Struct Lesson 

pub struct Lesson {
    pub lesson_name: LessonId,
    pub language: Language,
    pub exercise: Exercise,
    pub checks: Vec<String>,
    pub packages: Vec<String>,
    pub description: Option<String>,
    pub textbook_reference: Option<String>,
}

A single lesson: its identity, language, and exercise, with optional prose.

Construct one only through Lesson::parse — a value of this type is, by construction, structurally complete and semantically valid (ADR-0003).

Fields

lesson_name: LessonId

The lesson’s identity (v1: its name). Required.

language: Language

The language the lesson is authored in. Required.

exercise: Exercise

The exercise the lesson poses. Required.

checks: Vec<String>

Executable check code-strings, run against a submission in the lesson’s language to grade it (Slice 9). A Vec defaulting to empty, not an Option<Vec>: “no checks” is just the empty list, so there is no redundant null state forcing absence-handling downstream (§1.1). A lesson graded by the LLM alone (the R package’s model) therefore needs no checks key, and every existing lesson stays valid.

packages: Vec<String>

Third-party packages the lesson’s code depends on (e.g. pandas, purrr). A Vec defaulting to empty, not an Option<Vec>: “no packages” is just the empty list, mirroring checks (§1.1). A lesson with no packages key stays valid; the browser runner receives an empty array and the local Python runner spawns uv run with no --with flags (ADR-0011).

description: Option<String>

Optional one-line summary.

textbook_reference: Option<String>

Optional pointer to a textbook section.

Implementations

impl Lesson

pub fn parse(yaml: &str) -> Result<Lesson, ValidationError>

Parse a lesson from a YAML document.

The pure parse boundary (§2.1, §1.3.1): it deserializes the document into the typed model — a missing required field or wrong type yields ValidationError::Parse naming the field — then runs validate_semantics for the rules structure alone cannot express. Returns a Lesson only if both succeed.

Trait Implementations

impl Clone for Lesson

fn clone(&self) -> Lesson

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 PartialEq for Lesson

fn eq(&self, other: &Lesson) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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.

impl Eq for Lesson

impl StructuralPartialEq for Lesson