Struct CubeProjectionWitness 

pub struct CubeProjectionWitness<const FROM_DIMS: usize, const TO_DIMS: usize> { /* private fields */ }

Witness that a projection was performed along a named set of cube dimensions.

What this is

A zero-cost shape recording that a projection reduced FROM_DIMS original cube dimensions down to TO_DIMS projected dimensions. This is the receipt shape for a projection step — it names that a projection happened and what the arity reduction was.

What this is not

Not the projection computation. The engine produces this shape; this crate only defines the shape and validates its structural invariants.

Graduate to wasm4pm

The actual projection computation (sub-log extraction and merging along the dropped dimensions) graduates to wasm4pm.

Examples

use wasm4pm_compat::process_cube::CubeProjectionWitness;
let _w: CubeProjectionWitness<3, 2> = CubeProjectionWitness::new();

Implementations

impl<const FROM_DIMS: usize, const TO_DIMS: usize> CubeProjectionWitness<FROM_DIMS, TO_DIMS>

pub fn new() -> Self

Construct a new CubeProjectionWitness shape marker.

Examples

use wasm4pm_compat::process_cube::CubeProjectionWitness;
let w: CubeProjectionWitness<4, 2> = CubeProjectionWitness::new();
assert_eq!(w.from_dims(), 4);
assert_eq!(w.to_dims(), 2);

pub const fn from_dims(&self) -> usize

The number of dimensions before the projection.

pub const fn to_dims(&self) -> usize

The number of dimensions after the projection.

Trait Implementations

impl<const FROM_DIMS: usize, const TO_DIMS: usize> Default for CubeProjectionWitness<FROM_DIMS, TO_DIMS>

fn default() -> Self

Returns the “default value” for a type.