Is it possible to delete part of a wildcard autocmd?

Question

If I put this

augroup AU_NAME
  autocmd!
  autocmd CursorMoved *.cpp,*.hs echo localtime()
augroup END

autocmd! AU_NAME CursorMoved *.cpp

in my vimrc, then open a file and enter :au AU_NAME, I see

--- Autocommands ---
AU_NAME  CursorMoved
    *.hs      echo localtime()

i.e. the autocmd! deletion action was only limited to *.cpp files, and it did counteract part of what the autocmd had targeted.

However, if the autocmd had been autocmd CursorMoved * echo localtime(), then the autocmd! for *.cpp has no effect.

I think the reason is clear: the * pattern in autocmd Event * ... does not expand to a comma separated (infinite) list of patterns from which autocmd! Group Event pattern can subtract the pattern.

However, is there a way to accomplish the task?

---

To avoid the XY problem, I'll give a hint of what my plan is.

With this plugin I've created, and which I'm still refining, I create a popup on CursorHold showing the whole line soft-wrapped on top of itself and some lines below (a mapping is provided to dismiss the popup). The user can pass, as an option, a string, say '*.cpp,*.html' which I use as the pattern for the autocmd CursorHold. The string defaults to '*' to target all files.

However, I also want to give users a way to request that the popup is shown as soon as the cursor moves, i.e. on CursorMoved (and still be given the same mapping to dismiss it). I would let the user pass another string to use as the pattern for this autocmd CursorMoved.

Now it's clear that for a given file type I don't want both CursorHold and CursorMoved to create a popup. Indeed, if the user gives the options this way,

let g:myplugin_opts = #{ onHold: '*', onMove: '*.cpp' }

to mean that they want to show the popup on CursorHold for every filetype except for C++ file, for which they want to show popup on CursorMoved, I can't just use those two strings for autocmd CursorHold and autocmd CursorMoved respectively, because in C++ files both autocmds would create a popup (and since I'm providing one nnoremap to close the popup by ID, it would close only one of the two popups).

Answer 1

"Comma" here is simply a shortcut for two autocmds invoking same list of commands: one for *.cpp and another for *.hs patterns.

Therefore, you can't. So delete "the star" and re-create autocmd anew. Or always trap "the star" and implement all pattern checking yourself.