Struct Lesson 

pub struct Lesson {
    pub id: String,
    pub title: String,
    pub description: String,
    pub difficulty: Difficulty,
    pub estimated_minutes: u32,
    pub steps: Vec<LessonStep>,
    pub prerequisites: Vec<String>,
    pub tags: Vec<String>,
    pub setup: Vec<SetupFile>,
}

A complete lesson module (e.g., “Navigation Basics”)

TOML lesson-pack format

Lessons can be authored as *.toml files (loaded from ~/.config/arct/lessons/ via LessonLibrary::load_from_dir). The top-level fields map 1:1 onto this struct:

id = "my-lesson"
title = "My Lesson"
description = "What this lesson teaches."
difficulty = "Beginner"          # Beginner | Intermediate | Advanced | Expert
estimated_minutes = 10
prerequisites = ["nav-basics"]   # lesson ids to complete first
tags = ["beginner", "files"]

# Optional starter files, materialized into the practice environment
# before the lesson starts (omit entirely if the lesson needs none).
# In simulated mode they are seeded into the virtual sandbox filesystem;
# in real practice mode they are written under
# ~/ArcAcademy/playground/<lesson-id>/ and the session cd's there.
# `path` is relative to the lesson's practice directory (subdirectories
# are created as needed; absolute paths and `..` are rejected).
[[setup]]
path = "notes.txt"
contents = "starter content\n"

[[setup]]
path = "logs/server.log"
contents = "line 1\nline 2\n"

[[steps]]
step_number = 1
title = "First step"
instruction = "Type the command..."
hint = "Try 'pwd'"

[steps.step_type.CommandExercise]
expected_command = "pwd"
validation = "CommandOnly"
success_message = "Nice!"

Fields

id: String

title: String

description: String

difficulty: Difficulty

estimated_minutes: u32

steps: Vec<LessonStep>

prerequisites: Vec<String>

tags: Vec<String>

setup: Vec<SetupFile>

Optional starter files for the lesson’s practice environment.

Defaults to empty, so existing lesson-pack TOML files without a setup array keep parsing unchanged.

Implementations

impl Lesson

pub fn to_toml(&self) -> Result<String>

Serialize this lesson to a TOML document (the on-disk lesson format).

pub fn from_toml(content: &str) -> Result<Self>

Parse a lesson from a TOML document.

Trait Implementations

impl Clone for Lesson

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Lesson

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Lesson

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Lesson

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.