Struct Sign 

pub struct Sign<E: IntegerElement, Bd: Bound, const BLK: usize, K: SymbolCode = u16> { /* private fields */ }

Weights in {-1, +1}, one bit per element, with no table at all.

The Packed<Grid<2>,8> spelling of the same decode (CK-13) tabulates but can never answer Enumerable::as_index_stream: a packed byte’s index is a mixed-radix decomposition of it, so the tabulated traversal builds the index stream it gathers from. Measured, that build is a fifth to a third of the work at a one-row tile (ANALYSIS.md, “What the missing index stream costs the sign composition”). This tier spells the same decode with the code being the index — Code = u16, one bit per element of the block — so the operand’s own memory is the stream and there is nothing to build. CK-11 pins the two spellings byte for byte.

The codebook is the constant {-1, +1}, so there is nothing to borrow and no lifetime: the decode is a bit test. Bit t of the code is element t; set is +1, clear is -1, low bit first — the order Packed reads its sub-codes in (CK-03), so a Sign code spells the block the composition spells from the same byte value. The convention is normative: the encoder side is out of tree, and this decode is the whole contract with it.

Implementations

impl<E: IntegerElement, Bd: Bound, const BLK: usize, K: SymbolCode> Sign<E, Bd, BLK, K>

pub const fn new() -> Option<Self>

The one non-existence check: an alphabet that does not admit +-1 has no sign codec. Decided at construction, before any arithmetic, like every other non-existence in this library (C6).

Trait Implementations

impl<E: Clone + IntegerElement, Bd: Clone + Bound, const BLK: usize, K: Clone + SymbolCode> Clone for Sign<E, Bd, BLK, K>

fn clone(&self) -> Sign<E, Bd, BLK, K>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<E: IntegerElement, Bd: Bound, const BLK: usize, K: SymbolCode> Codec<E, Bd> for Sign<E, Bd, BLK, K>

const MAX_BLOCK: usize = BLK

The most alphabet elements one code can produce.

const TIER: TierId = TierId::Sign

Which tier this is, for reports and for the kappa manifest.

type Code = K

The stored code type.

fn decode_element(&self, code: Self::Code, i: usize) -> Alphabet<E, Bd>

Decode element i of the block code names. Total for every i.

const IS_FIXED_WIDTH: bool = true

Is decode_len always MAX_BLOCK?

fn decode_len(&self, _code: Self::Code) -> usize

How many elements code actually produces.

fn decode_into(&self, code: Self::Code, out: &mut [Alphabet<E, Bd>]) -> usize

Decode one code, returning how many elements were written.

fn decode_seq(&self, codes: &[Self::Code], out: &mut [Alphabet<E, Bd>]) -> usize

Bulk path, returning how many elements were written in total.

impl<E: Copy + IntegerElement, Bd: Copy + Bound, const BLK: usize, K: Copy + SymbolCode> Copy for Sign<E, Bd, BLK, K>

impl<E: Debug + IntegerElement, Bd: Debug + Bound, const BLK: usize, K: Debug + SymbolCode> Debug for Sign<E, Bd, BLK, K>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<E: IntegerElement, Bd: Bound, const BLK: usize, K: SymbolCode> Enumerable<E, Bd> for Sign<E, Bd, BLK, K>

const CODE_SPACE: usize

The number of distinct codes.

const SIGN_BIT_BOOK: bool = true

Whether the decoded book is the sign bit-decomposition: CODE_SPACE is a power of two and book[c][t] == 2 * bit(c, t) - 1 for every code c and every t below its log.

fn code_at(index: usize) -> Self::Code

The index-th code. Total for index < CODE_SPACE.

fn index_of(code: Self::Code) -> usize

Where code sits in the enumeration.

fn as_index_stream(codes: &[K]) -> Option<IndexStream<'_>>

The stored code stream, read as the index stream it already is.