Crate duck_diag 

Generic diagnostic engine for tools that need rich, rustc-style error output. Plug in your own error code enum, attach spans + labels + suggestions, and render in pretty (color), plain, or JSON modes.

See examples/ for end-to-end demos.

Macros

diag

Shorthand for Diagnostic::new(...) with optional label/note/help/suggestion.

Structs

Diagnostic

One error / warning / note carrying a code, message, labels, notes, help, and suggestions.

DiagnosticEngine

Collects diagnostics, tracks per-severity counts, and renders them in pretty / plain / compact / JSON modes.

DiagnosticFormatter

Renders one diagnostic at a time. Holds a borrowed (or owned) line cache plus the active RenderOptions.

Label

A span + optional message + optional per-caret note. Multiple labels per diagnostic stack rustc-style.

RenderOptions

Tunables for rendered output.

SourceCache

Pre-split source cache. Build once per source string, reuse for many diagnostics.

Span

Source span.

Suggestion

Code rewrite suggestion attached to a diagnostic.

Enums

Applicability

How confident the suggestion is — controls whether IDEs may auto-apply it.

LabelStyle

Caret style for a label. Primary underlines with ^, Secondary with -.

Severity

Severity of a diagnostic.

Traits

DiagnosticCode

Implement this on your error enum to plug into the diagnostic system.

Functions

format_all_smart

Format every diagnostic in engine to a single string, picking with-source vs compact rendering per diagnostic. Trailing summary line included.

format_compact

Render a single diagnostic in compact (source-less) form.

print_all_smart

Print every diagnostic in engine to stderr, picking with-source vs compact rendering per diagnostic. color = None → auto-detect via std::io::stderr().is_terminal(). Trailing summary line included.