ig_to_igr               Convert Irish Grid coordinates to Irish grid
                        references
igr_is_valid            Check if Irish grid references are valid
igr_to_ig               Convert Irish grid references to Irish Grid
                        coordinates
st_igr_as_sf            Convert a data frame containing Irish grid
                        references into an sf object
st_irishgridrefs        Generate Irish grid references from an sf
                        object
