Ruby 一行 if return 语句

Question

有没有办法在 Ruby 上缩短这一行？

if (res = bla_permission_invalid).is_a? String then return res end

上

def something # many things that like this
  if (res = bla_permission_invalid).is_a? String then return res end
  # do something else
  return true
end

当 bla_permission_invalid 的内容是这样的时候

def bla_permission_invalid
  return invalid_address_report_func if invalid_address?
  return permission_error_report_func if @user.not_one_of? [ :group1, :group2 ]
  return nil
end

invalid_adress_report_func 和 permission_error_report_func 返回字符串

Answer 1

如果可能的值是String和NilClass，那么代码可以简化为:

def something
  res = bla_permission_invalid()
  return res if res # strings are truthy, so they'll be returned but nil will proceed

  # do something else
  true
end