templates: add filter to reverse list
The filter supports only lists because for lists, it’s straightforward to
implement. Reversing text doesn’t seem very useful and is hard to implement.
Reversing the bytes would break multi-bytes encodings. Reversing the code
points would break characters consisting of multiple code points. Reversing
graphemes is non-trivial without using a library not included in the standard
library.
# Dummy extension to define a namespace containing revision names
from mercurial import namespaces
def reposetup(ui, repo):
names = {b'r%d' % rev: repo[rev].node() for rev in repo}
namemap = lambda r, name: names.get(name)
nodemap = lambda r, node: [b'r%d' % repo[node].rev()]
ns = namespaces.namespace(
b'revnames',
templatename=b'revname',
logname=b'revname',
listnames=lambda r: names.keys(),
namemap=namemap,
nodemap=nodemap,
)
repo.names.addnamespace(ns)