Use setfiletype in ftdetect to avoid loading twice.

[averms]

This is the "correct" way of doing it and is what the official vim runtime files do

[wsdjeg]

but it is same as au BufRead,BufNewFile *.rkt,*.rktl set filetype=racket becasuse in this automd there is only one line vim script.

[averms]

but it is same as au BufRead,BufNewFile .rkt,.rktl set filetype=racket becasuse in this automd there
is only one line vim script.

If, in the future, the official vim distribution adds racket to filetype.vim then our ftdetect will
source the racket stuff twice which slows down loading and could break things. You are right that this doesn't help now, but it might help in the future (plus there is no cost). The rust.vim maintainers had to deal with this.

[wsdjeg]

no，because this are two different autocmd.

[wlangstroth]

Thanks!

[jubnzv]

Strange, but this commit breaks filetype detection in clean neovim (v 0.4.0) setup.
Should I also add this autocommand in my neovim configuration?

[averms]

Strange, but this commit breaks filetype detection in clean neovim (v 0.4.0) setup.

Oh fuck you're right I'm really dumb. We do need to override vim's official files in this case because they set *.rkt as scheme.

@wlangstroth can you revert?
Maybe we should add a comment that says why we are using the filetype= way of doing it.