fn boundary_constraint_from_periodic_assertion()

in air/src/air/boundary/tests.rs [70:118]

• 39 lines of code
• 1 McCabe index (conditional complexity)

fn boundary_constraint_from_periodic_assertion() {
    let mut test_prng = build_prng();
    let (inv_g, mut twiddle_map, mut prng) = build_constraint_params(16);

    // constraint should be built correctly for register 0, step 0, stride 4
    let value = rand_value::<BaseElement>();
    let assertion = Assertion::periodic(0, 0, 4, value);
    let constraint = BoundaryConstraint::<BaseElement, BaseElement>::new(
        assertion,
        inv_g,
        &mut twiddle_map,
        prng.draw_pair().unwrap(),
    );
    assert_eq!(0, constraint.register());
    assert_eq!(vec![value], constraint.poly());
    assert_eq!((0, BaseElement::ONE), constraint.poly_offset());
    assert_eq!(test_prng.draw_pair::<BaseElement>().unwrap(), constraint.cc);

    // periodic value constraints should evaluate to trace_value - value
    let trace_value = rand_value::<BaseElement>();
    assert_eq!(
        trace_value - value,
        constraint.evaluate_at(rand_value::<BaseElement>(), trace_value)
    );

    // constraint should be built correctly for register 2, first step 3, stride 8
    let value = rand_value::<BaseElement>();
    let assertion = Assertion::periodic(2, 3, 8, value);
    let constraint = BoundaryConstraint::<BaseElement, BaseElement>::new(
        assertion,
        inv_g,
        &mut twiddle_map,
        prng.draw_pair().unwrap(),
    );
    assert_eq!(2, constraint.register());
    assert_eq!(vec![value], constraint.poly());
    assert_eq!((0, BaseElement::ONE), constraint.poly_offset());
    assert_eq!(test_prng.draw_pair::<BaseElement>().unwrap(), constraint.cc);

    // periodic value constraints should evaluate to trace_value - value
    let trace_value = rand_value::<BaseElement>();
    assert_eq!(
        trace_value - value,
        constraint.evaluate_at(rand_value::<BaseElement>(), trace_value)
    );

    // twiddle map was not touched
    assert!(twiddle_map.is_empty());
}