In the private pathlib ABCs, replace `_WritablePath._write_info()` with
`_WritablePath._copy_from()`. This provides the target path object with
more control over the copying process, including support for querying and
setting metadata *before* the path is created.
Adjust `_ReadablePath.copy()` so that it forwards its keyword arguments to
`_WritablePath._copy_from()` of the target path object. This allows us to
remove the unimplemented *preserve_metadata* argument in the ABC method,
making it a `Path` exclusive.
Remove the *case_sensitive* argument from `_JoinablePath.full_match()` and
`_ReadablePath.glob()`. Using a non-native case sensitivity forces the use
of "case-pedantic" globbing, where we `iterdir()` even for non-wildcard
pattern segments. But it's hard to know when to enable this mode, as
case-sensitivity can vary by directory, so `_PathParser.normcase()` doesn't
always give the full picture. The `Path.glob()` implementation is forced to
make an educated guess, but we can avoid the issue in the ABCs by dropping
the *case_sensitive* argument.
(I probably shouldn't have added these arguments in `PurePath` and `Path`
in the first place!)
Also drop support for `_ReadablePath.glob(recurse_symlinks=False)`, which
makes recursive globbing much slower.
In `pathlib.types._JoinablePath.full_match()`, treat alternate path
separators in the path and pattern as if they were primary separators. e.g.
if the parser is `ntpath`, then `P(r'foo/bar\baz').full_match(r'*\*/*')` is
true.
In `pathlib.types._JoinablePath.with_name()`, retain any alternative path
separator preceding the old name, rather stripping and replacing it with a
primary separator. As a result, this method changes _only_ the name.
There used to be a meaningful distinction between these modules: `pathlib`
imported `pathlib._abc` but not `pathlib.types`. This is no longer the
case (neither module is imported), so we move the ABCs as follows:
- `pathlib._abc.JoinablePath` --> `pathlib.types._JoinablePath`
- `pathlib._abc.ReadablePath` --> `pathlib.types._ReadablePath`
- `pathlib._abc.WritablePath` --> `pathlib.types._WritablePath`
Add `pathlib.Path.info` attribute, which stores an object implementing the `pathlib.types.PathInfo` protocol (also new). The object supports querying the file type and internally caching `os.stat()` results. Path objects generated by `Path.iterdir()` are initialised with status information from `os.DirEntry` objects, which is gleaned from scanning the parent directory.
The `PathInfo` protocol has four methods: `exists()`, `is_dir()`, `is_file()` and `is_symlink()`.
