In an expression-oriented language such as Algol 68 or Lisp, a while loop (a do loop in Lisp) has a value as an expression. How do you think this value should be determined? (How is it determined in...

In an expression-oriented language such as Algol 68 or Lisp, a while loop (a

do loop in Lisp) has a value as an expression. How do you think this value

should be determined? (How is it determined in Algol 68 and Lisp?) Is

the value a useless artifact of expression orientation, or are there reasonable

programs in which it might actually be used? What do you think should

happen if the condition on the loop is such that the body is never executed?