sclass ByteBuffer implements Iterable<Byte> {

  byte[] data;

  int size;

  *() {}

  *(int size) { if (size != 0) data = new byte[size]; }

  *(Iterable<Byte> l) {

    if (l cast Cl) allocate(l.size());

    addAll(l);

  }

  *(byte[] data) { this.data = data; size = l(data); }

  // TODO *(ByteBuffer buf) { ... }

  void add(int idx, int i) {

    add(0);

    arraycopy(data, idx, data, idx+1, size-(idx+1));

    data[idx] = (byte) i;

  }

  void add(int i) { add((byte) i); }

  void add(byte i) {

    if (size >= lByteArray(data)) {

      allocate(Math.max(1, toInt(Math.min(maximumSafeArraySize(), lByteArray(data)*2L))));

      if (size >= data.length) fail("ByteBuffer too large: " + size);

    }

    data[size++] = i;

  }

  void allocate(int n) {

    data = resizeByteArray(data, max(n, size()));

  }

  void addAll(Iterable<Byte> l) {

    if (l != null) for (byte i : l) add(i);

  }

  byte[] toArray aka toByteArray() {

    ret size == 0 ? null : resizeByteArray(data, size);

  }

  L<Byte> toList() {

    ret byteArrayToList(data, 0, size);

  }

  L<Byte> asVirtualList() {

    ret new RandomAccessAbstractList<Byte> {

      public int size() { ret size; }

      public Byte get(int i) { ret ByteBuffer.this.get(i); }

      public Byte set(int i, Byte val) {

        Byte a = get(i);

        data[i] = val;

        ret a;

      }

    };

  }

  void reset { size = 0; }

  void clear { reset(); }

  int size() { ret size; }

  bool isEmpty() { ret size == 0; }

  byte get(int idx) {

    if (idx >= size) fail("Index out of range: " + idx + "/" + size);

    ret data[idx];

  }

  void set(int idx, byte value) {

    if (idx >= size) fail("Index out of range: " + idx + "/" + size);

    data[idx] = value;

  }

  byte popLast() {

    if (size == 0) fail("empty buffer");

    ret data[--size];

  }

  // unefficient

  byte popFirst() {

    if (size == 0) fail("empty buffer");

    byte b = data[0];

    arraycopy(data, 1, 0, --size);

    ret b;

  }

  byte last() { ret data[size-1]; }

  byte nextToLast() { ret data[size-2]; }

  toString { ret squareBracket(joinWithSpace(toList())); }

  public Iterator<Byte> iterator() {

    ret new ItIt<Byte> {

      int i = 0;

      public bool hasNext() { ret i < size; }

      public Byte next() {

        //if (!hasNext()) fail("Index out of bounds: " + i);

        ret data[i++];

      }

    };

  }

  /*public ByteIterator byteIterator() {

    ret new ByteIterator {

      int i = 0;

      public bool hasNext() { ret i < size; }

      public int next() {

        //if (!hasNext()) fail("Index out of bounds: " + i);

        ret data[i++];

      }

      toString { ret "Iterator@" + i + " over " + ByteBuffer.this; }

    };

  }*/

  void trimToSize {

    data = resizeByteArray(data, size);

  }

  int indexOf(byte b) {

    for i to size:

      if (data[i] == b)

        ret i;

    ret -1;

  }

  byte[] subArray(int start, int end) {

    ret subByteArray(data, start, min(end, size));

  }

}