Scala coding styles and conventions?

I think Scala goes too far from simplicity, like its syntax. For example Martin Odersky wrote the method in his book :

def calculate(s: String): Int =
  if (cache.contains(s))
    cache(s)
  else {
    val acc = new ChecksumAccumulator
    for (c <- s)
      acc.add(c.toByte)
    val cs = acc.checksum()
    cache += (s -> cs)
    cs
  }

If the methods grows, it becomes very painful to read the code, I can't match curly braces, can't fold the method in IDE. Is there any Scala coding conventions out there? I feel it's too flexible to express a simple method:

def add(b: Byte): Unit = {
  sum += b
}

def add(b: Byte): Unit = sum += b

def add(b: Byte) { sum += b }