duck-diag 0.8.1

Renamed from duck-diagnostic (0.7.x). New publishing line: duck-diag 0.8+. Old crate stays on crates.io for compatibility.

Install

cargo add duck-diag

Optional json feature (default on):

[dependencies]
duck-diag = { version = "0.8", features = ["json"] }

Quick start

use duck_diag::{Diagnostic, Label, Severity, diag};

let d = diag!(Severity::Error, "type mismatch")
  .with_label(Label::primary(span, Some("expected i32, found String".into())))
  .with_help("convert with `as i32` or change the binding type");

d.print();      // pretty terminal output
let json = d.to_json();   // stable JSON shape (with `json` feature)

Module matrix

path	role
`src/diagnostic.rs`	`Diagnostic`, `Label`, `Span`, `Severity`, `Suggestion`, `Applicability`
`src/formatter.rs`	terminal formatter with caret rendering, color, tab/Unicode-width handling
`src/smart.rs`	multi-file smart printer
`src/compact.rs`	source-less compact rendering + style helpers
`src/json.rs`	stable JSON schema (feature `json`)
`src/style.rs`	`RenderOptions`, color toggles, line width clamps
`src/macros.rs`	`diag!` macro

Why a generic engine

Most Rust tools (compilers, linters, schema validators, SQL parsers) want the same diagnostic shape: severity + message + labels + spans + hints. duck-diag gives you that surface without pulling in miette, ariadne, or syn. Useful when you want a tiny dep that ships color + caret rendering without the rest of the world.

Build

cargo build --release
cargo test  --workspace

Used by

crate	how
`@gentleduck/md` (dmc)	every layer's diagnostic engine
your tool here	open a PR against this README

Contributing

PR checklist + style notes in CONTRIBUTING.md. Security: SECURITY.md. Behaviour: CODE_OF_CONDUCT.md.

License

MIT. See LICENSE.