary metadata
+blocks.
+
+.. code:: python
+
+   import re
+   from typing import Iterator
+
+   REGEX = r'(?m)^# /// (?P<type>[a-zA-Z0-9-]+)$\s(?P<content>(^#(| .*)$\s)+)^# ///$'
+
+   def stream(script: str) -> Iterator[tuple[str, str]]:
+       for match in re.finditer(REGEX, script):
+           yield match.group('type'), ''.join(
+               line[2:] if line.startswith('# ') else line[1:]
+               for line in match.group('content').splitlines(keepends=True)
+           )
+
 
 Backwards Compatibility
 =======================