Q:

Switch back and forth between filetypes in VIM

Similar to how spell checking works. I have a custom syntax I wish to temporary apply to any filetype in the buffer. I figure the best way to do this is just change the filetype. But, I don't know how to get back to previous filetype without being explicit. How can I accomplish this?

A:

You can use :filetype detect to redetect the original filetype.

