[v3] Implement new Concept Exercise: initialization

[wneumann]

This issue describes how to implement the initialization concept exercise for the Swift track.

Getting started

Please please please read the docs before starting. Posting PRs without reading these docs will be a lot more frustrating for you during the review cycle, and exhaust Exercism's maintainers' time. So, before diving into the implementation, please read the following documents:

• The features of v3.
• Rationale for v3.
• What are concept exercises and how are they structured?

Please also watch the following video:

• The Anatomy of a Concept Exercise.

Goal

This concept exercise should convey a basic understanding of how to perform initialization of structs, classes, and enumerations in Swift.

Things to teach

• Default property values
• Custom initializers
• Default initializers
• Initialization using a closure or function

Things not to teach

• Failable initializers
• Delegated initializers
• Convenience initializers
• Required initializers

Concepts

• initialization

Prerequisites

• structs-and-classes
• enumerations

Resources to refer to

Hints

• Setting initial values
• Custom initializers
• Default initializers
• Initializing using closures

After

• Setting initial values
• Custom initializers
• Default initializers
• Initializing using closures

Representer

TBD

Analyzer

TBD

Implementing

See the Swift track implementation guide for guidance.

Help

If you have any questions while implementing the exercise, please post the questions as comments in this issue.