Module string_layer 

String layer — KeyCard ↔ Vec<String> (BCH + chunked-header reassembly).

Wraps the bytecode-layer codec (crate::bytecode) with the BIP 93–derived BCH error-correction layer (forked from md-codec per design/DECISIONS.md D-13) and the closure-locked string-layer header structure (per Q-5 — 2-symbol single-string + 8-symbol chunked).

Submodules:

• bch: BCH polymod, syndrome decoder, and bech32-alphabet helpers.
• bch_decode: syndrome-based BM/Forney decoder (impl detail of bch). pub(crate) for cross-module test fixture access; not part of the user-facing API.
• header: 5-bit-symbol-aligned StringLayerHeader (SingleString + Chunked variants).
• chunk: stream split + reassemble with cross_chunk_hash integrity check.

The public entry points wired up here (encode / encode_with_chunk_set_id / decode) are the layer-3 boundary; crate::key_card re-exports them.

Re-exports

pub use bch::ALPHABET;

pub use bch::BchCode;

pub use bch::CaseStatus;

pub use bch::CorrectionResult;

pub use bch::DecodedString;

pub use bch::SEPARATOR;

pub use bch::bch_correct_long;

pub use bch::bch_correct_regular;

pub use bch::bch_create_checksum_long;

pub use bch::bch_create_checksum_regular;

pub use bch::bch_verify_long;

pub use bch::bch_verify_regular;

pub use bch::bytes_to_5bit;

pub use bch::case_check;

pub use bch::decode_string;

pub use bch::encode_5bit_to_string;

pub use bch::five_bit_to_bytes;

pub use bch::hrp_expand;

pub use chunk::reassemble_from_chunks;

pub use chunk::split_into_chunks;

pub use header::StringLayerHeader;

Modules

bch

BCH primitives for the mk1 string layer: bech32 alphabet conversion and syndrome-based error correction.

bch_decode

Syndrome-based BCH decoder for the MK regular and long codes.

chunk

Stream chunking + cross-chunk integrity hash for mk1 multi-string cards.

header

5-bit-symbol-aligned string-layer header (single-string + chunked variants).

Functions

decode

Decode one or more mk1-prefixed strings into a KeyCard.

encode

Encode a KeyCard into one or more mk1-prefixed strings.

encode_with_chunk_set_id

Like encode, but with an explicit chunk_set_id override.