Return only coordinates for points in `sfc_to_df()`?

[kadyb]

I wonder if it would be resonable to only return X and Y coordinates for points when converting geometry to data frame like sf::st_coordinates() does?

library("sf")
library("sfheaders")

n = 100000
df = data.frame(x = rnorm(n), y = rnorm(n))
pts = st_as_sfc(st_as_sf(df, coords = c("x", "y")))

x = sf::st_coordinates(pts)
str(x)
#> num [1:100000, 1:2] -0.4177 -0.0679 0.6598 0.756 0.1694 ...
#> - attr(*, "dimnames")=List of 2
#>  ..$ : NULL
#>  ..$ : chr [1:2] "X" "Y"
format(object.size(x), units = "auto")
#> [1] "1.5 Mb"

y = sfheaders::sfc_to_df(pts)
str(y)
#> 'data.frame':	100000 obs. of  4 variables:
#>  $ sfg_id  : int  1 2 3 4 5 6 7 8 9 10 ...
#>  $ point_id: int  1 2 3 4 5 6 7 8 9 10 ...
#>  $ x       : num  -0.4177 -0.0679 0.6598 0.756 0.1694 ...
#>  $ y       : num  -0.71246 -0.00779 -2.32569 -0.14325 2.83237 ...
format(object.size(y), units = "auto")
#> [1] "2.3 Mb"

t = bench::mark(
  check = FALSE,
  sf = st_coordinates(pts),
  sfheaders = sfc_to_df(pts),
)
t[, 1:5]
#>   expression      min   median `itr/sec` mem_alloc
#> 1 sf           1.72ms   1.78ms     532.     3.05MB
#> 2 sfheaders   28.15ms  29.07ms      34.1     4.2MB