Concept: Random

[jiegillet]

Design

Goal

The Goal is to learn to use the Random module.

Learning objectives

Students should be able to

• understand the constraints of a pure language when it comes to generating randomness (mention step, Seed)
• understand what a generator is
• create primitive generators (int, float, constant)
• pick a distribution (uniform, weighted)
• generate data structures (list, pair)
• modify and intricate generators (map, andThen)
• define recursive generators (lazy)

Out of scope

• generate, Platform and Cmd msg (a quick mention is fine)
• details on the algorithm, minInt and maxInt

Concepts

The concept this exercise unlocks is:

• random

Prerequisites

• basics-1
• basics-2
• lists
• custom types

Analyzer

TBD depending on the exercise

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Comments

• The exercise should go beyond the usual "pick a thing from a list" and highlight the power of generators, for example building a recursive data structure (maze? family tree? Elm program?...)
• Test the exercise using seed and steps, in such a manner that students can also use it to debug their code.
• mention elm-community/random-extra has a lot of useful resources