天衡 / tianheng

懸衡以待,失衡即應。 — Hold the balance ready; react the moment it tips.

The shell of the Tianheng crate family: reactive architectural governance that weighs the shape you declared against the shape the code is, and reacts the moment they no longer balance. Govern by reaction, not instruction.

天衡 (the celestial balance) is the imperative shell + facade — CLI (arg parsing, filesystem, stdout/stderr) and the run reaction that composes every dimension into one. You declare a single Constitution carrying all 三儀 (the three instruments) and call run:

use tianheng::prelude::*;

// One declared constitution carries every dimension — the single source of truth.
fn constitution() -> Constitution {
    Constitution::new("my-project")
        // 圭表 (static): imports & dependencies
        .boundary(
            CrateBoundary::crate_("my-core")
                .deny_external_dependencies()
                .because("my-core must stay dependency-light"),
        )
        // 渾儀 (semantic): folded in via typed adders, e.g.
        // .signature_boundary(SemanticBoundary::in_crate("my-app")…)
        // 漏刻 (runtime): a declared seam, audited for probe coverage at CI
        // .runtime(RuntimeBoundary::at("domain-entry").only_origins(["my_app::domain"]).because(…))
}

fn main() -> std::process::ExitCode {
    // One declaration in; the 三儀 compose into the one reaction.
    tianheng::run(&constitution(), std::env::args())
}

your-binary check --manifest-path path/to/Cargo.toml reacts against your constitution: exit 0 (clean / warn-only / fully baselined), 1 (enforced violation), 2 (constitution/scan error). list projects the declared constitution and never reacts. check --format json projects the reaction as JSON (the machine contract); --format sarif emits a vendor-neutral SARIF 2.1.0 document for CI code-scanning. The violation's reason is the repair direction; the human text report and the Markdown projection lead with it.

The instruments (三儀)

tianheng composes the three observation dimensions, each its own crate, each real drift (declared vs. observed) — never a style lint:

Beneath them sits xuanji — the dimension-agnostic reaction model. The 漏刻 prod face is wired in your own binary (louke::install(constitution().runtime_boundaries()…)); its CI probe-coverage face is run by tianheng check.

The published tianheng binary is a demo bound to a sample constitution (it governs a crate named example-core). Tianheng is consumed as a library: declare your own constitution and expose your own binary, as above.

Tianheng governs itself with its own reaction (crates/tianheng/tests/self_governance.rs): the core must not depend on the shell, syn is quarantined to hunyi, xuanji stays beneath every dimension.

License

Licensed under either of Apache-2.0 or MIT, at your option.