Sure - that's not the difficult part, in my book. (I use F#, where there's tuple destructuring syntax, so it's easy.) The hard parts are about making sure you can't reuse the token in the wrong context.

Oooh. Yeah, that makes sense.

I sadly don't know enough F# to even begin to think of something to make the tokens context safe.

For what it's worth, I don't think it's possible in F# (perhaps modulo absurd tricks that will never go into prod code, like type-level naturals).