qec-code

qec-code provides Rust data structures and algorithms for constructing and analyzing quantum error-correcting codes. Its dependency-facing APIs include:

• CSS matrix validation and construction;
• exact distance through optional HiGHS or Gurobi ILP backends;
• randomized CSS distance upper bounds; and
• packed GF(2) row operations, reduced row spaces, and reusable kernel workspaces under qec_code::packed_gf2.

Installation

Add the library from crates.io:

[dependencies]
qec-code = "0.3.0"

Enable the open-source exact ILP backend only when it is needed:

qec-code = { version = "0.3.0", features = ["distance-ilp-highs"] }

The default build is a library-only build with no command-line parser or native solver dependency. Available opt-in features are:

• cli exposes qec_code::cli and builds the qec-code binary;
• distance-ilp-highs enables exact distance with HiGHS; and
• distance-ilp-gurobi enables exact distance with Gurobi without also pulling in HiGHS.

Applications that previously invoked the package binary or imported qec_code::cli must add features = ["cli"]. Features compose, so a CLI using HiGHS can enable both cli and distance-ilp-highs.

This crate is covered by the repository-wide Apache-2.0 license, which is also declared in the workspace package metadata. Enable the distance features above only when needed.

Deterministic regular matrices

qec_code::regular_classical provides the versioned pure-Rust generator for regular binary parity-check matrices used by random code families. The exact version-1 stream, bounded-index rule, retry behavior, and seed-7 fixture are documented in doc/regular_classical.md.

Packed GF(2) example

use qec_code::packed_gf2::{PackedRow, ReducedRowSpace};

let generators = vec![vec![1, 1, 0], vec![0, 1, 1]];
let space = ReducedRowSpace::from_dense_rows(&generators, 3)?;
let target = PackedRow::from_dense(&[1, 0, 1])?;
assert!(space.contains(&target)?);
# Ok::<(), qec_code::QecError>(())

The public wrappers intentionally hide the packed storage layout so internal elimination code can evolve without breaking downstream crates.