Struct Exercise 

pub struct Exercise {
    pub id: &'static str,
    pub kind: ExerciseKind,
    pub concepts: &'static [&'static str],
    pub prompt: &'static str,
    pub mode: ExampleMode,
    pub expected: &'static str,
    pub starter: &'static str,
    pub hints: &'static [&'static str],
    pub reference: &'static str,
}

A “now you try” challenge: the reader writes code (Imperative — graded by exact program output), a page (Web — graded by its own ## Test blocks) or FOL (Logic — graded structurally by the Learn grader), right in the guide.

Fields

id: &'static str

kind: ExerciseKind

Where this sits on the fading ladder.

concepts: &'static [&'static str]

The LANGUAGE_SURFACE features this practices (deliberate practice targets the hard part; checkpoints interleave via these).

prompt: &'static str

The task, stated to the reader.

mode: ExampleMode

expected: &'static str

The graded target: exact output lines (Imperative) or the expected FOL. Empty for a Web exercise, which is graded by the ## Test blocks its page carries.

starter: &'static str

Pre-filled editor contents.

hints: &'static [&'static str]

1–3 progressive hints, disclosed on demand: orient, then narrow — never the answer (Bloom’s corrective tutor).

reference: &'static str

The hidden answer key — the self-check lock proves it grades correct.

Trait Implementations

impl Clone for Exercise

fn clone(&self) -> Exercise

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Exercise

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

Formats the value using the given formatter.

impl PartialEq for Exercise

fn eq(&self, other: &Exercise) -> 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 StructuralPartialEq for Exercise