Export translate_shape_string() (#5270)

* Export `translate_shape_string()`

* Add NEWS bullet

Author: teunbrand

NAMESPACE

@@ -688,6 +688,7 @@ export(theme_test)
 export(theme_update)
 export(theme_void)
 export(transform_position)
+export(translate_shape_string)
 export(unit)
 export(update_geom_defaults)
 export(update_labels)

NEWS.md

@@ -1,5 +1,9 @@
 # ggplot2 (development version)
 
+* The `translate_shape_string()` internal function is now exported for use in
+  extensions of point layers (@teunbrand, #5191).
+* Fixed bug in `coord_sf()` where graticule lines didn't obey 
+  `panel.grid.major`'s linewidth setting (@teunbrand, #5179)
 * Fixed bug in `annotation_logticks()` when no suitable tick positions could
   be found (@teunbrand, #5248).
 * To improve `width` calculation in bar plots with empty factor levels, 

R/geom-point.R

@@ -143,6 +143,23 @@ GeomPoint <- ggproto("GeomPoint", Geom,
   draw_key = draw_key_point
 )
 
+#' Translating shape strings
+#'
+#' `translate_shape_string()` is a helper function for translating point shapes
+#' given as a character vector into integers that are interpreted by the
+#' grid system.
+#'
+#' @param shape_string A character vector giving point shapes.
+#'
+#' @return An integer vector with translated shapes.
+#' @export
+#' @keywords internal
+#'
+#' @examples
+#' translate_shape_string(c("circle", "square", "triangle"))
+#'
+#' # Strings with 1 or less characters are interpreted as symbols
+#' translate_shape_string(c("a", "b", "?"))
 translate_shape_string <- function(shape_string) {
   # strings of length 0 or 1 are interpreted as symbols by grid
   if (nchar(shape_string[1]) <= 1) {