Vim中非空白字符的定义是什么？

Question

Launch vim. In the empty buffer, insert two lines where the first line consists of 3 spaces and the second line consists of hello world .

Here is an example file where the spaces are represented with dots.

...
hello world

Now press gg . The cursor moves to the third space of the first line.

Quoting :help gg :

<C-Home>    or                  *gg* *<C-Home>*
gg          Goto line [count], default first line, on the first
            non-blank character |linewise|.  If 'startofline' not
            set, keep the same column.

The documentation says that the cursor should move to the first non-blank character of the first line. I have two questions.

1. Does :help document the definition of a non-blank character? If so, could you please point me to it?
2. Is the behaviour that we observe in the experiment mentioned above consistent with the documentation provided in :help gg ?

Answer 1

I don't think there is a general definition of non-blank in the vim docs, but I also do not believe this is a "side effect" of gg .

Note that gg is consistent here with ^ :

^          To the first non-blank character of the line.           
           |exclusive| motion.

and [:blank:] of vim's pattern matching behavior ( :h blank ) defines blank characters as space and tab:

*[:blank:]*               [:blank:]     space and tab characters

As far as whether or not this is consistent with gg , consider what it says it will do as two steps instead of one:

1. Go to the first line (default since no count was specified) -- it does this.
2. Go to the first non-blank character of said line.

Probably the easiest way to implement 2 as an algorithm is to position the cursor after all the blank characters at the beginning of the line . In your case, they are all blank characters (and it cannot move to the next line), so the cursor is positioned at the end of the line (after all the blank characters).