Please use Scala without using return

2. Problem

Enhance isPal by making a function isPal2 that ignores case, punctuation, and white space:

isPal2("A man, a plan, a canal, Panama!") => true

Hint: filter out undesirable characters, change everything to lowercase, then use the function defined in #1.

3. Problem

Write a random word generator:

val a1 = mkWord() => a1 : String = ltiki val a2 = mkWord() => a2 : String = iceqy val a3 = mkWord() => a3 : String = dcjjq val a4 = mkWord(20) => a4 : String = rlazfucnscevefzaaviv