Indentation, tabs, and spaces (was re: [PATCH] support: Implement TEST_COMPARE_STRING)

[Zack Weinberg <zackw at panix dot com>]

On Wed, Nov 7, 2018 at 6:55 AM Florian Weimer <fweimer@redhat.com> wrote:
>* Szabolcs Nagy:
>> On 07/11/18 11:36, Gabriel F. T. Gomes wrote:
>>> On Wed, 07 Nov 2018, Florian Weimer wrote:
>>>>
>>>> I wasn't aware that we have a policy to use tabs.  Most of my changes
>>>> involving new files do not use tabs. 8-/
>>>
>>> Oh, maybe we don't.  Now I feel embarrassed that I complained about it so
>>> many times.
>>
>> why is there an awkward mix of space and tab
>> indentation everywhere in the code then?
>
> It's the Emacs default.  I don't know about vim.
>
> Have we ever discussed changing it?

The Emacs default behavior (tab stops are fixed at 8 spaces apart,
indentation width is variable, indent with a mix of tabs and spaces)
plus the GNU code-formatting standard's 2-space indentation width
produces text that combines the worst properties of tab-only and
spaces-only indentation.  I'm also constantly getting it wrong,
especially since every other project I contribute to mandates
spaces-only indentation so that's what my global settings are.

I don't recall ever seeing it come up before, but I would support
either a change to spaces-only, or a change to "tabs for indentation,
spaces for alignment" (see https://www.emacswiki.org/emacs/SmartTabs
for more details and an emacs minor mode; I don't know if equivalent
automation exists for vim).

Spaces-only would be easier to migrate to incrementally.  Smart tabs
are abstractly better in some ways but I think we'd have to
machine-reformat the entire repository to get rid of all the existing
8-space tabs.