Comma separated list in Haskell. Uses an Oxford comma as God intended.

gistfile1.txt

    oxfordian []      = ""
    oxfordian [x]     = x
    oxfordian [x,y]   = x ++ " and " ++ y
    oxfordian [x,y,z] = x ++ ", " ++ y ++ ", and " ++ z
    oxfordian (x:xs)  = x ++ ", " ++ oxfordian xs