Explore boolean mental model

[hadley]

E.g. make ! equivalent to !: I suspect people try it and get confused by the error message. It leads to a slightly misleading mental model of how tidyselect works under the hood, but I think the fact that -"x" already works means that we don't need to worry too much.

And make & and | work. We also need to figure out whether to the vectorised or short-circuiting operators are the most intuitive to most people.

[hadley]

Worry: it's easy to say "I want columns x and y", but that's actually select(df, x | y)

[lionel-]

Maybe these operators shouldn't work with bare symbols?

Other cases should be fine, e.g. is.numeric | is.factor, or starts_with("foo") & ends_with("bar").

[hadley]

Yeah, that makes sense - all of the other options are more obviously predicate functions.