As you probably know, there is ability to enter some specific characters in vim using digraphs (In input mode Ctrl+K Rg produces ® for example).
Is there a way, to define hotkey, to enter the mode which allows me to input multiple digraphs? For example, to write "sayonara" instead of "Ctrl+K sa Ctrl+K yo Ctrl+K na Ctrl+K ra" to get "さよなら".
Not that I know. However you can imagine this:
exec 'normal! i' . substitute('sayonara', '\(..\)', nr2char(11) . '\1', 'g')
nr2char(11) is a CTRL-K character.
If you want a mapping for that (for example in visual mode hit F1 over the selection to transform it; use this on one-line characterwise selection only):
xnoremap <f1> d:exec 'normal! a' . substitute(@", '\(..\)', nr2char(11) . '\1', 'g')<ENTER>
There might be more proper ways to do that (without erasing the contents of the default register) but I will be too lazy for today. I suspect some Stackers might want to post another answer with cleaner code, they'll get my upvote.