dirstate-tree: Add tree traversal/iteration
Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.
Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.
This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.
Differential Revision: https://phab.mercurial-scm.org/D10370
# Disable the $CAP wire protocol capability.
if test -z "$CAP"
then
echo "CAP environment variable not set."
fi
cat > notcapable-$CAP.py << EOF
from mercurial import extensions, localrepo
from mercurial.interfaces import repository
def extsetup(ui):
extensions.wrapfunction(repository.peer, 'capable', wrapcapable)
extensions.wrapfunction(localrepo.localrepository, 'peer', wrappeer)
def wrapcapable(orig, self, name, *args, **kwargs):
if name in b'$CAP'.split(b' '):
return False
return orig(self, name, *args, **kwargs)
def wrappeer(orig, self):
# Since we're disabling some newer features, we need to make sure local
# repos add in the legacy features again.
return localrepo.locallegacypeer(self)
EOF
echo '[extensions]' >> $HGRCPATH
echo "notcapable-$CAP = `pwd`/notcapable-$CAP.py" >> $HGRCPATH