Internationalisation of bzr cli

[Andrew Bennetts]

jbowtie at amathaine.com wrote:
> On Fri, Apr 29, 2011 at 12:16 PM, Martin Pool <mbp at canonical.com> wrote:
> > As soon as you feel you're sufficiently on the right track, please
> > propose your branch for merging and we can have a look in more detail.
> >  You don't have to have i18d everything, or even one whole command,
> > just enough to show the approach will basically work.
> >
> 
> One of the issues is that docstrings don't interact well with gettext
> - you need to monkey-patch inspect.getdoc to actually get those to
> display correctly. Which might be where you start to see performance
> issues.

Because getdoc strips the indentation of a multiline docstring, but we'd
be wrapping _() around the literal string including indentation?

It seems to me that, ideally, changing the indentation of a docstring
wouldn't affect the translations of that docstring.  i.e. these two
class definitions have effectively the same string, even though the
second one has more indentation on the non-initial lines:


class cmd_foo(Command):
    __doc__ = """Frobnicates the blatterwidget.
    
    This is a no-op when rotating widdershins.
    """


if have_frobnicator_module:
    class cmd_foo(Command):
        __doc__ = """Frobnicates the blatterwidget.
 
        This is a no-op when rotating widdershins.
        """


[We use explicit __doc__ assignments for docstrings that need to exist
always, regardless of whether python -OO is being used.  I'd expect that
other docstrings don't need to be translated, because they'll never be
seen by users.]

So I'd hope that whatever _() magic we use considers those two cases to
be the same string.  If it doesn't it wouldn't be very hard to manually
adjust any translations we already have for the new indentation as code
is refactored, but it would be annoying.

I think it'd be possible to cope with this without a performance hit and
without monkey-patching inspect.getdoc.  To avoid the performance hit we
just need to arrange for the dedenting to be delayed until we actually
need to look up a translation for the string, and I think if
inspect.getdoc is troublesome we can simply ignore it and write our own
variant, it's a pretty simple function (as your monkey-patch shows).

-Andrew.