Adding surrounds for LaTeX

[benbrastmckie]

I would like to be able to surround a text object x with \textit{ }, and similarly for other LaTeX operations. I'm struggling to achieve this by changing the default config that is provided. Any help would be much appreciated.

[kylechui]

Hi there! You can try something like this:

require("nvim-surround").setup({
    surrounds = {
        ["x"] = {
            add = { "\\textit{", "}" },
            find = "\\textit%b{}",
            delete = "^(\\textit{)().-(})()$",
        },
    }
})

For an explanation on how/why this works, please see :h nvim-surround.config.surrounds. If there's anything that's unclear, please let me know! The find and delete keys are Lua patterns, where %b{} indicates matching a balanced set of curly braces. The weird parentheses in delete are Lua match groups, explained more in :h nvim-surround.config.get_selections().

Bonus: This might be of some interest to you if you're working with LaTeX commands a bit, as a generalization of the surround you're asking for.

[benbrastmckie]

Thanks so much! I've been working on switching to Lua, after which I'm going to make a new video series which will hopefully be a little more streamlined than the previous videos. As I'm sure you can tell, I'm new to Lua, but excited to keep learning, and want to help others coming from LaTeX (and with no knowledge of the terminal etc.) how to learn to use these great tools.

(A) I tried the code you included above, but with no luck. It does wrap text in the non-math-mode command \textbf{ }, but I can't get it to spit our \mathbf{ } in context such as:

$ \Sigma $ --> $ \mathit{\Sigma} $

\[ 

  \Sigma --> \mathtt{\Sigma}

\]

(B) One further question... If I want to wrap 'part of a line' with $ resulting in $ part of a line $, I have the following:

local M = {}

local config = require("nvim-surround.config")

require("nvim-surround").buffer_setup({
  surrounds = {
    ["$"] = {
      add = { "$ ", " $" },
      find = function()
        return M.get_selection({ motion = "a$" })
      end,
      delete = "^($)().-($)()$",
    },

return M

I'm not sure if the M is required, or if there is a better way to do this.

(C) Also, is there a way to insert \[ ... \] separated by lines as follows, reusing $ to trigger the surround:

\[

first math line
second math line

\]

I'm glad that you liked the series on LaTeX in NeoVim! If you had any suggestions for how I could improve the Lua config I'm working on, I'd be very curious to know. Unfortunately I'm still struggling to get the LSP to import from Zotero.bib in ~/texmf/bibtex/bib/ by including \bibliography{Zotero.bib} at the end of the document, but so it goes...

[kylechui]

A) That's a bit strange; I assume you mean bf as opposed to it and tt? I just tried it again and it seems to work on my end.
B) A few things:

• The local M stuff is actually only necessary on my end for the plugin; it's how I "export" my functions as a "module" for you to use. From your end, you only need the buffer_setup function and local config line, and M.get_selection should be config.get_selection.
• Unlike vim-surround, nvim-surround's default action on "undefined" characters is to treat the singular characters as a left/right pair, for surrounding and deleting. Thus you actually don't need to do any additional setup, and can just select text and do <S-s>$ out of the box (I took a look at your setup).

C) There is currently no way of "overloading" the behavior so the $ key performs multiple actions; one thing that you could do is to use a different key like e (for equation) instead.

As for the Zotero stuff; I unfortunately never got far enough in math to utilize a tool like Zotero for citations, so I don't know how to help with that. I changed majors to computer science after my second year 😅

I'll take a look at your config!

[kylechui]

I opened a PR on your config with a few comments; I hope you find it useful :)

[benbrastmckie]

(A) Yes, sorry, I have it set up for all the text functions I use like \texttt{} etc., and cut and paste the wrong ones. I still can't seem to get it to work in mathmode, but otherwise works great. I'll keep fussing with it and hopefully get it working.

(B)i Awesome glad to sort that out!

(B)ii The only reason I define something for $ is that I like spaces between the $ and the math I'm selecting. Not a big deal really since it is rare to use this surround anyhow, and autopairs gives me the extra spaces I'm looking for upon inserting new $ | $.

(C) Ok, that's no big deal. Just thought I'd check :)

I also made my way from math (undergrad) to logic (grad). Now starting to make my way into compsci a bit. We will see where it leads...

Thanks again for the help!

[benbrastmckie]

And regarding the PR... I messed up the merge so had to force push, but thanks so much. The changes were all made :)