Problem Statement

Define a function/method/subroutine which sorts a sequence ("table") of sequences ("rows") of strings ("cells"), by one of the strings. Besides the input to be sorted, it shall have the following optional parameters: This task should be considered to include both positional and named optional parameters, as well as overloading on argument count as in Java or selector name as in Smalltalk, or, in the extreme, using different function names. Provide these variations of sorting in whatever way is most natural to your language. If the language supports both methods naturally, you are encouraged to describe both. Do not implement a sorting algorithm; this task is about the interface. If you can't use a built-in sort routine, just omit the implementation (with a comment). See also:

Let's start with the solution:

sort(v, ordering=0, column=0, reverse=0)

/*
GP;install("test_func", "vDG", "test", "path/to/test.gp.so");
*/
void
test_func(GEN x) {
  if (x == NULL)
    pari_printf("Argument omitted.\n");
  else
    pari_printf("Argument was: %Ps\n", x);
}