static S ctxGetVar(S name) {
  S value = ctxContext().vars.get(name);
  if (value == null)
    value = ctxContext().globals.get(name);
  if (value == null && name.startsWith("MATCH") && isInteger(name.substring(5)))
    value = get(ctxContext().matches, parseInt(name.substring(5))-1);
  print("ctxGetVar " + name + " = " + sfu(value));
  ret value;
}