[Two9A]

And I've been using vim exclusively for north of fifteen years with Tab replacement, never had a problem with the editor getting confused about what happens with spaces when I hit Tab.

Some detail about the corner cases you've run into would be great, if they're happening constantly I can see how it would be a bugbear.

[jampekka]

For example with vim (debian) defaults, if you happen to have a 2-space indented Python (the first two spaces are for HN formatting, the first if should start at zero indent):

  if True:
    # Two space indent

And continue to add another if block in that, the autoindent will give you four spaces:

  if True:
    # Two space indent
    if True:
        # Four space autoindent

And if you make a new line after the last row there and hit a backspace, it'll erase one space instead of four, giving an indentation of 3 (+2) spaces. And if you start a new line after that, you'll get an indentation of 8 spaces in total. Ending up with:

  if True:
    # Two space indent
    if True:
        # Four space autoindent
      # Hitting backspace gives this
          # Hitting a tab gives this

This is just a one case, but things like this tend to happen quite often when editing code. Even if it's been originally PEP-8 indented. Usually it's not what the Tab does, but what the Backspace or Autoindent does. I'm not exactly sure what exact Tab/Backspace/Autoindent rules underlie the behavior, but I can imagine there having to be quite a bit of hackery to support soft-tabs.

For me this kind of Tab/Autoindent/Backspace confusion is frequent enough that I'd be very surprised if others don't find themselves having to manually fix the number of spaces every now and then. And when watching over the shoulder I see others too occasionally having to micromanage space-indents (or accidentally ending up with three space indented blocks etc), also with other editors than vim.

[arp242]

This is because ftplugin/python.vim does:

  if !exists("g:python_recommended_style") || g:python_recommended_style != 0
    " As suggested by PEP8.
    setlocal expandtab tabstop=4 softtabstop=4 shiftwidth=4
  endif

So if you use "set sw=2" then it leaves tabstop and softtabstop at 4.

You can set that g:python_recommended_style to disable it.

Also sw=0 uses the tabstop value, and softtabstop=-1 uses the shiftwidth value.

I agree Vim's behaviour there is a bit annoying and confusing, but it doesn't really have anything to do with tabs vs. spaces. I strongly prefer tabs myself as well by the way.

Even when you DO use tabs Vim will use spaces if sw/ts/sts differ by the way. Try sw=2 and using >>, or sts=2 with noexpandtab.

[WorldMaker]

As with most things in vim, it is definitely manageable in settings such as tw=2 (tab width) and sts=2 (soft tab stop). This is why a lot of older Python files, in particular, are littered with vim modelines with settings like these.

The nice modern twist is .editorconfig files and the plugins that support them including for vim. You can use those to set such standard language-specific config concerns in a general way for an entire "workspace" for every editor that supports or has a plugin that supports .editorconfig.