R/sgl_geom_utils.R

In rsgl: An Implementation of the 'SGL' Graphics Language

group_aes_expr <- function(group_cols) {
  if (length(group_cols) == 1) {
    return(as.symbol(group_cols))
  }
  comma_sep_cols <- paste(group_cols, collapse = ", ")
  interaction_str <- paste(
    c("interaction(", comma_sep_cols, ")"),
    collapse = ""
  )
  parse(text = interaction_str)[[1]]
}