Default Arguments

Default Arguments

HolyC supports default argument values — a feature that C does not have. You can specify a default for any parameter by writing = value after the type:

I64 Multiply(I64 a, I64 b=2) {
  return a * b;
}

Print("%d\n", Multiply(5));     // 10  (b defaults to 2)
Print("%d\n", Multiply(5, 3));  // 15  (b is 3)

Any Position

Unlike C++, HolyC allows default arguments at any position, not just the end:

I64 Clamp(I64 value, I64 lo=0, I64 hi=100) {
  if (value < lo) return lo;
  if (value > hi) return hi;
  return value;
}

Print("%d\n", Clamp(150));        // 100
Print("%d\n", Clamp(-5));         // 0
Print("%d\n", Clamp(50, 0, 100)); // 50

Practical Use

Default arguments reduce boilerplate for functions that are commonly called with the same values:

U0 PrintHeader(U8 *title, U8 *border="===") {
  Print("%s\n", border);
  Print("%s\n", title);
  Print("%s\n", border);
}

PrintHeader("Welcome");          // uses === borders
PrintHeader("Error", "!!!");     // uses !!! borders

Your Task

Write a function I64 Power(I64 base, I64 exp=2) that raises base to the power exp using a loop.

Call it as Power(4) (should return 16) and Power(2, 8) (should return 256).