function create_column(column_name)
  if column_name == 'recently modified' then
    command.recently_modified()
  elseif string.match(column_name, '%S+ from %S+') then
    local rel, start_id = string.match(column_name, '(%S+) from (%S+)')
    initialize_cache_if_necessary(start_id)
    local column = unroll_column(start_id, rel)
    if column == nil then
      -- something has changed from underneath us
      -- unroll_column printed out an error
      return
    end
    table.insert(Surface, column)
  elseif string.match(column_name, 'neighbors of %S+') then
    local start_id = string.match(column_name, 'neighbors of (%S+)')
    initialize_cache_if_necessary(start_id)
    local column = {name=('neighbors of %s'):format(start_id)}
    table.insert(column, load_pane_from_file(start_id))
    for rel,target in pairs(Cache[start_id].links) do
      table.insert(column, load_pane_from_file(target))
    end
    table.insert(Surface, column)
  elseif file_exists(Directory..column_name) then
    command.open_file(column_name)
  end
end

      return
    end
  end
end
-- commands that create columns also need to be recreatable from a title
function create_column(column_name)
  if column_name == 'recently modified' then
    command.recently_modified()
  elseif string.match(column_name, '%S+ from %S+') then
    local rel, start_id = string.match(column_name, '(%S+) from (%S+)')
    initialize_cache_if_necessary(start_id)
    local column = unroll_column(start_id, rel)
    if column == nil then
      -- something has changed from underneath us
      -- unroll_column printed out an error

    end
    table.insert(Surface, column)
  elseif string.match(column_name, 'neighbors of %S+') then
    local start_id = string.match(column_name, 'neighbors of (%S+)')
    initialize_cache_if_necessary(start_id)
    local column = {name=('neighbors of %s'):format(start_id)}
    table.insert(column, load_pane_from_file(start_id))
    for rel,target in pairs(Cache[start_id].links) do
      table.insert(column, load_pane_from_file(target))

    table.insert(Surface, column)
  elseif file_exists(Directory..column_name) then
    command.open_file(column_name)