Struct Packed 

pub struct Packed<'a> { /* private fields */ }

The bits of a packed vector and what they mean, for a kernel that wants to stay in code space.

Borrowed from the vector rather than owning anything, so getting one costs nothing and a kernel that finds it cannot use them has given up nothing by asking.

Implementations

impl Packed<'_>

pub fn width(&self) -> u32

How many bits one code takes, between one and PACKED_WIDTH_MAX.

pub fn base(&self) -> i128

What zero means, so that the value of a row is the base plus its code.

pub fn ceiling(&self) -> i128

The largest value this vector can be holding, whatever it is actually holding.

With Self::base this is the pair a comparison kernel wants first. A literal outside the two answers every row of the vector the same way, which is a whole chunk decided without a bit being read, and that is the case a zone map would have caught if there were one here.

pub fn code(&self, row: usize) -> u64

The code of row row, which is its value minus Self::base.

Out of range rows read as zero rather than panicking, the way every other accessor in this file answers for a row that is not there.

pub fn code_of(&self, value: i128) -> Option<u64>

Which code a value would have, and None for a value this vector cannot be holding.

The translation a comparison does once per vector so that it does not have to unpack once per row. None is the useful answer rather than a failure: it says the literal is outside the packed range, so every row compares against it the same way.

Trait Implementations

impl<'a> Clone for Packed<'a>

fn clone(&self) -> Packed<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for Packed<'a>

impl<'a> Debug for Packed<'a>

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

Formats the value using the given formatter.