nvim/ftplugin/julia.lua

local ok_conform, conform = pcall(require, 'conform')
if ok_conform then
  conform.formatters = conform.formatters or {}
  conform.formatters_by_ft = conform.formatters_by_ft or {}

  conform.formatters_by_ft.julia = { 'juliaformatter' }

  vim.api.nvim_create_autocmd('BufWritePre', {
    buffer = 0,
    callback = function()
      if vim.api.nvim_buf_line_count(0) > 2000 then
        return
      end
      conform.format({ timeout_ms = 2000, lsp_fallback = false })
    end,
  })
end

local ok_toggleterm, toggleterm_terminal = pcall(require, 'toggleterm.terminal')
local Terminal = ok_toggleterm and toggleterm_terminal.Terminal or nil

if not vim.g.julia_repl_setup_done and Terminal then
  vim.g.julia_repl_setup_done = true

  local function get_startup_commands()
    return [[
ENV["JULIA_NOVERSIONS"] = "yes"
try
  using Revise
catch
end
println("\033[2J\033[H")
]]
  end

  local function new_julia_terminal()
    return Terminal:new({
      cmd = 'julia --banner=no',
      direction = 'vertical',
      size = 80,
      hidden = true,
      on_open = function(term)
        vim.defer_fn(function()
          term:send(get_startup_commands())
        end, 100)

        vim.api.nvim_buf_set_keymap(term.bufnr, 'n', 'q', '<cmd>close<CR>', { noremap = true, silent = true })
        vim.api.nvim_buf_set_keymap(term.bufnr, 't', '<Esc>', '<C-\\><C-n>', { noremap = true, silent = true })

        local win = term.window or vim.api.nvim_get_current_win()
        vim.api.nvim_set_option_value('signcolumn', 'no', { win = win })
        vim.api.nvim_set_option_value('number', false, { win = win })
        vim.api.nvim_set_option_value('relativenumber', false, { win = win })
      end,
      on_exit = function(_)
        vim.cmd('stopinsert')
      end,
    })
  end

  vim.__julia_repl_terminal = new_julia_terminal()

  vim.api.nvim_create_user_command('JuliaREPL', function()
    local julia = vim.__julia_repl_terminal
    if not julia then
      vim.__julia_repl_terminal = new_julia_terminal()
      julia = vim.__julia_repl_terminal
    end

    if julia:is_open() then
      julia:close()
    else
      julia:open()
      vim.cmd('wincmd p')
    end
  end, {})

  vim.keymap.set('n', '<leader>Rr', '<cmd>JuliaREPL<CR>', { noremap = true, silent = true, desc = 'Run/REPL: Toggle' })
end

local function send_to_julia(code)
  local julia_terminal = vim.__julia_repl_terminal
  if not julia_terminal then
    return
  end

  if not julia_terminal:is_open() then
    julia_terminal:open()
    vim.defer_fn(function()
      julia_terminal:send(code)
      vim.cmd('wincmd p')
    end, 200)
  else
    julia_terminal:send(code)
    vim.cmd('wincmd p')
  end
end

local function get_cell_content()
  local cur_line = vim.api.nvim_win_get_cursor(0)[1]
  local lines = vim.api.nvim_buf_get_lines(0, 0, -1, false)
  local start_line, end_line = cur_line, cur_line

  while start_line > 1 and not lines[start_line - 1]:match('^#%%') and not lines[start_line - 1]:match('^##') do
    start_line = start_line - 1
  end

  while end_line < #lines and not lines[end_line + 1]:match('^#%%') and not lines[end_line + 1]:match('^##') do
    end_line = end_line + 1
  end

  return table.concat(vim.api.nvim_buf_get_lines(0, start_line - 1, end_line, false), '\n')
end

local opts = { buffer = true, silent = true }

vim.keymap.set('n', '<leader>Rf', function()
  send_to_julia('using Revise\nincludet("' .. vim.fn.expand('%:p') .. '")\n')
end, vim.tbl_extend('force', opts, { desc = 'Run/REPL: Run file' }))

vim.keymap.set('n', '<leader>Rl', function()
  send_to_julia(vim.api.nvim_get_current_line() .. '\n')
end, vim.tbl_extend('force', opts, { desc = 'Run/REPL: Send line' }))

vim.keymap.set('n', '<leader>Rc', function()
  send_to_julia(get_cell_content() .. '\n')
end, vim.tbl_extend('force', opts, { desc = 'Run/REPL: Send cell' }))

vim.keymap.set('v', '<leader>Rs', function()
  local start_pos = vim.fn.getpos("'<")[2]
  local end_pos = vim.fn.getpos("'>")[2]
  local code = table.concat(vim.api.nvim_buf_get_lines(0, start_pos - 1, end_pos, false), '\n')
  send_to_julia(code .. '\n')
end, vim.tbl_extend('force', opts, { desc = 'Run/REPL: Send selection' }))

vim.keymap.set('n', '<leader>Ri', function()
  send_to_julia('\x03')
end, vim.tbl_extend('force', opts, { desc = 'Run/REPL: Interrupt' }))

vim.keymap.set('n', '<leader>jb', function()
  send_to_julia('using BenchmarkTools\n@btime ' .. vim.api.nvim_get_current_line() .. '\n')
end, vim.tbl_extend('force', opts, { desc = 'Julia: Benchmark line' }))

vim.keymap.set('n', '<leader>Rx', function()
  local julia = vim.__julia_repl_terminal
  if julia then
    pcall(function()
      julia:shutdown()
    end)
  end
  vim.__julia_repl_terminal = Terminal:new({
    cmd = 'julia --banner=no',
    direction = 'vertical',
    size = 80,
    hidden = true,
  })
end, vim.tbl_extend('force', opts, { desc = 'Run/REPL: Restart' }))

vim.g.julia_ftplugin_migrated = true