bits (DXN.md §1.4): a run of bits that is not whole bytes, written
as its bytes and their bit count -- @bits {"oA==" 3} in text,
T_BITS around [bytes, count] in .dxnb.
Bits and bytes are one value space. An Elixir bitstring is the
value, held in a Dextrin.Bytes like any bytes; one whose size is a
multiple of 8 is a binary, and is written as bytes. This module is the
one place the two halves of the written form are made and checked, so
text, binary and the canonical form cannot disagree about them.
Summary
Functions
The bits data and count write, or :error when they do not write
any: count must be a non-negative integer and data exactly the
bytes it needs. The unused low bits of the last byte are ignored.
bits as written: its bytes, the unused low bits of the last one
zero, and how many of their bits are the value.
Functions
The bits data and count write, or :error when they do not write
any: count must be a non-negative integer and data exactly the
bytes it needs. The unused low bits of the last byte are ignored.
iex> Dextrin.Bits.from_parts(<<0b10100111>>, 3)
{:ok, <<5::3>>}
iex> Dextrin.Bits.from_parts(<<1, 2>>, 3)
:error@spec parts(bitstring()) :: {binary(), non_neg_integer()}
bits as written: its bytes, the unused low bits of the last one
zero, and how many of their bits are the value.
iex> Dextrin.Bits.parts(<<5::3>>)
{<<0b10100000>>, 3}