R/string.R

In dads2busy/dataplumbr: Helpful Data Plumbing/Engineering Functions

#' Remove non-alphanumeric characters from a string.
#' Optionally remove spaces.
#'
#' @param string A character string.
#' @param keep_spaces Don't remove spaces.
#' @export
#' @examples
#' remove_non_alphanum("222-44-6666")
#' [1] "222446666"
#' char.remove_non_alphanum("Devante Smith-Pelly", keep_spaces = F)
#' [1] "DevanteSmithPelly"
char.remove_non_alphanum <- function(string, keep_spaces = TRUE) {
    if (keep_spaces == TRUE) out <- gsub("[^[:alnum:] ]", "", string)
    if (keep_spaces == FALSE) out <- gsub("[^[:alnum:]]", "", string)
    out
}

#' Convert string to character vector
#'
#' @param string A character string.
#' @param delimeter Optional. Default ",".
#' @export
#' @examples
#' char.string2vector("a,b,c,d")
#' [1] "a" "b" "c" "d"
char.string2vector <- function(string, delimeter=",") {
    unlist(strsplit(string, delimeter))
}

#' Return everything before the first occurence of provided separator.
#'
#' @param string A character string.
#' @param separator Optional. Default ",".
#' @param include_sep_in_output Optional. Include the separator in the output. Default FALSE.
#' @export
#' @examples
#' char.get_before_separator("I am smart enough, good looking enough, and gosh darn it, people like me.")
#' [1] "I am smart enough"
char.get_before_first_separator <-  function(string = "", separator = ",", include_sep_in_output = FALSE) {
    special_chars <- c(".", "?", "#")
    if (separator %in% special_chars) sep <- paste0("\\", separator) else sep <- separator
    out <- trimws(substr(string, 1, regexpr(sep, string)))
    if (include_sep_in_output == FALSE) out <- substr(out, 1, nchar(out) - 1)
    out
}

#' Return everything between first occurence of first separator and first occurence
#' of second separator after the first separator.
#'
#' @param string A character string.
#' @param first_separator Optional. Default ",".
#' @param second_separator Optional. Default ",".
#' @param include_sep_in_output Optional. Include the separators in the output. Default FALSE.
#' @export
#' @examples
#' str <- "I am smart enough, good looking enough, and gosh darn it; people like me."
#' get_between_separators(str)
#' [1] "good looking enough"
#' char.get_between_separators(str, second_separator = ";")
#' [1] "good looking enough, and gosh darn it"
char.get_between_separators <- function(string = "", first_separator = ",", second_separator = ",", include_sep_in_output = FALSE) {
    special_chars <- c(".", "?", "#")
    if (first_separator %in% special_chars) first_sep <- paste0("\\", first_separator) else first_sep <- first_separator
    if (second_separator %in% special_chars) second_sep <- paste0("\\", second_separator) else second_sep <- second_separator
    idx_fst_sep <- regexpr(first_sep, string)
    idx_scd_sep <- regexpr(second_sep, substr(string, idx_fst_sep + 1, nchar(string))) + idx_fst_sep
    out <- trimws(substr(string, idx_fst_sep, idx_scd_sep))
    if (include_sep_in_output == FALSE) out <- substr(out, 2, nchar(out) - 1)
    out
}

#' Return everything between after last occurence of separator and end of the string.
#'
#' @param string A character string.
#' @param separator Default ".".
#' @param include_sep_in_output Optional. Include the separator in the output. Default FALSE.
#' @export
#' @examples
#' str <- "I am smart enough, good looking enough, and gosh darn it; people like me."
#' char.get_after_last_separator(str, separator = ",")
#' [1] " and gosh darn it; people like me."
#' char.get_after_last_separator(str, separator = ",", include_sep_in_output = T)
#' [1] ", and gosh darn it; people like me."
char.get_after_last_separator <- function(string = "a.b?c.net", separator = ".", include_sep_in_output = FALSE) {
    special_chars <- c(".", "?", "#")
    if (separator %in% special_chars) sep <- paste0("\\", separator) else sep <- separator
    re <- paste0(sep, "[^", sep, "]*$")
    idx_lst_sep <- regexpr(re, string)
    out <- trimws(substr(string, idx_lst_sep, nchar(string)))
    if (include_sep_in_output == FALSE) out <- substr(out, 2, nchar(out))
    out
}