Convert an object to its abstract array representation (AbstractArray).
Examples
# an R value becomes `RData`: it has no data type of its own yet
to_abstract(1.5)
#> RData(double, ())
to_abstract(1L)
#> RData(integer, ())
to_abstract(TRUE)
#> RData(logical, ())
# an AnvlArray becomes a ConcreteArray
to_abstract(nv_array(1:4))
#> ConcreteArray
#> 1
#> 2
#> 3
#> 4
#> [ CPUi32{4} ]
# use pure = TRUE to strip subclass info
to_abstract(nv_array(1:4), pure = TRUE)
#> AbstractArray(dtype=i32, shape=4)