R/quoted_printable.R

In jimhester/gmailr: Access the 'Gmail' 'RESTful' API

#' Encode text using quoted printable
#'
#' Does no do any line wrapping of the output to 76 characters
#' Implementation derived from the perl MIME::QuotedPrint
#' @param data data to encode
#' @references <http://search.cpan.org/~gaas/MIME-Base64-3.14/QuotedPrint.pm>
#' @export
quoted_printable_encode <- function(data) {
  # All printable ASCII characters (decimal values between 33 and 126) may be represented by themselves, except "=" (decimal 61).
  res <- substitute_regex(data,
    "([^ \t\n!\"#$%&'()*+,\\-./0123456789:;<>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz\\{|\\}~])",
    function(x) sprintf("=%02X", ord(x)),
    perl = TRUE
  )
  res <- substitute_regex(res,
    "([ \t]+)(?=\n|$)",
    function(x) paste0(sprintf("=%02X", ord(x)), collapse = ""),
    perl = TRUE
  )
  res
}