tests for chapters 8,13
8.1,2 ScalaCheck Prop
14.1 STArray.fill
test for 14.1 STArray.fill
tests for exercise 14.2
tests for exercises 15.1, 15.2
tests for exercises 15.3-4
14.3 STMap
tests for chapter 15
15.12 Process.join
Exercise 2.2
Exercises 2.1, 2.3, 2.4 and 2.5
Exercise 3.2
Exercise 3.3
Exercise 3.4
Exercise 3.5
Exercise 3.6
Exercise 3.9
Exercise 3.10
Exercise 3.11