Trait Scoreable 

pub trait Scoreable: Send + Sync {
    // Required methods
    fn id(&self) -> &str;
    fn score_proxy(&self) -> f32;
    fn category(&self) -> &str;
    fn metadata(&self) -> &HashMap<String, String>;

    // Provided method
    fn prerequisites(&self) -> &[String] { ... }
}

Trait that caller’s item type must implement.

The engine only needs three things from any item:

• a stable unique ID
• a normalised score proxy (0.0–1.0) used by built-in factors (difficulty in learning, price_ratio in ecommerce, remoteness in travel…)
• a category/topic string for coverage factor

All other domain data lives in metadata() — accessible to custom factors.

Required Methods

fn id(&self) -> &str

fn score_proxy(&self) -> f32

Normalised difficulty/complexity proxy. Range [0.0, 1.0]. Caller defines what this means in their domain.

fn category(&self) -> &str

Category label used for coverage balancing. e.g. “algebra”, “electronics”, “beach”, “thriller”

fn metadata(&self) -> &HashMap<String, String>

Arbitrary key-value metadata for custom factor logic.

Provided Methods

fn prerequisites(&self) -> &[String]

Prerequisite item IDs. Engine will not suggest this item until all prereqs appear in the user’s resolved_set.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Scoreable for Item