Assignment 8: Accumulators (due Nov 3)

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1. (3 pts) Write an accumulator-style program length which consumes a list (of any type) and produces a number. The number should be the count of all elements in the list. For example:

   (length (list 4 5)) = 2

   (length (list 'a 3 'b "hi")) = 4

2. (3 pts) Write an accumulator-style program palindrome which consumes a list of symbols and produces a list of symbols. The program creates a palindrome (a sequence of symbols that reads the same forwards as it does backwards) out of the input list. Here are some examples:

   (palindrome empty) = empty

   (palindrome (list 'a)) = (list 'a)

   (palindrome (list 'a 'b)) = (list 'a 'b 'a)

   (palindrome (list 'w 'e 't 's)) = (list 'w 'e 't 's 't 'e 'w)