Question

Write a procedure, my-filter, which takes a predicate pred and a list s. What does the output of my-filter contain?

a) Elements in random order

b) Elements sorted in ascending order

c) Elements sorted in descending order

d) Elements in the same order as the original list

Answer 1

The procedure 'my-filter' returns a list of elements that satisfy the given predicate, maintaining the order as in the original list.

Step-by-step explanation:

The procedure named my-filter takes a predicate and a list as arguments. The output of this function is a new list that includes all elements from the original list s for which the supplied predicate function (pred) returns true. Importantly, the elements in the output list are in the same order as they appeared in the original list s.

To clarify with an example, assume our predicate function is to find even numbers and our original list is [1, 2, 3, 4, 5]. When we apply my-filter, the result would be [2, 4], which maintains the order of elements as they appeared in the original list.