made_core/value_objects/
discrimination.rs

1//! [`Discrimination`] — whether a scoring policy re-ordered the winner.
2//!
3//! The signal behind the judge-discrimination metric: does the policy's
4//! ranking pick a *different* winner than a structural baseline would, or
5//! does it merely confirm it? A policy that almost never reranks is
6//! expensive dead weight; one that always reranks is doing real work.
7
8/// How a scoring policy's winner compares to the structural baseline.
9#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
10pub enum Discrimination {
11    /// The policy picked a different winner than the baseline — it
12    /// changed the outcome.
13    Reranked,
14    /// The policy's winner is the same the baseline would pick.
15    Agreed,
16    /// The top score is shared by more than one proposal — the policy did
17    /// not separate the leaders.
18    Tie,
19}
20
21impl Discrimination {
22    /// Stable, low-cardinality label value for metrics exposition. Part
23    /// of the metric contract; dashboards match on it.
24    #[must_use]
25    pub const fn as_label(self) -> &'static str {
26        match self {
27            Self::Reranked => "reranked",
28            Self::Agreed => "agreed",
29            Self::Tie => "tie",
30        }
31    }
32}
33
34#[cfg(test)]
35mod tests {
36    use super::*;
37
38    #[test]
39    fn labels_are_distinct_and_stable() {
40        assert_eq!(Discrimination::Reranked.as_label(), "reranked");
41        assert_eq!(Discrimination::Agreed.as_label(), "agreed");
42        assert_eq!(Discrimination::Tie.as_label(), "tie");
43    }
44}
made_core/value_objects/discrimination.rs

made_core/value_objects/
discrimination.rs
