inoremap <silent><expr> <TAB>
      \ pumvisible() ? coc#_select_confirm() :
      \ coc#expandableOrJumpable() ? "\<C-r>=coc#rpc#request('doKeymap', ['snippets-expand-jump',''])\<CR>" :
      \ <SID>check_back_space() ? "\<TAB>" :
      \ coc#refresh()

function! s:check_back_space() abort
  let col = col('.') - 1
  return !col || getline('.')[col - 1]  =~# '\s'
endfunction

let g:coc_snippet_next = '<tab>'

" <Tab> and <S-Tab> to navigate between choices
inoremap <expr> <Tab> pumvisible() ? "\<C-n>" : "\<Tab>"
inoremap <expr> <S-Tab> pumvisible() ? "\<C-p>" : "\<S-Tab>"

" <cr> to validate selected autocompletion
inoremap <expr> <cr> pumvisible() ? "\<C-y>" : "\<C-g>u\<CR>"

" Use <C-j> for jump to next placeholder, it's default of coc.nvim
let g:coc_snippet_next = '<c-j>'

" Use <C-k> for jump to previous placeholder, it's default of coc.nvim
let g:coc_snippet_prev = '<c-k>'