Neovim异步缓冲等待

Question

I am working on a Neovim plugin that interacts with a REPL in a terminal buffer. I want to be able to send a command to the REPL, copy the response, and display it to the user somehow. Currently, the terminal buffer doesn't seem to refresh output until the current vimscript function terminates, so I can't have a single function that does, eg:

function! plugin#eval(str)
    call s:send_to_repl(str)
    echomsg s:get_response()
endfunction

as the get_response function is working with the terminal buffer before it gets updated.

Currently, I'm using neovim's job control, though if this can be accomplished in vanilla vim, all the better.

Here's the code I'm using to initialize the terminal:

function! s:start_buffer(height)
    set bufhidden=hide
    set noswapfile
    set buftype=nofile
    set hidden
    terminal! stack ghci --with-ghc intero
    let l:buffer_id = bufnr('%')
    let g:intero_job_id = b:terminal_job_id
endfunction

Here's how I'm sending the command to the REPL:

function! s:send(str)
    call jobsend(g:intero_job_id, add([a:str], ''))
endfunction

I've tried adding an edit command to refresh, but that doesn't seem to work in the REPL.

The code for communicating with the REPL is here . The code for managing the process is here .

Answer 1

In the :term buffer you can set up a TextChanged handler. Eg the following code sends the entire :term buffer contents to s:on_response :

autocmd TextChanged <buffer> call <SID>on_response(getline(1,'$'))

Figuring out which text is "new" since the previous TextChanged event will require some custom logic. The '[ and '] marks aren't correctly set in the :term buffer (I'm not sure this is feasible for nvim to do automatically, but I made a bug report ).

Note that TextChanged only fires if the user is in normal-mode (also immediately upon leaving insert-mode).

TextChangedI (notice the I at the end) should fire in insert-mode, but it doesn't work with :term , that's a bug .

---

Another approach is to user timers (see :help timer_start ). Here's a timer that calls s:on_reponse(timer_id) every second:

call timer_start(1000, '<SID>on_response', {'repeat':-1})

But this isn't ideal because you would need to keep a map of terminals and timer ids (or iterate through all :terminal buffers and check their contents).

---

I made a feature request for a jobattach() function which would allow attaching on_stdout handlers to existing jobs (whereas jobstart() only adds handlers to new jobs). This could then be used to attach to b:terminal_job_id of any :term buffer.