Week 1

Q1

a) In Scala, why does evaluate by name mean that the expression has to be re-evaluated each time?
b) Why can it not be evaluated once and substituted in each time?
c) What can you do in your code to evaluate it once, such that the performance overhead is the same as call by value?

Q2

You have seen that evaluating a recursive function that never returns will continue forever, not returning a value (similar to a infinite loop). What would be the benefit of a language that disallowed such features? What would be the drawbacks?