is it better for $select method with integer index to abort or return the columns? #990

polars::pl$DataFrame(mtcars)$select(1:2)
#> shape: (2, 1)
#> ┌─────┐
#> │     │
#> │ --- │
#> │ i32 │
#> ╞═════╡
#> │ 1   │
#> │ 2   │
#> └─────┘
data.table::as.data.table(mtcars)[, 1:2]
#>       mpg   cyl
#>     <num> <num>
#>  1:  21.0     6
#>  2:  21.0     6
#>  3:  22.8     4
#>  4:  21.4     6
#>  5:  18.7     8
#>  6:  18.1     6
#>  7:  14.3     8
#>  8:  24.4     4
#>  9:  22.8     4
#> 10:  19.2     6
#> 11:  17.8     6
#> 12:  16.4     8
#> 13:  17.3     8
#> 14:  15.2     8
#> 15:  10.4     8
#> 16:  10.4     8
#> 17:  14.7     8
#> 18:  32.4     4
#> 19:  30.4     4
#> 20:  33.9     4
#> 21:  21.5     4
#> 22:  15.5     8
#> 23:  15.2     8
#> 24:  13.3     8
#> 25:  19.2     8
#> 26:  27.3     4
#> 27:  26.0     4
#> 28:  30.4     4
#> 29:  15.8     8
#> 30:  19.7     6
#> 31:  15.0     8
#> 32:  21.4     4
#>       mpg   cyl
dplyr::select(mtcars, 1:2)
#>                      mpg cyl
#> Mazda RX4           21.0   6
#> Mazda RX4 Wag       21.0   6
#> Datsun 710          22.8   4
#> Hornet 4 Drive      21.4   6
#> Hornet Sportabout   18.7   8
#> Valiant             18.1   6
#> Duster 360          14.3   8
#> Merc 240D           24.4   4
#> Merc 230            22.8   4
#> Merc 280            19.2   6
#> Merc 280C           17.8   6
#> Merc 450SE          16.4   8
#> Merc 450SL          17.3   8
#> Merc 450SLC         15.2   8
#> Cadillac Fleetwood  10.4   8
#> Lincoln Continental 10.4   8
#> Chrysler Imperial   14.7   8
#> Fiat 128            32.4   4
#> Honda Civic         30.4   4
#> Toyota Corolla      33.9   4
#> Toyota Corona       21.5   4
#> Dodge Challenger    15.5   8
#> AMC Javelin         15.2   8
#> Camaro Z28          13.3   8
#> Pontiac Firebird    19.2   8
#> Fiat X1-9           27.3   4
#> Porsche 914-2       26.0   4
#> Lotus Europa        30.4   4
#> Ford Pantera L      15.8   8
#> Ferrari Dino        19.7   6
#> Maserati Bora       15.0   8
#> Volvo 142E          21.4   4