Tracks on Tracks on Tracks: Incorrect implementation of task 4 passes test for task 4, but fails test for task 6 about clojure

[bobbicodes]

I'm actually in the process of rewriting this exercise because there are several problems with it. It was the first concept exercise anyone made and we didn't know what we were doing yet.

I'm actually confused why it didn't work with pop. In fact, folks use it all the time for that function as it differs from rest only in its handling of the empty list.

The exercise is also out of place, because there's an elegant way to do the composition in the final task (threading macros), but it hasn't been taught yet. Since there's a better exercise for teaching lists (Card Games, I think?), so I think I'm going to port that one, and rework this exercise to teach function composition, which is what task 6 is really asking for.

[tasxatzial]

pop isn't incorrect here. add-language takes an argument of type PersistentList (the initial empty list) and returns a Cons object. pop works by employing a cast of its argument to IPersistentStack but a Cons object isn't a subclass of that interface so it throws an error. In other words pop and cons don't mix.

Changing cons to conj, should fix the error.

[bobbicodes]

Closing this because the exercise was deprecated (see #584). This exercise will confuse students no more :)