add label_lut()

R/label-lut.R

@@ -0,0 +1,22 @@
+
+label_lut <- function(lut = character(), nomatch = NULL) {
+
+  if (!is.character(lut)) {
+    cli::cli_abort("The {.arg lut} argument must be a character vector.")
+  }
+  if (!is_named2(lut)) {
+    cli::cli_abort("The {.arg lut} argument must have names.")
+  }
+  names <- names(lut)
+  values <- unname(lut)
+
+  force(nomatch)
+
+  function(x) {
+    i <- match(x, names, nomatch = NA_integer_)
+    out <- values[i]
+    missing <- is.na(i)
+    out[missing] <- if (is.null(nomatch)) x[missing] else nomatch
+    out
+  }
+}