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.
# Test the config layer generated by environment variables
import os
from mercurial import (
encoding,
extensions,
rcutil,
ui as uimod,
util,
)
from mercurial.utils import procutil
testtmp = encoding.environ[b'TESTTMP']
# prepare hgrc files
def join(name):
return os.path.join(testtmp, name)
with open(join(b'sysrc'), 'wb') as f:
f.write(b'[ui]\neditor=e0\n[pager]\npager=p0\n')
with open(join(b'userrc'), 'wb') as f:
f.write(b'[ui]\neditor=e1')
# replace rcpath functions so they point to the files above
def systemrcpath():
return [join(b'sysrc')]
def userrcpath():
return [join(b'userrc')]
extensions.wrapfunction(rcutil, 'default_rc_resources', lambda orig: [])
rcutil.systemrcpath = systemrcpath
rcutil.userrcpath = userrcpath
# utility to print configs
def printconfigs(env):
encoding.environ = env
rcutil._rccomponents = None # reset cache
ui = uimod.ui.load()
for section, name, value in ui.walkconfig():
source = ui.configsource(section, name)
procutil.stdout.write(
b'%s.%s=%s # %s\n' % (section, name, value, util.pconvert(source))
)
procutil.stdout.write(b'\n')
# environment variable overrides
printconfigs({})
printconfigs({b'EDITOR': b'e2', b'PAGER': b'p2'})