Implement new Concept Exercise: memory-allocation

Start by reading languages/fsharp/reference/implementing-a-concept-exercise.md and comparing languages/fsharp/exercises/concept/numbers/.meta/design.md and .meta/config.json with the linked v3 guidance. Use reference/concepts/memory-allocation.md and the listed learning objectives to shape the exercise, then confirm the completed exercise and metadata follow the F# track conventions.

This issue describes how to implement the memory-allocation 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 Memory Allocation in F#.

Learning objectives

• Know what the stack and heap are.
• Know what the garbage collector is.
• Know how the stack and heap are different.
• Know what the large object heap is.
• Know what reference and value types are.
• Know how reference and value types relate to the stack and heap.
• Know how to make a discriminated union, record, tuple or class a struct.

Out of scope

• Memory locality.
• Memory pooling.
• Pointer semantics.
• Span<T> and Memory<T>
• Readonly semantics and by reference arguments.
• Discussion of profiling tools (referring to them is fine).

Concepts

The Concepts this exercise unlocks are:

• memory-allocation: know what the stack and heap are; know what the garbage collector is; know how the stack and heap are different; know what the large object heap is; know what reference and value types are; know how reference and value types relate to the stack and heap; know how to make a discriminated union, record, tuple or class a struct.

Prerequisites

This exercise's prerequisites Concepts are:

• classes: know how to define a class.
• records: know how to define a record.
• tuples: know how to define a tuple.
• discriminated-unions: know how to define a discriminated union.
• attributes: know how to add attributes.

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

Resources to refer to

Hints

• Structs: describes what structs are and how to define a type (class) as a struct
• Struct tuples: how to define struct tuples.
• Struct records: how to define struct records.
• Struct discriminated unions: how to define struct discriminated unions.

The following links all use C# as their language, but the concepts apply equally as well to F#:

• Value types: introduction to value types.
• Reference types: introduction to reference types.
• Stack versus heap: how the stack and heap work.

After

• Structs: describes what structs are and how to define a type (class) as a struct
• Struct tuples: how to define struct tuples.
• Struct records: how to define struct records.
• Struct discriminated unions: how to define struct discriminated unions.

The following links all use C# as their language, but the concepts apply equally as well to F#:

• Value types: introduction to value types.
• Reference types: introduction to reference types.
• Stack versus heap: how the stack and heap work.
• Value types vs reference types: in-depth comparison between value and reference types
• Garbage collection: how garbage collection works in C#.
• Large Object Heap: what the Large Object Heap is.
• Garbage collection performance: in-depth look into garbage collection performance.

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.