CharNumSplit.R

#' Split Vectors in the Form of Numbers+Characters or Characters+Numbers into Respective Parts
#' 
#' A convenience function for the `perl = TRUE` patterns for 
#' `"(?<=[a-zA-Z])(?=[0-9])"` and `"(?<=[0-9])(?=[a-zA-Z])"`. That's it. Really.
#' 
#' @param string The string to be split.
#' @param alphaFirst Logical. Characters first (`TRUE`)? Or numbers (`FALSE`)?
#' @return A `list` with the split values.
#' @author Ananda Mahto
#' @references <http://stackoverflow.com/a/23052016/1270695>
#' @examples
#' 
#' STR1 <- c("ABC123", "BCD234", "CDE345", "DEF456")
#' STR2 <- c("123ABC", "234BCD", "345CDE", "456DEF")
#' 
#' CharNumSplit(STR1, alphaFirst = TRUE)
#' CharNumSplit(STR2, alphaFirst = FALSE)
#' 
#' @export CharNumSplit
CharNumSplit <- function(string, alphaFirst = TRUE) {
  Pattern <- ifelse(isTRUE(alphaFirst), "(?<=[a-zA-Z])(?=[0-9])", "(?<=[0-9])(?=[a-zA-Z])")
  strsplit(string, split = Pattern, perl = T)
}