Module bitarray 

BitArray Module

A sequence-of-bits type with multiple backends, designed as a reusable bit-array library that flexfloat happens to be the first consumer of.

What this is

A dynamically-sized, little-endian sequence of bits backed by a pluggable storage implementation. The module defines a layered trait hierarchy so consumers can depend on only the capability they actually need.

Trait composition

Trait	Responsibility
BitArrayAccess	Read bits, query length, extract ranges
BitArrayMutAccess	Mutable bit access via GAT handle
BitArrayConstruction	Factory methods (from_bits, from_bytes, …)
BitArrayConversion	Serialisation (to_bits, to_bytes, to_biguint, …)
BitArrayManipulation	High-level in-place / consuming transforms
BitArray	Umbrella: all of the above + Debug + Clone + Default + PartialEq + Eq
BitArrayArith	Extends BitArray with Add + Sub + Mul + Div (bignum semantics)

Depend on the smallest set you need. FlexFloat<B> bounds most of its API on B: BitArray; arithmetic operations additionally require B: BitArrayArith.

Backends

• BoolBitArray — Vec<bool> storage, one byte per bit. Slow but easy to inspect; ideal for debugging and unit tests. This is also the DefaultBitArray.
• UsizeBitArray — word-packed storage. Faster for large widths.
• StaticBitArray<N> — const-generic, compile-time bit array. Zero overhead for constants, but read-only and no arithmetic. Ideal for const contexts and FlexFloat constant definitions.

Writing your own backend

Implement [backend::BitArrayPrimitives] plus the access, construction, and conversion traits; the high-level BitArrayManipulation default impls will be provided automatically.

Extension traits

BitArrayArith is optional. A bit-array implementation that only needs to be used as a set or bitmap does not need to provide arithmetic.

Stability

This module will be extracted into a standalone flexfloat-bitarray crate at 1.0. Nothing inside bitarray::* depends on flexfloat::*, so the split will be mechanical. The backend submodule contents are pub but #[doc(hidden)]; they will become a stable extension point in the new crate.

Re-exports

pub use bit_ref::BitRef;

pub use boolean_list::BoolBitArray;

pub use static_bit_array::StaticBitArray;

pub use traits::BitArray;

pub use traits::BitArrayArith;

pub use usize_list::UsizeBitArray;

pub use traits::BitArrayAccess;

pub use traits::BitArrayConstruction;

pub use traits::BitArrayConversion;

pub use traits::BitArrayManipulation;

pub use traits::BitArrayMutAccess;

Modules

bit_ref

A proxy reference to a single bit in packed bit storage.

boolean_list

Boolean List Implementation

static_bit_array

Const-generic static bit array backend.

traits

Traits module for BitArray implementations.

usize_list

Type Aliases

DefaultBitArray

Default BitArray implementation for general use in 1.x.