Playing around with bytes and bits - based on a couple of forum threads on the Sept 2013 "Functional Programming Principles in Scala" MOOC on Coursera (progfun).

bitsAndBytes.scala

val bytes = List[Byte](0, 1, -1, 127, -128) 
  
def toBits(b: Byte) = 0 to 7 map (b >> _ & 1)

val bits = bytes flatMap toBits
                                // Note: least-significant bit on the left!
                                // List(0, 0, 0, 0, 0, 0, 0, 0, 
                                //      1, 0, 0, 0, 0, 0, 0, 0, 
                                //      1, 1, 1, 1, 1, 1, 1, 1, 
                                //      1, 1, 1, 1, 1, 1, 1, 0,
                                //      0, 0, 0, 0, 0, 0, 0, 1

def bits2Byte(bs: Seq[Bit]): Int = bs.zipWithIndex.foldLeft(0) { case (acc, (b, i)) => acc | b << i }.toByte

def packBits(bs: Seq[Bit]) = bs.grouped(8).map(bits2Byte)

packBits(bits).toList           
                                // List(0, 1, -1, 127, -128)