function pack16 input var result new Uint8Array input length for var i

function pack16(input) {
    var result = new Uint8Array(input.length * 2)

    for(var i = 0; i < input.length; i++) {
        result[i * 2 + 0] = (input[i] >> 8) & 0xFF
        result[i * 2 + 1] = (input[i]) & 0xFF
    }

    return result
}

function lzw_encode(data) {
  var dict = {}
  for(var i = 0; i<256; ++i) {
      dict[[i]] = [i];
  }
  var out = new Uint16Array(data.length)
  var outIndex = 0
  var currChar
  var phrase = [ data[0] ]
  var code = 256;

  for (var i=1; i<data.length; i++) {
    currChar = [data[i]];

    if (dict.hasOwnProperty(phrase.concat(currChar))) {
      phrase = phrase.concat(currChar)
    } else {
      var newData = phrase.length > 1 ? [dict[phrase]] : phrase

      for(var index = 0; index < newData.length; ++index) {
          out[outIndex] = newData[index]
          outIndex += 1
      }

      if (code < 65535) {
          var key = phrase.concat(currChar)
          dict[key] = code
          code = code + 1
      }

      phrase = currChar
    }
  }

  var newData = phrase.length > 1 ? [dict[phrase]] : phrase

  for(var index = 0; index < newData.length; ++index) {
    out[outIndex] = newData[index]
    outIndex += 1
  }

    console.log('compressed size: ', outIndex, ', dict size:', code, Object.keys(dict).length)
  return out.subarray(0, outIndex )

}