Force space and dot to start complition

.config/nvim/init.vim

@@ -91,6 +91,10 @@ function! s:check_back_space() abort
   let col = col('.') - 1
   return !col || getline('.')[col - 1]  =~# '\s'
 endfunction
+
+" Use <leader .> to trigger completion.
+inoremap <silent><expr> <leader>. coc#refresh()
+
 " Make <CR> auto-select the first completion item and notify coc.nvim to
 " format on enter, <cr> could be remapped by other vim plugin
 inoremap <silent><expr> <cr> pumvisible() ? coc#_select_confirm()