unimplemented type error in 'EncodeElement' when column contains list

[artmg]

Many thanks for developing and maintaining this handy package. Your readme shows how to use in on data.frames comprising vector columns, but unfortunately my data processing is returning a data.frame that includes columns based on lists. When I try to copy such a dataframe to the clipboard it fails with unimplemented type 'list' in 'EncodeElement'

### show environment and package versions
rstudioapi::versionInfo()$version
Sys.getenv("R_PLATFORM")
version$version.string

[1] ‘2024.12.0.467’
[1] "aarch64-apple-darwin23.6.0"
[1] "R version 4.4.2 (2024-10-31)"

> packageVersion("clipr")
[1] ‘0.8.0’

Here is a reprex of my issue:

# try as list columns
list_table <- structure(list(
  date = list("05/01/2025", "12/01/2025", "19/01/2025", "26/01/2025", "02/02/2025"), 
    date_text = list("Sun 5", "Sun 12", "Sun 19", "Sun 26", "Sun 2"), 
    occasion = list("Intro", "Topic A", "Topic B", "Topic C", "Summary"), 
  colour = list("White", "White", "Greeen", "Greeen", "White")), 
  row.names = 1:5, class = "data.frame")
clipr::write_clip(list_table)

This throws the error: Error in (function (x, file = "", append = FALSE, quote = TRUE, sep = " ", : unimplemented type 'list' in 'EncodeElement'

I have to use the workaround:

# convert the list columns into vectors
fixed_tab <- as.data.frame(lapply(list_table, function(col) {
  if (is.list(col)) unlist(col) else col
}))
clipr::write_clip(fixed_tab)

and now because all my lists have been converted to vectors, the data is copied to the clipboard as expected.

This behaviour was not previously documented – could a workaround, fix or option perhaps be accommodated by a future version of your package? Note that unlisting a column could have unexpected impacts with certain structures of data, but one would hope that a data.frame (intended for pasting as a table) actually contains reasonably rectangular data.