Strplit code
John Fox wrote:
Dear Wacek, "Wrong" is a bit strong, I think -- limited to single-pattern characters is more accurate.
nothing is ever wrong if seen from an appropriate perspective. for example, there is nothing wrong in that many core functions in r deparse some, but not all, of the argument expressions, without any obvious pattern -- when you get used to it and learn each single case by heart, it's perfectly correct.
Moreover, it isn't hard to make the function work with multiple-character matches as well:
which you probably should have done before posting the flawed version.
Strsplit <- function(x, split){
if (length(x) > 1) {
return(lapply(x, Strsplit, split)) # vectorization
}
result <- character(0)
if (nchar(x) == 0) return(result)
posn <- regexpr(split, x)
if (posn <= 0) return(x)
c(result, substring(x, 1, posn - 1),
Recall(substring(x, posn + attr(posn, "match.length"),
nchar(x)), split)) # recursion
}
On the other hand, your function is much more efficient.
just one order of magnitude in my tests. might not be completely fool proof, though. vQ