kip

Pure, thread-safe engineering expression evaluator for US imperial units, with exact rational arithmetic, partial (symbolic) evaluation, empirical code equations, and a user-extensible unit registry.

Status: 0.1.0 — M0–M8 complete (lexer through release hardening).

use kip::{eval, parse, RegistryBuilder, EmptyResolver};

let reg = RegistryBuilder::from_seed().freeze();
let expr = parse("12 ft - 6 in", &reg).unwrap();
let value = eval(expr.as_ref(), &reg, &EmptyResolver).unwrap();
println!("{}", value.quantity().unwrap().display(&reg, &kip::FmtOptions::calc_sheet()));

Three load-bearing requirements

1. P1 — Parallel branch evaluation. Immutable ASTs, registries, and pure evaluation — no globals, no locks.
2. P2 — Empirical engineering expressions as default. Code equations (ACI.fr(fc: f'c, lambda: 1.0)) are the main road.
3. P3 — User-defined units anchored to inch, lbf, second, Rankine (plus angle and custom base dimensions).

Force-based system

kip uses a force-based (gravitational) dimensional system common in structural engineering: Force is fundamental (lbf), mass is derived (slug = lbf·s²/ft). There is no hidden gc in user-visible math. SI-trained users: do not expect mass to be fundamental here.

Quick start

[dependencies]
kip = "0.1.0"

use kip::RegistryBuilder;

let mut b = RegistryBuilder::from_seed();
b.parse_defs("define tonf, tons = 2000 lbf").unwrap();
let reg = b.freeze();

Features

Examples

• examples/sheet.rs — topo-sort host pattern with eval_batch
• examples/sweep.rs — partial eval + parallel Value::bind sweep

Development

cargo test --all-features
cargo bench                    # criterion throughput + parallel scaling
cd fuzz && cargo fuzz run fuzz_lexer -- -runs=2048

See VERSIONING.md for release policy.

License

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