extend metadata from attributes

[dusadrian]

There is useful metadata stored in the attributes of a variable, and it would be nice to have that saved in the database along with the other metadata. Specifically, I am thinking of objects of class "haven_labelled" from package haven (also using a tibble), which have additional information about values to be considered missing:

library(haven)
library(tibble)
test <- tibble(X = labelled_spss(c(1:5, 99), c(Missing = 99)))

test
# # A tibble: 6 x 1
#              X
#      <dbl+lbl>
# 1  1          
# 2  2          
# 3  3          
# 4  4          
# 5  5          
# 6 99 [Missing]

attributes(test$X)
# $labels
# Missing 
#      99 
# 
# $class
# [1] "haven_labelled_spss" "haven_labelled"