[Sept Sprint] New exercise teaching pointers

[ErikSchierboom]

This is part of our September Spring to get the Go Track in shape. Please read the Overview issue for more details. This exercise is unclaimed. To claim it, please comment below.

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Before building this exercise (or exercises), please read up on the documentation.

We need an exercise for the pointers and nil concepts. These concepts go well together so it makes sense to teach them in the same exercise.

The exercise should teach:

• What pointers are
• Pointer types for primitives
• Which types are already pointers
• Explain that go has no pointer arithmetic
• Referencing and dereferencing syntax
• nil as zero value for the pointer
• pitfalls when working with pointers (always check whether they are nil before dereferencing)

Keep in mind that the concept of pointers might be hard for people coming from languages that don't have explicit pointer types.

[junedev]

We have noticed in the exercise teaching zero-values that it might not make sense to create a separate concept for nil (at least for the current version of this). If you work on this you can also just include the info in the pointers concept instead and have this exercise just teach pointers.

[ErikSchierboom]

have this exercise just teach pointers.

Sounds like that might be better actually, seeing how people often struggle with pointers.

[andrerfcsantos]

Just to be clear, this actually requires the implementation of a concept + exercise, right?

If so, what would be the requirements for the concept?

[junedev]

Yes, exactly. The introduction file of the exercise should cover the list that you find in the issue description. Then you can use that same content as introduction file of the concept. You can also copy the content into about.md of the concept and then think about whether you would like to add more detailed content/examples there etc. Also if some item on the issue description list is not needed in the exercise and not needed to understand the concept in general, then it should be moved to that about.md file of the concept.

Besides introduction and about there is not much needed for a concept, you can find the general documentation on Concepts here https://exercism.org/docs/building/tracks/concepts.

TLDR If you focus on the exercise and its introduction, you have all the minimal things you need for the concept as well.

[ErikSchierboom]

@andrerfcsantos I'm in the process of adding a new exercise, so you can check my PR to give you an idea of what it looks like: #1680 Note that it's perfectly fine to create the exercise in a series of smaller, incremental PRs if you'd like that.

[andrerfcsantos]

@ErikSchierboom @junedev Thanks for the pointers (no pun intended!). But I think I was not clear enough in my previous message, sorry for that. What I meant by "requirements" is what concepts should come before this one, i.e what should we assume the student knows before getting to this concept. This would be relevant to know which examples of pointers we can include.

[junedev]

@andrerfcsantos 🙈 Sorry, totally misunderstood the question.

You can and should put "structs", "maps" and "slices" as prerequisites for this exercise so that you can talk about things like a slice already being a pointer etc. Also the student already knows about the primitive types of course. The student will learn about methods and pointer receivers AFTER this exercise so you should not go into that. If there are other concepts you feel you need as prerequisite and are unsure about, just leave me another comment.

[andrerfcsantos]

Since no one seems to be claiming this one and we are near Oct 1, I'll work on this one.

[ErikSchierboom]

@andrerfcsantos Let me know if there is anything I can do to help.