additionalInput := &[SeedSize]byte{ 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, } want := []byte{ 0x6e, 0x6e, 0x47, 0x9d, 0x24, 0xf8, 0x6a, 0x3b, 0x77, 0x87, 0xa8, 0xf8, 0x18, 0x6d, 0x98, 0x5a, 0x53, 0xbe, 0xbe, 0xed, 0xde, 0xab, 0x92, 0x28, 0xf0, 0xf4, 0xac, 0x6e, 0x10,...

    sectionIndexBuffer.writeByte((section and 0x3f80) shr 7)

    // Section index.
    sectionIndexBuffer.writeByte((sectionOffset and 0x3f80) shr 7)
    sectionIndexBuffer.writeByte(sectionOffset and 0x7f)

    // Ranges.
    for (range in sectionMappedRanges) {
      rangesBuffer.writeByte(range.rangeStart)

      when (range) {
        is MappedRange.Constant -> {
          rangesBuffer.writeByte(range.b1)

    // Mixed string
    // "a\u020ac\u00a2b\\u024B62u020acc\u00a2de\u024B62"
    assertWellFormed(
        0x61, 0xc8, 0x8a, 0x63, 0xc2, 0xa2, 0x62, 0x5c, 0x75, 0x30, 0x32, 0x34, 0x42, 0x36, 0x32,
        0x75, 0x30, 0x32, 0x30, 0x61, 0x63, 0x63, 0xc2, 0xa2, 0x64, 0x65, 0xc9, 0x8b, 0x36, 0x32);
    // Not a valid string
    assertNotWellFormed(-1, 0, -1, 0);
  }

 */
@Suppress("NAME_SHADOWING")
object Hpack {
  private const val PREFIX_4_BITS = 0x0f
  private const val PREFIX_5_BITS = 0x1f
  private const val PREFIX_6_BITS = 0x3f
  private const val PREFIX_7_BITS = 0x7f

  private const val SETTINGS_HEADER_TABLE_SIZE = 4_096

  /**
   * The decoder has ultimate control of the maximum size of the dynamic table but we can choose

  val sourceCodePoint1: Int,
  val type: Int,
  val mappedTo: ByteString,
) {
  val section: Int
    get() = sourceCodePoint0 and 0x1fff80

  val rangeStart: Int
    get() = sourceCodePoint0 and 0x7f

  val hasSingleSourceCodePoint: Boolean
    get() = sourceCodePoint0 == sourceCodePoint1

  val spansSections: Boolean
    get() = (sourceCodePoint0 and 0x1fff80) != (sourceCodePoint1 and 0x1fff80)

		if b[0]&0x40 != 0 {
			inv = 0xff
		}

		var x uint64
		for i, c := range b {
			c ^= inv // Inverts c only if inv is 0xff, otherwise does nothing
			if i == 0 {
				c &= 0x7f // Ignore signal bit in first byte
			}
			if (x >> 56) > 0 {
				p.err = ErrHeader // Integer overflow
				return 0
			}
			x = x<<8 | uint64(c)
		}
		if (x >> 63) > 0 {

   * in (by dividing by 4) and out (by multiplying by 4).
   */
  private fun findRangesOffset(
    codePoint: Int,
    position: Int,
    limit: Int,
  ): Int {
    val target = codePoint and 0x7f
    val offset =
      binarySearch(
        position = position,
        limit = limit,
      ) { index ->
        val entryIndex = index * 4
        val b0 = ranges[entryIndex].code

      encodings[0x1c] = encoding // File Separator
      encodings[0x1d] = encoding // Group Separator
      encodings[0x1e] = encoding // Record Separator
      encodings[0x1f] = encoding // Unit Separator
      encodings[0x7f] = encoding // Delete
    }

  fun nonAscii(encoding: Encoding) =
    apply {
      encodings[UNICODE_2] = encoding
      encodings[UNICODE_3] = encoding
      encodings[UNICODE_4] = encoding
    }

   * prefix, or when one array is a prefix of the other, treats the shorter array as the lesser. For
   * example, {@code [] < [0x01] < [0x01, 0x7F] < [0x01, 0x80] < [0x02]}. Values are treated as
   * unsigned.
   *
   * <p>The returned comparator is inconsistent with {@link Object#equals(Object)} (since arrays

// TODO: update when package unicode captures more of the properties.
func isSeparator(r rune) bool {
	// ASCII alphanumerics and underscore are not separators
	if r <= 0x7F {
		switch {
		case '0' <= r && r <= '9':
			return false
		case 'a' <= r && r <= 'z':
			return false
		case 'A' <= r && r <= 'Z':
			return false
		case r == '_':
			return false
		}