R-package text encoding - special characters encoded incorrectly - r

Question

I've got an R-function along these lines:
swedish.weekday <- function(date = Sys.Date()) {
require(lubridate)
c("Sön", "Mån", "Tis", "Ons", "Tor", "Fre", "Lör")[wday(date)]
}
This returns the three letter equivalent of Sun, Mon, Tue etc.
Works absolutely fine until I include this function in a package where during the build the function transforms into:
swedish.weekday <- function(date = Sys.Date()) {
require(lubridate)
c("Sön", "Mån", "Tis", "Ons", "Tor", "Fre", "Lör")[wday(date)]
}
I've tried setting the encoding options in the project settings to either ISO8859-1 or WINDOWS-1252 but neither works. Using 64 bit R 3.1.2 under Windows 7.
Suspect I'd need to change something in the build config but I'm lost as to what - any help/direction much appreciated!

Answer 1

As per the link posted in the comments above I solved the issue by merely using Unicode escapes as such:
day <- c("S\u00F6n", "M\u00E5n", "Tis", "Ons", "Tor", "Fre", "L\u00F6r")[wday(date)]
Edit: While passing these results to an external system (OLAP) I discovered it is also necessary to force the encoding of these results to ISO ("latin-9") to ensure it does not only look correct on the screen but also as far as the system is concerned as such day <- inconv(day, "UTF-8", "latin-9")
For ref...
There is a portable way to have arbitrary text in character strings (only) in your R code, which is to supply them in Unicode as \uxxxx escapes. If there are any characters not in the current encoding the parser will encode the character string as UTF-8 and mark it as such. This applies also to character strings in datasets: they can be prepared using \uxxxx escapes or encoded in UTF-8 in a UTF-8 locale, or even converted to UTF-8 via ‘iconv()’. If you do this, make sure you have ‘R (>= 2.10)’ (or later) in the ‘Depends’ field of the DESCRIPTION file.