Summary:
Purge needs to be able to see what directories the walker traversed, so
it can delete them if they are empty. Instead of having the walker call
match.traversedir (which it seems like a bizarre pattern to use the matcher as a
holder for a non-matching related function), let's have the walker return an
enum and have an option to return directories.
At the python layer we then translate this into match.traversedir calls, but we
can clean that up later.
Reviewed By: quark-zju
Differential Revision: D19543795
fbshipit-source-id: cc51c86c91799d3df2c65d25a7b6cfe810206d0a
Any native code (C/C++/Rust) that Mercurial (either core or extensions)
depends on should go here. Python code, or native code that depends on
Python code (e.g. #include <Python.h> or use cpython) is disallowed.
As we start to convert more of Mercurial into Rust, and write new paths
entrirely in native code, we'll want to limit our dependency on Python, which is
why this barrier exists.
See also hgext/extlib/README.md, mercurial/cext/README.mb.
How do I choose between lib and extlib (and cext)?
If your code is native and doesn't depend on Python (awesome!), it goes here.
Otherwise, put it in hgext/extlib (if it's only used by extensions) or
mercurial/cext (if it's used by extensions or core).