foo.lua

local snippets = require'snippets'
local U = require'snippets.utils'
local C = require'snippets.common'

local format = string.format
local insert = table.insert
local concat = table.concat

function time_delayed(count)
  vim.schedule(function()
    local api = vim.api
    local row, col = unpack(api.nvim_win_get_cursor(0))
    local L = api.nvim_buf_get_lines(0, row-1, row-1+count, false)
    api.nvim_buf_set_lines(0, row-1, row+count-1, false, {''})
    snippets.expand_at_cursor(concat(L, '\n'))
  end)
end

snippets.snippets = {
    test = (function()
      local S = [[$0# $1 items${|S.b == S.sb and time_delayed(1+(tonumber(S[1]) or 0))}]]
      S = U.into_snippet(S)
      local function bufnr()
        return tostring(vim.api.nvim_get_current_buf())
      end
      insert(S, C.structure_variable(false, 'sb', R.once(bufnr), -1, function() end))
      insert(S, C.structure_variable(false, 'b', bufnr, -1, function() end))
      insert(S, C.make_postorder_function_component(function(S)
        local L = {}
        for i = 1, tonumber(S[1]) or 0 do
          L[i] = format("%d. $%d", i, i)
        end
        return '\n'..concat(L, '\n')
      end))
      S = U.match_indentation(S)
      return S
    end)();
}