HMWK4

Due: 12 April 2017, by end of class

1) a) Identify languages which are object-free; have traditional scalars and objects; have only objecrs.

b) Are all sub-classes also sub-types? Why?

c) What language features are lost if space allocation is purely static?

d) fun junk (string x, int y) {.....};
   
   z = junk{y=7; x="fred"};

e) Explain one disadvantage of inheritance.

2) Consider the (pseudo-code) function:   defn fact x =  if x < 2 then 1 else x * fact (x-1);

Show the sequence of stack allocations in the execution of fact(5).

3) Write a ruby function which takes 2 lists (which represent sets) and retun the list representing the union of those two sets.