R/setSymbol.R

In set6: R6 Mathematical Sets Interface

setSymbol <- function(set, zero = FALSE) {
  if (!inherits(set, "character")) {
    set <- paste0(substitute(set))
  }
  set <- tolower(set)
  zero_str <- ifelse(zero, "0", "")
  if (useUnicode()) {
    return(switch(set,
      naturals = "\u21150",
      posnaturals = "\u2115+",
      integers = "\u2124",
      posintegers = paste0("\u2124", zero_str, "+"),
      negintegers = paste0("\u2124", zero_str, "-"),
      rationals = "\u211A",
      posrationals = paste0("\u211A", zero_str, "+"),
      negrationals = paste0("\u211A", zero_str, "-"),
      reals = "\u211D",
      posreals = paste0("\u211D", zero_str, "+"),
      negreals = paste0("\u211D", zero_str, "-"),
      extendedreals = "\u211D \u222A {-\u221E, +\u221E}",
      complex = "\u2102",
      logicals = "{TRUE, FALSE}",
      universal = "\U1D54D"
    ))
  } else {
    return(switch(set,
      naturals = "N0",
      posnaturals = "N+",
      integers = "Z",
      posintegers = paste0("Z", zero_str, "+"),
      negintegers = paste0("Z", zero_str, "-"),
      rationals = "Q",
      posrationals = paste0("Q", zero_str, "+"),
      negrationals = paste0("Q", zero_str, "-"),
      reals = "R",
      posreals = paste0("R", zero_str, "+"),
      negreals = paste0("R", zero_str, "-"),
      extendedreals = "R U {-Inf, +Inf}",
      complex = "C",
      logicals = "{TRUE, FALSE}",
      universal = "V"
    ))
  }
}