Trait ark_r1cs_std::select::ThreeBitCondNegLookupGadget

pub trait ThreeBitCondNegLookupGadget<ConstraintF: Field>where
    Self: Sized,{
    type TableConstant;

    fn three_bit_cond_neg_lookup(
        bits: &[Boolean<ConstraintF>],
        b0b1: &Boolean<ConstraintF>,
        constants: &[Self::TableConstant]
    ) -> Result<Self, SynthesisError>;
}

Uses three bits to perform a lookup into a table, where the last bit conditionally negates the looked-up value.

Required Associated Types

type TableConstant

The type of values being looked up.

Required Methods

fn three_bit_cond_neg_lookup(
    bits: &[Boolean<ConstraintF>],
    b0b1: &Boolean<ConstraintF>,
    constants: &[Self::TableConstant]
) -> Result<Self, SynthesisError>

Interprets the slice bits as a two-bit integer b = bits[0] + (bits[1] << 1), and then outputs constants[b] * c, where c = if bits[2] { -1 } else { 1 };.

That is, bits[2] conditionally negates the looked-up value.

For example, if bits == [1, 0, 1], and constants == [0, 1, 2, 3], this method should output a variable corresponding to -1.

Panics

This method panics if bits.len() != 3 or constants.len() != 4.

Implementors

impl<BF, P> ThreeBitCondNegLookupGadget<<P as CubicExtConfig>::BasePrimeField> for CubicExtVar<BF, P>where
    BF: FieldVar<P::BaseField, P::BasePrimeField> + ThreeBitCondNegLookupGadget<P::BasePrimeField, TableConstant = P::BaseField>,
    for<'a> &'a BF: FieldOpsBounds<'a, P::BaseField, BF>,
    P: CubicExtVarConfig<BF>,

type TableConstant = CubicExtField<P>

impl<BF, P> ThreeBitCondNegLookupGadget<<P as QuadExtConfig>::BasePrimeField> for QuadExtVar<BF, P>where
    BF: FieldVar<P::BaseField, P::BasePrimeField> + ThreeBitCondNegLookupGadget<P::BasePrimeField, TableConstant = P::BaseField>,
    for<'b> &'b BF: FieldOpsBounds<'b, P::BaseField, BF>,
    P: QuadExtVarConfig<BF>,

type TableConstant = QuadExtField<P>

impl<F: PrimeField> ThreeBitCondNegLookupGadget<F> for FpVar<F>

type TableConstant = F

impl<F: PrimeField> ThreeBitCondNegLookupGadget<F> for AllocatedFp<F>

type TableConstant = F

impl<TargetField: PrimeField, BaseField: PrimeField> ThreeBitCondNegLookupGadget<BaseField> for NonNativeFieldVar<TargetField, BaseField>

type TableConstant = TargetField

impl<TargetField: PrimeField, BaseField: PrimeField> ThreeBitCondNegLookupGadget<BaseField> for AllocatedNonNativeFieldVar<TargetField, BaseField>

type TableConstant = TargetField