Support non-word values for cyclic pattern

[xigoi]

It would be nice to be able to do something like this:

patterns[{ "&&", "||" }] = { priority = 10 }
patterns[{ "<", ">" }] = { priority = 10 }

It seems that currently only words (made up of word characters) can be cycled.

[zegervdv]

Currently I'm using matchstrpos() with the \k to match on keyword boundaries.
It seems that && and the likes are in most cases not considered as part of a keyword.
I think if you add & to the iskeyword list, it will probably match, but that will have some unwanted side-effects.

So, I need to figure out how to combine both usecases.