I intend to use this to optionally share the search buffer between different Vim instances. I'll have a file on the filesystem that contains the content. So it means I need to set the search register with the contents of a file.
I'm hoping there's a clean Vimscript way to do this. It's ok if it uses python or any other language integration too.
I think this is how to edit the register:
let @/ = [whatever]