make (all) surrounding delimiters large

[ces42]

Is your feature request related to a problem? Please describe it.
Using \left and \right can be a bit of a chore. Especially if you start writing a formula with lots of delimiters and only notice halfway in that there is a "tall" expression in there.

Describe the solution you'd like
It would be quite helpful to have a function (and probably also a normal mode mapping) that finds all math delimiters surrounding the cursor and makes them \left/\right delimiters if they are not already. E.g.

\exp \left( \int_0^1 f(x) dx + G(1 + T[x - \frac{x_0}{2}| ] ) \right)

(| is supposed to be the cursor position) would become

\exp \left( \int_0^1 f(x) dx + G\left(1 + T\left[x - \frac{x_0}{2} \right] \right) \right)

The use case I have in mind is binding this to some key combination in insert mode which I could press after writing a fraction/sum/integral so that I don't have to worry about manual \left/\right again. Even better, I could integrate this into my snippets to make it 100% automatic.

Describe alternatives you've considered
Currently I can do $tsd$ but this will only change the innermost delimiter. It's also a toggle so I can't just have my snippets call it automatically.

[lervag]

Interesting suggestion. It should be possible. Let me play with it and see what I can do.

[lervag]

I've added a function now. You can test it by calling it directly or mapping it, e.g.:

nnoremap <f8> :<c-u>call vimtex#delim#toggle_modifier_all()<cr>

I may make a mapping or command interface for this, but it would be useful with some feedback first. And perhaps a suggestion of default map and/or command name.

[ces42]

Right now this is going into an infinite loop when I apply it in $a\left( b \right)$ with the cursor on the b.

[lervag]

Sorry, that should be fixed now.

[ces42]

Awesome, this is going into my snippets file right away.

Two remarks:

• The name seems confusing to me because this does not act as a toggle
• Right now it adds an item to the undo history even when nothing happens (which surprises me because I would thing that the only thing in the method that would make vim add to the undo history

The latter can be avoided by the following patch

diff --git a/autoload/vimtex/delim.vim b/autoload/vimtex/delim.vim
index 56e4702..5778f16 100644
--- a/autoload/vimtex/delim.vim
+++ b/autoload/vimtex/delim.vim
@@ -124,7 +124,6 @@ endfunction
 
 " }}}1
 function! vimtex#delim#toggle_modifier_all() abort " {{{1
-  call vimtex#util#undostore()
 
   " Use syntax highlights to detect region math region
   let l:ww = &whichwrap
@@ -139,6 +138,7 @@ function! vimtex#delim#toggle_modifier_all() abort " {{{1
   call vimtex#pos#set_cursor(l:cursor)
 
 
+  let l:undostore = v:false
   while v:true
     let [l:open, l:close] = vimtex#delim#get_surrounding('delim_modq_math')
     if empty(l:open) || vimtex#pos#val(l:open) <= l:startval
@@ -148,6 +148,11 @@ function! vimtex#delim#toggle_modifier_all() abort " {{{1
     call vimtex#pos#set_cursor(vimtex#pos#prev(l:open))
     if !empty(l:open.mod) | continue | endif
 
+    if !l:undostore
+      call vimtex#util#undostore()
+      let l:undostore = v:true
+    endif
+
     " Add close modifier
     let line = getline(l:close.lnum)
     let line = strpart(line, 0, l:close.cnum - 1)

[lervag]

The name seems confusing to me because this does not act as a toggle

Agreed. Do you have a suggestion? How about vimtex#delim#add_modifiers? Do you have an opinion on default mapping and/or command name, e.g. :VimtexDelimAddModifiers? Perhaps a mapping suffices?

Right now it adds an item to the undo history even when nothing happens (which surprises me because I would thing that the only thing in the method that would make vim add to the undo history

Thanks, fixed now.

[lervag]

I've implemented this fully now, but please, feel free to comment the naming and default map. I don't mind changing it if you have a better idea.