[mini.pairs] Filetype dependent indent on <CR> within parentheses?

[shyun3]

Contributing guidelines

• I have read CODE_OF_CONDUCT.md

Module(s)

mini.pairs

Question

When I press (, both parentheses are inserted e.g.:

(|)

where | is the cursor.

In this position, when pressing enter, the typical result would be:

(
    |
)

depending on your tab settings.

But in a c or cpp file, I'm seeing the following:

(
 |
 )

An indent of only one space is performed and the closing parenthesis is also indented for some reason.

Is there something with this plugin that is sensitive to filetype in this way? This only happens with (. Everything else seems to work as expected.

Here is my repro.lua (stolen from lazy.nvim, beware this will create .repro directory):

vim.env.LAZY_STDPATH = ".repro"
load(
  vim.fn.system(
    "curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua"
  )
)()

require("lazy.minit").repro({
  spec = {
    { "nvim-mini/mini.pairs", version = false, config = true },
  },
})

You can try this using nvim -u repro.lua test.lua and comparing it with nvim -u repro.lua test.c

[echasnovski]

An indent of only one space is performed and the closing parenthesis is also indented for some reason.

Is there something with this plugin that is sensitive to filetype in this way? This only happens with (. Everything else seems to work as expected.

There is nothing filetype dependent in 'mini.pairs' per se. But the <CR> implementation uses the approach that mimics the most robust approach that also respects filetype: pressing <CR> with 'mini.pairs' is basically the same as pressing <CR><C-o>O without 'mini.pairs'. Here <C-o> temporarily exits into Normal mode and O inserts an empty line above (usually properly indented; at least with default value of 'indentkeys').

I am afraid I can not help you with C filetype per se, but I can indeed reproduce this. The behavior with 'mini.pairs' is the same as <C-o>O without it. So my understanding is that is an intended default behavior which should be configurable with some options. I'd start looking in the direction of :h 'cindent', :h 'autoindent', :h 'smartindent', etc. The C filetype does indeed have a long history in VIM of being treated as special, I am afraid.

[shyun3]

Thank you, this was due to the default 'cinoptions'.

[echasnovski]

Thank you, this was due to the default 'cinoptions'.

If you don't mind, could you share a bit more for future users? Like what did you do (I presume, set 'cinoptions') and what result did it achieve? I'd rather mark that as an answer.

[shyun3]

Sorry, but I didn't exactly fix the issue. Upon further investigation, there doesn't seem to be an easy way to get the parentheses lined up in this scenario. cindent seems to treat parentheses specially compared to braces or brackets.

For this example:

(|)

no matter what cinoptions are used, pressing enter will always offset the next line by at least one e.g.:

(
 |)

(this is with nvim --clean).

[echasnovski]

no matter what cinoptions are used, pressing enter will always offset the next line by at least one e.g.:

Technically, this offset can be removed by vim.o.cindent = false. But it seems to block any possible value of 'cinoptions'. As I said, C is treated very special in Vim and Neovim :(

If you happen to find a solution, please let me know.