How can I jump outside the scope of LaTeX delimiters?

Question

I want to define insert mode mappings that will jump outside the scope of any delimiter I'm in (forward/backward). Where "delimiter" is in the broad sense of LaTeX delimiters, so not only {},[],() but also $$, \{ \}, \left( \right) etc. Preferably I'd like to use <tab>/<S-tab> for this.

How can I do that using vimtex?

Example (▒ marks cursor place, each line corresponding to a use of the intended "forward" keymap)

$\left[ f_{k(▒x)}+1 \right]-2$
$\left[ f_{k(x)▒}+1 \right]-2$
$\left[ f_{k(x)}▒+1 \right]-2$
$\left[ f_{k(x)}+1 \right]▒-2$
$\left[ f_{k(x)}+1 \right]-2$▒

P.S I'm using neovim with LazyVim distro, so can utilize treesitter and lsp if needed, but my guess is that vimtex should suffice.

Answer 1

You can use VimTeX for this, but it does require that we use some of the api's that users generally don't know. Here's a Lua implementation that seems to work well:

vim.keymap.set("i", "<tab>", function()
  local delims = vim.fn["vimtex#delim#get_surrounding"]("all")
  local close = delims[2]

  if not vim.tbl_isempty(close) then
    vim.api.nvim_win_set_cursor(0, {
      close.lnum,
      close.cnum + vim.fn.strlen(close.match) - 1
    })
  end
end
{ desc = "jump forward out of delimiter scope" }
)

 vim.keymap.set("i", "<S-tab>", function()
        vim.cmd("norm! h")
        local delims = vim.fn["vimtex#delim#get_surrounding"]("all")
        local open = delims[1]

        if not vim.tbl_isempty(close) then
          vim.api.nvim_win_set_cursor(0, {
            open.lnum,
            open.cnum - 1,
          })
        end
      end, 
{ desc = "jump backward out of delimiter scope" }
) 

Answer 2

I would do:

inoremap <Tab> <Esc>/[\])}$]<CR>a

This mapping:

• Switch to Normal mode <Esc>
• Search for a closing brace (), }, ]) or a $ /[\])}$]
• Switch back to insert mode a

But it is not exactly the same of going one level up in nesting.

If you activate the builtin matchit plugin (runtime macros/matchit.vim) you could do:

imap <Tab> <Esc>]%a

It uses the ]% which is the equivalent of ]) but for all the 'braces' considered by matchit.

Remark: It doesn't support $ because for $ the open and closing brace characters are the same which make determining the level of nesting much more complex.