autoindent是vim中smartindent的子集？

:help autoindent : copy indent from current line when starting a new line (typing
in Insert mode or when using the “o” or “O” command). …

:help smartindent : Do smart autoindenting when starting a new line. Works for C-like
programs,but can also be used for other languages. …

normally ‘autoindent’ should also be on when using ‘smartindent’.
An indent is automatically inserted:

• After a line ending in ‘{‘.
• After a line starting with a keyword from ‘cinwords’.

• Before a line starting with ‘}’ (only with the “O” command).

  When typing ‘}’ as the first character in a new line,that line is
  given the same indent as the matching ‘{‘. …

smartindent在开始新行时也可以从当前行处理缩进。这意味着autoindent功能是smartindent功能的子集，如果smartindent打开，则不需要autoindent，对吗？为什么要打开autoindent？

smartindent是一个古老的剧本，当它被写成时，是一个“聪明”的补充自动缩进。从那时起，大多数语言都有特定的缩进功能，或者使用具有特定选项的cindent。

一般来说，smartindent不应该被使用。

以下行通常足以处理缩进：

set autoindent
filetype plugin indent on

autoindent并不是绝对必要的，但在使用明文时很有用。