Trait ChipInstances 

pub trait ChipInstances {
    // Required methods
    fn n_chips(&self) -> usize;
    fn n_instances(&self, chip_id: usize) -> usize;
    fn instance(&self, chip_id: usize, row: usize) -> Cow<'_, ValueVec>;
}

The chip instances of an M4 witness, addressed by chip ID and row.

ConstraintSystemM4::verify reads one instance at a time and never holds two, so this is all it needs of a witness. A witness that stores its instances packed — as the prover’s tables do, one column per instance — can therefore serve them one at a time rather than expanding the whole witness into value vectors first, which for a system of any size is most of its memory.

Instances are served, not lent, because a packed witness has to build one to hand it over. One that already holds value vectors lends them and pays nothing.

Required Methods

fn n_chips(&self) -> usize

The number of chips the witness covers, which must be the number the system has.

fn n_instances(&self, chip_id: usize) -> usize

The number of instances of the given chip, which must be at least its active-instance count.

fn instance(&self, chip_id: usize, row: usize) -> Cow<'_, ValueVec>

The value vector of one instance of one chip.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl ChipInstances for [Vec<ValueVec>]

fn n_chips(&self) -> usize

fn n_instances(&self, chip_id: usize) -> usize

fn instance(&self, chip_id: usize, row: usize) -> Cow<'_, ValueVec>

Implementors