nocter-diagnostics

Responsibility

Own the phase-neutral diagnostic envelope and deterministic human and JSON presentation of source-backed compiler failures. It consumes the closed diagnostic-code vocabulary from nocter-language, while the specification owns each code's public meaning and each compiler stage owns rule selection.

Contract

Each compiler stage selects its rule, supplies typed subjects through narrow origin contracts, and may attach a typed repair capability while it still owns the failed semantic evidence. The crate retains that phase-selected capability beside the diagnostic envelope and projects source for rendering; it does not rerun lookup, typing, target selection, or recovery policy.

nocter-language publishes DiagnosticCode from the compiler's explicit registered-code inventory. Production diagnostic APIs accept that closed vocabulary rather than arbitrary strings. Documentation generation compares the inventory with the public catalog in spec/tooling/diagnostics.md without searching Rust source text.

Internal Responsibilities

• stable codes, severity, labels, and notes
• syntax and semantic origin projection
• phase-selected semantic repair capabilities
• human-readable rendering
• machine-readable JSON rendering

Invariants

• One authored violation has one owning stage and stable diagnostic identity.
• An unregistered string cannot cross a compiler diagnostic boundary as a code.
• Rendering cannot change whether compilation succeeds.
• Missing source projection is an integrity failure, not permission to guess a range.
• A repair consumer cannot infer eligibility or authored evidence from a code, rendered message, or source substring.