code: function(T, C, n, k) {
          var i;
          for (i = 0; i < k; i++) { C[i] = 0; }
          for (i = 0; i < n; i++) { C[T[i]]++; }
      }
docs: we're dispensing with the "arbitrary alphabet" stuff of the source and just using Uint8Arrays. Find the start or end of each bucket.