1use crate::prelude::*;
 2use algebra::Field;
 3use r1cs_core::SynthesisError;
 4
 5/// If condition is `true`, return `true_value`; else, select `false_value`.
 6pub trait CondSelectGadget<ConstraintF: Field>
 7where
 8    Self: Sized,
 9{
10    fn conditionally_select(
11        cond: &Boolean<ConstraintF>,
12        true_value: &Self,
13        false_value: &Self,
14    ) -> Result<Self, SynthesisError>;
15}
16
17/// Uses two bits to perform a lookup into a table
18pub trait TwoBitLookupGadget<ConstraintF: Field>
19where
20    Self: Sized,
21{
22    type TableConstant;
23    fn two_bit_lookup(
24        bits: &[Boolean<ConstraintF>],
25        constants: &[Self::TableConstant],
26    ) -> Result<Self, SynthesisError>;
27}
28
29/// Uses three bits to perform a lookup into a table, where the last bit
30/// performs negation
31pub trait ThreeBitCondNegLookupGadget<ConstraintF: Field>
32where
33    Self: Sized,
34{
35    type TableConstant;
36    fn three_bit_cond_neg_lookup(
37        bits: &[Boolean<ConstraintF>],
38        b0b1: &Boolean<ConstraintF>,
39        constants: &[Self::TableConstant],
40    ) -> Result<Self, SynthesisError>;
41}