Re: [PATCH v5 11/36] qapi/common.py: Add indent manager

[Eduardo Habkost]

On Wed, Oct 07, 2020 at 02:08:33PM -0400, John Snow wrote:
> On 10/7/20 4:50 AM, Markus Armbruster wrote:
> > John Snow <jsnow@redhat.com> writes:
> > 
> > > Code style tools really dislike the use of global keywords, because it
> > > generally involves re-binding the name at runtime which can have strange
> > > effects depending on when and how that global name is referenced in
> > > other modules.
> > > 
> > > Make a little indent level manager instead.
> > > 
> > > Signed-off-by: John Snow <jsnow@redhat.com>
> > > Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> > > Reviewed-by: Cleber Rosa <crosa@redhat.com>
> > 
> > Intentation is a job for QAPIGen (and its subtypes).  But if this patch
> > is easier to achieve this series' goal, I don't mind.
> > 
> 
> I agree, but refactoring it properly is beyond my capacity right now.
> 
> This was the dumbest thing I could do to get pylint/mypy passing, which
> required the elimination (or suppression) of the global keyword.
> 
> Creating a stateful object was the fastest way from A to B.

An even dumber solution could be:

  indent_prefixes = []
  def push_indent(amount=4):
      """Add `amount` spaces to indentation prefix"""
      indent_prefixes.push(' '*amount)
  def pop_indent():
      """Revert the most recent push_indent() call"""
      indent_prefixes.pop()
  def genindent():
      """Return the current indentation prefix"""
      return ''.join(indent_prefixes)

No global keyword involved, and the only stateful object is a
dumb list.

-- 
Eduardo