R/make_regex.R

In injuryepi/injuryicd10cm: ICD-10-CM Injury Matrix

#' transform the ICD-10-CM codes into an operational regular expression.
#'
#'
#' @param x input variable

#' @return collapse the grouped icd10cm as regular expressions with all the "x" not at the beginning of the icd10cm code replaced by '.' to match any character.
#'
#' @export
#' @importFrom purrr compose
#'
#' @examples
#' library(tidyverse)
#' make_regex(c("X45x2", "Y65xx"))
#'

make_regex <- purrr::compose(
  function(x) paste0("^", x),
  function(x) paste(x, collapse = "|^"),
  function(x) gsub("(?<!^)x", ".", x, ignore.case = T, perl = T)

)