Trait SumcheckEvaluator

pub trait SumcheckEvaluator<P: PackedField, Composition> {
    // Required methods
    fn eval_point_indices(&self) -> Range<usize>;
    fn process_subcube_at_eval_point(
        &self,
        subcube_vars: usize,
        subcube_index: usize,
        is_infinity_point: bool,
        batch_query: &RowsBatchRef<'_, P>,
    ) -> P;
    fn composition(&self) -> &Composition;
    fn eq_ind_partial_eval(&self) -> Option<&[P]>;

    // Provided methods
    fn process_constant_eval_suffix(
        &self,
        _const_eval_suffix: usize,
        _is_infinity_point: bool,
    ) -> P::Scalar { ... }
    fn const_eval_suffix(&self) -> usize { ... }
}

Required Methods

fn eval_point_indices(&self) -> Range<usize>

The range of eval point indices over which composition evaluation and summation should happen. Returned range must equal the result of n_round_evals() in length.

fn process_subcube_at_eval_point( &self, subcube_vars: usize, subcube_index: usize, is_infinity_point: bool, batch_query: &RowsBatchRef<'_, P>, ) -> P

Compute composition evals over a subcube.

batch_query should contain multilinears evals over a subcube represented by subcube_vars and subcube_index.

See doc comments to EvaluationDomain for the intuition behind is_infinity_point.

Returns a packed sum (which may be spread across scalars).

fn composition(&self) -> &Composition

Returns the composition evaluated by this object.

fn eq_ind_partial_eval(&self) -> Option<&[P]>

In case of zerocheck returns eq_ind that the results should be folded with. In case of sumcheck returns None.

Provided Methods

fn process_constant_eval_suffix( &self, _const_eval_suffix: usize, _is_infinity_point: bool, ) -> P::Scalar

Compute sum of evals over the suffix where the composite is guaranteed to evaluate to a constant.

It is assumed that all required inputs are known at the evaluator creation time, as const_eval_suffix is determined dynamically by the sumcheck round calculator and may be smaller than the return value of the method with the same name.

See doc comments to EvaluationDomain for the intuition behind is_infinity_point.

fn const_eval_suffix(&self) -> usize

Trace suffix where the composite is guaranteed to evaluate to a constant. The non-constant prefix would get processed via process_subcube_at_eval_point, whereas the remainder gets handled via process_constant_eval_suffix. Due to the fact that sumcheck operates over whole subcubes the const_eval_suffix passed to process_constant_eval_suffix may be smaller that the return value of this method.

Implementors