nest to reverse unnest's name_sep

[dah33]

unnest includes name_sep which forms the names of the new columns by pasting together the outer column name with the inner names, separated by names_sep.

It would be great if nest had a feature to reverse this action: to remove the outer column name and the separator.

https://tidyr.tidyverse.org/reference/nest.html

[hadley]

library(tidyr)

df <- iris %>% 
  as_tibble() %>% 
  nest(Sepal = starts_with("Sepal"), Petal = starts_with("Petal"))

names(df$Sepal[[1]])
#> [1] "Sepal.Length" "Sepal.Width"

^{Created on 2019-11-24 by the reprex package (v0.3.0)}

Same idea as #795, but for nest() rather than pack()