fpaste.R

# Using `fread` and `fwrite` to paste together columns like `do.call(paste, ...)`
fpaste <- function(dt, sep = ",") {
  x <- tempfile()
  if (sep == "") {
    data.table(V1 = do.call(stringi::stri_join, c(dt, sep = "")))
  } else {
    fwrite(dt, file = x, sep = sep, col.names = FALSE)
    fread(x, sep = "\n", header = FALSE)
  }
}