R -- transform tab delimited string to long format

Question

How to you reshape a string delimited by a tab or space into a long format? The string (called label here) can be of different lengths.

I have this

    var       label
1  work     100 101
2 sleep 500 409 200

and I want this

    var code
1  work  100
2  work  101
3 sleep  500
4 sleep  409
5 sleep  200


# data 
df = data.frame(var = c("work", 'sleep'), label = c('100 101', '500 409 200'))

Answer 1

library(tidyr)
df %>% 
    separate_rows(label)
# A tibble: 5 x 2
  var   label
  <chr> <chr>
1 work  100  
2 work  101  
3 sleep 500  
4 sleep 409  
5 sleep 200