getbufferllist

function! SortByCurrent(b1, b2)
  return a:b1['current'] == a:b2['current'] ? 0 : a:b1['current'] < a:b2['current'] ? 1 : -1
endfunction
function! SortByAlternate(b1, b2)
  return a:b1['alternate'] == a:b2['alternate'] ? 0 : a:b1['alternate'] < a:b2['alternate'] ? 1 : -1
endfunction
function! GetBufferList()
  redir =>bufliststr
  silent! ls
  redir END
  let bufferlist = map(map(split(bufliststr, '\n'), 'split(v:val, "\\s\\+")'),
        \ '{"number": v:val[0], "line": v:val[4], "name": v:val[2], "current": v:val[1] =~ "%", "alternate": v:val[1] =~ "#", "hidden": v:val[1] =~ "h"}')
  let current = sort(copy(bufferlist), 'SortByCurrent')[0]['number']
  let alternate = sort(copy(bufferlist), 'SortByAlternate')[0]['number']
  return {'list': bufferlist, 'current': current, 'alternate': alternate}
endfunction

echo GetBufferList()