Trait ark_r1cs_std::select::ThreeBitCondNegLookupGadget[−][src]

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>;
}
Expand description

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

Associated Types

The type of values being looked up.

Required methods

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