import "libc.hff";

union Val {
   u u32,
   f f32,
}


enum Color : i16 {
   Red, Green, Blue
}

defmacro each(i, x, arr, &body) [
   for let i = 0z; i < arr.#len; ++i {
      let x = arr[i];
      body
   }
]

static xs *void = {};

fn isort(xs *int, n usize) void {
   fn icmp(lhs *const void, rhs *const void, _ *void) int {
      let lhs = *as(*int)lhs,
          rhs = *as(*int)rhs;
      return lhs - rhs;
   }
   qsort(xs, n, 4, &icmp);

   fn foo() void {}
   let x= &foo;
   x();
}

struct List;
struct List {
   next *List,
   val int,
   
   fn ok(l List) void;

   fn length(l *List) usize {
      let n = 0z;
      ok(*l);
      for ; l; l = l.next { ++n; }
      return n;
   }

   fn ok(l List) void {}
}

struct Vec2f;
struct Vec2f {
   x f32,
   y f32,

   fn mag(v Vec2f) f32 {
      extern fn sqrtf(_ f32) f32;
      return sqrtf((v.x * v.x) + (v.y * v.y));
   }
   fn zero(v *Vec2f) void {
      v.x = 0;
      v.y = 0;
   }
}

fn spanz(cstr *const u8) [#]const u8 {
   extern fn strlen(s *const u8) usize;
   return cstr[0 :: strlen(cstr)];
}

defmacro transmute(Type, x) [
   (do
      union T { from typeof(x), to Type };
      (T{x}).to;
   )
]

enum union Number {
   none,
   int i64,
   flo f32,
}

defmacro match(ty, x, &body) [
   (do
      let $res ty = {};
      #'match do {
         defmacro yield(X) [ $res = (X); break #'match ]
         switch (x) body
      } while #f;
      $res;
   )
]

extern fn main (argc int, argv **u8) int {

   let colors [3]Color = { :Red, :Green, :Blue } ;
   let x = Vec2f { .y: 1, .x: 2.4 };
   let p *const Vec2f = &x;
   printf("v = { %g, %g }\n", x.x, p.y);
   printf("mag = %g\n", x->mag());
   Vec2f:zero(&x);
   printf("mag = %g\n", (&x)->mag());

   let x = Number:none;
   let x = Number:int{};

   printf("match: %d\n", match(int, x) {
      case none;  yield(42);
      case int i; yield(i - 7);
      case flo f; yield(f * 0.5f);
   });


   let is []int = { [4] = 1, 2, [1 - 1] = 3 };
   isort(is, is.#len);
   each(i, x, is) {
      printf("%d\n", x);
   }
   let slice [#]int = is[3::5];

   static test *const u8 = "hi";

   printf("sl %d\n", slice[0]);
   slice = slice[1::4];
   printf("sl %d\n", slice[0]);
   slice.#len;
   printf("%c\n", "ABCD"[1::][1::2][1]);

   let const v Vec2f = {};
   // v->zero();
   // v.x += 1;

   printf("sizeof(is) = %zu\n", sizeof(is));
   printf("sizeof *void = %zu\n", sizeof *void);
   printf("alignof f64= %zu\n", alignof f64);
   printf("1.2 -> %#.8x\n", transmute(u32, 1.2f));

   switch is.#len {
   case 0, 1;
      is.#len < 2;
   case 3;
      3;
   case else;
      "idk";
   }
   
   switch colors[0] {
   case :Red;
   }


   return 0;
}