R exercise: http://adv-r.had.co.nz/Functions.html Create a list of all the replacement functions found in the base package. Which ones are primitive functions?

gistfile1.r

x <- ls("package:base")
x[substring(x, nchar(x)-1, nchar(x)) == '<-']

# "[[<-"             "[<-"              "@<-"              "<-"               "<<-"              "$<-"              "attr<-"           "attributes<-"     "body<-"           "class<-"          "colnames<-"       "comment<-"        "diag<-"           "dim<-"
# "dimnames<-"       "Encoding<-"       "environment<-"    "formals<-"        "is.na<-"          "length<-"         "levels<-"         "mode<-"           "mostattributes<-" "names<-"          "oldClass<-"       "parent.env<-"     "regmatches<-"     "row.names<-"
# "rownames<-"       "split<-"          "storage.mode<-"   "substr<-"         "substring<-"      "units<-"