Ensure that recycling uses tidyverse rules

[hadley]

i.e. only recycle vectors of length 1.

Problems include at least:

purrr:::recycle_args(list(1, integer(0)))
#> Error in purrr:::recycle_args(list(1, integer(0))): all(lengths == 1L | lengths == n) is not TRUE
purrr::map2(integer(0), 1:2, list)
#> list()
purrr::pmap(list(integer(0), 1:2), list)
#> list()

^{Created on 2022-08-24 by the reprex package (v2.0.1)}

[hadley]

Make sure to also test that data frames are correctly recycled:

purrr::modify2(data.frame(x = 1), 1:2, ~ .)

[hadley]

And

library(purrr)
x <- list(x = 10, y = 20)
names(imodify(x[1:2], \(x, y) x * 2))
#> [1] "x" "y"
names(imodify(x[1], \(x, y) x * 2))
#> NULL

^{Created on 2022-08-27 by the reprex package (v2.0.1)}