Have st_write() return obj invisibly?

[mpjashby]

It may be useful to have st_write() return the value of the first argument obj invisibly, so that it can be used within magrittr pipelines and be consistent with, for example, the readr::write_*() family. This would allow code such as:

some_sf_data %>%
  st_write("sf_data.gpkg") %>%
  rmapshaper::ms_simplify(keep = 0.1) %>% 
  st_write("sf_data_simplified.gpkg") %>%
  dplyr::glimpse()

Other use cases would include needing to export the same data in multiple formats, or exporting spatial data, removing the geometry column with st_set_geometry(NULL) and then saving the remaining non-spatial data.

[edzer]

Is there some other tidyverse function that writes, and does this too?

[mpjashby]

Sorry, I meant to say readr::write_*() rather than readr::read_delim() and have corrected it now above.

Several other Tidyverse functions do this, including the haven::write_*() family and (in a slightly different context) dbplyr::copy_to().

The Tidyverse style guide (section 3.3) says:

If your function is called primarily for its side-effects (like printing, plotting, or saving to disk), it should return the first argument invisibly. This makes it possible to use the function as part of a pipe.

A similar point is made in The tidy tools manifesto. Apologies for not linking to these other resources when I opened the issue!

[edzer]

Good idea - thanks!