RFC Add is_not_empty methods to vectors (or `is_not_*` generally)

[brson]

We used to have this method but it was removed in favor of !. I still much prefer to write is_not_foo because it reads (and writes) so much better than the prefix bang (no backtracking to figure out what was negated), and checking for non-empty vectors is quite common. Similarly I use is_not_null very frequently.

Is this a pattern we collectively approve of or not?

[thomaslee]

I'm -1 on this because somebody, somewhere, someday will make me sad with double negatives. (In all seriousness :))

[bblum]

I am largely indifferent. Leaning slightly against, because it adds neither expressivity nor convenience (it's even fewer characters for the user to type !is_empty). The Haskell libraries have a zillion convenience functions that are basically minor permutations of each other, but they all help you save characters.

[catamorphism]

Sounds like the response to this RFC was neutral-to-negative. Closing.