Moving matching lines to end of file in vim

In vim, we can move all matching lines to the end of the file using the global command (g).

Say we have a markdown file with some footenotes througout the file.

 ...
 [^angione2022using]: Angione, C., Silverman, E., et al. (2022), Using machine learning as a surrogate model for agent-based simulations.
 
 ...
 
 [^lamperti2018agent]: Lamperti, F., Roventini, A., et al. (2018), Agent-based model calibration using machine learning surrogates.

 ...

We can collect these footenotes at the end of the file with:

:g/^\[\^.*\]:/m $

This can be automated every time the file is saved by creating an autocommand. Here’s how to create one in NeoVim.

vim.api.nvim_create_autocmd("BufWritePre", {
    callback = function()
        vim.cmd(":g/^\\[^.*\\]:/m $<CR>")
    end,
    group = vim.api.nvim_create_augroup("markdown_format", { clear = true }),
})

Now, everytime the file is saved, any new footnotes added in the file are moved to the bottom.