Metrics catalog
Metrics are facts with definitions, not an implied ranking of grammar quality. Each metric has a scope and interpretation context.
| Group | Examples | Typical class |
|---|---|---|
| Size | rules, alternatives, terminals | A |
| Structure | reachable, recursive, productive rules | A or B |
| Representation | ordered choice, EBNF sugar, precedence | B or C |
| Review signals | unresolved symbols, diagnostics | A for the same policy |
The complete definitions, nullability rules, and notApplicable cases are in the normative metrics catalog. Cross-format guidance is in the cross-format notes.
Do not render notApplicable as zero. Do not compare Class B or C values without preserving frontend capabilities and representation context.