Trait ark_r1cs_std::select::TwoBitLookupGadget

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

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

Performs a lookup in a 4-element table using two bits.

Required Associated Types

type TableConstant

The type of values being looked up.

Required Methods

fn two_bit_lookup(
    bits: &[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].

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

Panics

This method panics if bits.len() != 2 or constants.len() != 4.

Implementors

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

type TableConstant = CubicExtField<P>

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

type TableConstant = QuadExtField<P>

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

Uses two bits to perform a lookup into a table b is little-endian: b[0] is LSB.

type TableConstant = F

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

Uses two bits to perform a lookup into a table b is little-endian: b[0] is LSB.

type TableConstant = F

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

Uses two bits to perform a lookup into a table b is little-endian: b[0] is LSB.

type TableConstant = TargetField

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

type TableConstant = TargetField