1as_unknown_rows <- function(x) { 2 x <- as_tbl(x) 3 class(x) <- c("unknown_rows", "tbl") 4 x 5} 6 7local_unknown_rows <- function(frame = caller_env()) { 8 local_methods( 9 .frame = frame, 10 as.data.frame.unknown_rows = function(x, ...) { 11 class(x) <- "data.frame" 12 x 13 }, 14 dim.unknown_rows = function(x) { 15 c(NA_integer_, length(x)) 16 }, 17 head.unknown_rows = function(x, n) { 18 class(x) <- "data.frame" 19 head(x, n) 20 } 21 ) 22} 23