Module diag 

Source-located diagnostics with stable codes (ADR-0009, TECH-SPEC §9).

The core produces structured Diags; only proef-cli renders them (miette stays out of library crates). Every diagnostic carries a stable, greppable code (proef::pack::adjacent_captures, …) — the seeded error corpus names one file per code (TESTING-STRATEGY §4).

Spans are 0-based byte offsets, end-exclusive — directly convertible to miette’s SourceSpan. Gherkin span caveats (trailing-newline normalization, char-counted LineCol) are handled where spans are produced, never here.

Structs

Diag

One structured, source-located finding.

Span

A byte span into a source text (0-based, end-exclusive).

Enums

FrontError

Outcome of a front-end stage: diagnostics (user fault, exit 2 when any is an error) or a non-diagnostic core failure.

Severity

Diagnostic severity.