Dealing with sf geometry collections

[see24]

Would it be possible to handle sf geometry collections in a way that preserves all the data? Or if not it would be great if there was a warning that data is being lost.

When I tried to convert an sf object with geometry type "GEOMETRYCOLLECTION" that contains points and lines to a SpatVector it appeared to work but the result only contained the lines.

It would be great if vect could detect that it was a "GEOMETRYCOLLECTION" and either produce a warning or maybe iterate over geometry types and then produce a SpatVectorCollection.

library(terra)
library(sf)

geom_col <- c(st_geometrycollection(list(st_point(1:2), st_linestring(matrix(1:6,3)))),
  st_geometrycollection(list(st_multilinestring(list(matrix(11:16,3)))))) %>% 
  # list() %>% 
  st_sfc() %>% 
  st_sf()

plot(geom_col)

# convert to SpatVector
sv_geom_col <- vect(geom_col)

# Point is gone without warning
plot(sv_geom_col)

# SpatVectorCollection would seem like the right class for it but doesn't work with sf
svc(geom_col)

[rhijmans]

Thank you, I now get:

library(terra)
library(sf)
geom_col <- c(st_geometrycollection(list(st_point(1:2), st_linestring(matrix(1:6,3)))),
  st_geometrycollection(list(st_multilinestring(list(matrix(11:16,3)))))) %>% 
  st_sfc() %>% st_sf()

sv_geom_col <- vect(geom_col)
#Warning message:
#[SpatVector from sf] not all geometries were transferred, use svc for a geometry collection
 
s <- svc(geom_col)
s
# class       : SpatVectorCollection 
# length      : 2 
# geometry    : lines (2)
#               points (1)

Attributes are not transferred yet. I could use a more complex example of an sf object that contains a geometrycollection but also simpler features.