Wishlist: auto_format modified lines only?

[dnwe]

Is it possible to provide g:clang_format#auto_format but which only reformats the lines that have been modified since the buffer was last saved?

[rhysd]

No, it's not possible.

Each chunk of modified lines requires executeing clang-format to format. It'll be a heavy work for Vim and it takes a lot, I think.
Though there is no feature to format modified lines automatically, I think it is better way to format per each modifying with remembering the line when you enter insert mode and invoking clang-format automatically when you leave insert mode. You can hook these points using InsertEnter and InsertLeave events.

[rhysd]

Hi, I added automatic formatting on InsertLeave as a trial at c83f840.

If g:clang_format#auto_format_on_insert_leave is 1, inserted lines are automatically on leaving insert mode. Please be careful because this feature has some side effects.

• Sometimes auto-formatting moves screen unintentionally.
• Cursor position history is polluted (Issue Cursor position not maintained after undo #8).