templatekw: add new-style template expansion to {manifest}
The goal is to allow us to easily access to nested data. The dot operator
will be introduced later so we can write '{p1.files}' instead of
'{revset("p1()") % "{files}"}' for example.
In the example above, 'p1' needs to carry a mapping dict along with its
string representation. If it were a list or a dict, it could be wrapped
semi-transparently with the _hybrid class, but for non-list/dict types,
it would be difficult to proxy all necessary functions to underlying value
type because several core operations may conflict with the ones of the
underlying value:
- hash(value) should be different from hash(wrapped(value)), which means
dict[wrapped(value)] would be invalid
- 'value == wrapped(value)' would be false, breaks 'ifcontains'
- len(wrapped(value)) may be either len(value) or len(iter(wrapped(value)))
So the wrapper has no proxy functions and its scope designed to be minimal.
It's unwrapped at eval*() functions so we don't have to care for a wrapped
object unless it's really needed:
# most template functions just call evalfuncarg()
unwrapped_value = evalfuncarg(context, mapping, args[n])
# if wrapped value is needed, use evalrawexp()
maybe_wrapped_value = evalrawexp(context, mapping, args[n])
Another idea was to wrap every template variable with a tagging class, but
which seemed uneasy without a static type checker.
This patch updates {manifest} to a mappable as an example.
# commitextras.py
#
# Copyright 2013 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''adds a new flag extras to commit (ADVANCED)'''
from __future__ import absolute_import
import re
from mercurial.i18n import _
from mercurial import (
commands,
error,
extensions,
registrar,
)
cmdtable = {}
command = registrar.command(cmdtable)
testedwith = 'ships-with-hg-core'
usedinternally = {
'amend_source',
'branch',
'close',
'histedit_source',
'topic',
'rebase_source',
'intermediate-source',
'__touch-noise__',
'source',
'transplant_source',
}
def extsetup(ui):
entry = extensions.wrapcommand(commands.table, 'commit', _commit)
options = entry[1]
options.append(('', 'extra', [],
_('set a changeset\'s extra values'), _("KEY=VALUE")))
def _commit(orig, ui, repo, *pats, **opts):
origcommit = repo.commit
try:
def _wrappedcommit(*innerpats, **inneropts):
extras = opts.get('extra')
if extras:
for raw in extras:
if '=' not in raw:
msg = _("unable to parse '%s', should follow "
"KEY=VALUE format")
raise error.Abort(msg % raw)
k, v = raw.split('=', 1)
if not k:
msg = _("unable to parse '%s', keys can't be empty")
raise error.Abort(msg % raw)
if re.search('[^\w-]', k):
msg = _("keys can only contain ascii letters, digits,"
" '_' and '-'")
raise error.Abort(msg)
if k in usedinternally:
msg = _("key '%s' is used internally, can't be set "
"manually")
raise error.Abort(msg % k)
inneropts['extra'][k] = v
return origcommit(*innerpats, **inneropts)
# This __dict__ logic is needed because the normal
# extension.wrapfunction doesn't seem to work.
repo.__dict__['commit'] = _wrappedcommit
return orig(ui, repo, *pats, **opts)
finally:
del repo.__dict__['commit']