Implement new Concept Exercise: expressions

[ErikSchierboom]

This issue describes how to implement the expressions concept exercise for the F# 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?

Please also watch the following video:

• The Anatomy of a Concept Exercise.

Goal

The goal of this exercise is to teach the student the basics of the Concept of Expressions in F#.

Learning objectives

• Know what expressions are.
• Know how expressions are different from statements.
• Know what pure functions are.
• Know what the unit type is.
• Know about the ignore function.

Out of scope

• Monadic expressions.
• Computation expressions.

Concepts

The Concepts this exercise unlocks are:

• expressions: know what expressions are; know how expressions are different from statements; know what pure functions are.
• unit: know what the unit type is; know about the ignore function.

Prerequisites

This exercise's prerequisites Concepts are:

• pattern-matching: know what a match expression is.
• conditionals: know what an if/elif/else expression is.

Any data types used in this exercise (e.g. strings) should also be added as prerequisites.

Resources to refer to

Hints

• Expressions vs statements: explains the differences between expressions and statements.
• unit type: describes the unit type.
• ignore function: shows the use of the ignore function.

After

• Expressions vs statements: explains the differences between expressions and statements.
• unit type: describes the unit type.
• ignore function: shows the use of the ignore function.

Representer

This exercise does not require any specific representation logic to be added to the representer.

Analyzer

This exercise does not require any specific logic to be added to the analyzer.

Implementing

To implement this exercise, please follow these instructions.

Help

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