import "all.hff";

extern fn malloc(n usize) *void;
struct Vec<T> {
   dat *T,
   len uint,
   cap uint,

   fn push(vec *Vec, x T) void {
      if vec.len >= vec.cap {
         vec.cap = (vec.len + 1) > 8 ? (vec.len + 1) * 2 : 8;
         if vec.dat == #null {
            vec.dat = malloc(vec.cap * sizeof T);
            assert(vec.dat != #null, "malloc");
         } else {
            vec.dat = realloc(vec.dat, vec.cap * sizeof T);
            assert(vec.dat != #null, "realloc");
         }
      }
      vec.dat[vec.len++] = x;
   }

   fn clear(vec *Vec) void {
      free(vec.dat);
      vec.len = 0;
      vec.cap = 0; 
   }

   fn compact(vec *Vec) [#]T {
      if vec.dat {
         vec.cap = vec.len;
         vec.dat = realloc(vec.dat, vec.cap * sizeof T);
      }
      return vec.dat[0::vec.len];
   }
}

defmacro vec_each(x, i, v, ...body) [
   {
      let $v = v;
      for let i = 0; i < $v.len; ++i {
         let x = v.dat[i];
         { body }
      }
   }
]