Place cursor on opening brace, press "=%", why does the closing brace get indented (in addition to desired indentation of lines between the braces)?

Question

I am following along in the book Vi IMproved by Steve Oualline.

In Chapter 7, "Commands for Programmers", there is a discussion about indentation and the = command.

Here is what I wrote in my file

{
if True
return 1;
statement;
statement;
}

Then, as instructed by the book, I positioned my cursor on the first "{" and pressed "=%". The result was

{
        if True
        return 1;
        statement;
        statement;
        }

The book shows only the content within the braces being indented.

Why is the closing brace being indented?

Answer 1

The automatic indentation of the file generated by the = command (e.g. =% or =G) depend on your file type and your file type implementation.

I can reproduce your problem when the filetype of the text (:set filetype?).

You have the odd behavior because the code block are not grouped with curly braces ({ }) in Python.

If you select a file type that is curly base compatible you will not have that effect.

:set filetype=c