#=
cons(a, b) constructs a pair, and car(pair) and cdr(pair) returns the first and last element of that pair. For example, car(cons(3, 4)) returns 3, and cdr(cons(3, 4)) returns 4.

Given this implementation of cons:

def cons(a, b):
    def pair(f):
        return f(a, b)
    return pair

Implement car and cdr.
=#

function cons(a,b)
    function pair(f)
        return f(a,b)
    end
    return pair
end

function car(pair)
    return getfield(pair, 1)
end

function cdr(pair)
    return getfield(pair,2)
end
