[v3] Implement new Concept Exercise: Character types

Read the linked v3 concept-exercise, rationale, and structure documents first, then inspect existing exercises under languages/clojure/exercises/concept. Create the listed .docs, .meta, source, and test files for the Character types exercise; done means the exercise covers char, string, and regular_expression without representer or analyzer changes.

This issue describes how to implement the Character types concept exercise for the Clojure 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 up on the following documents:

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

Goal

The goal of this exercise is to teach the student how character types are implemented in Clojure. According to the official guide this includes 3 main types: strings, characters and regular expressions.

Things to teach

This exercise aims to teach the student:

• Clojure strings are Java strings - eg. they are immutable
• Contained in double quotes
• Individual characters represented w/ leading backslash \
• Special characters (\newline \spec \tab, etc.)
• Unicode characters (\uNNNN or in octal with \oNNN)
• Literal regex syntax - #"[0-9]+"

Things not to teach

Things outside the scope of this exercise are:

• Advanced regex usage

Concepts

This exercise teaches the following concepts:

• char
• string
• regular_expression

Prerequisites

This is a base-level concept and likewise only assumes general knowledge of English letters.

Resources to refer to

Hints

• Syntax guide

After

• java.util.regex.pattern
• Clojure reference
• Java escape sequences

Representer

This exercise does not require any modifications to the track's representer.

Analyzer

This exercise does not require any special analysis to be added for it.

Implementing

To implement a concept exercise, the following files must be created:

languages
└── clojure
    └── exercises
        └── concept
            └── <SLUG>
                ├── .docs
                |   ├── instructions.md
                |   ├── introduction.md
                |   ├── hints.md
                |   └── after.md (optional)
                ├── .meta
                |   |── design.md
                |   └── Example.clj
                ├── <NAME>.clj
                └── <NAME>_test.clj

Help

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