I am new to ViM customization. I am almost done getting autocompletion to work as I would like. Here is the line of interest:
inoremap <expr> i (pumvisible() ? '' : 'i<C-n>') . '<Down>'
Notice that it captures i and then still types it (and then sends
<C-n>). I would like for this to work like a regular expression. How can I get this to work with any word character? I'd rather not have several copies of this each for a different character.