module ZkFold.Symbolic.Data.Eq.Structural where

import           Data.Function             (id)
import           Data.List                 (null, zipWith)

import           ZkFold.Symbolic.Compiler
import           ZkFold.Symbolic.Data.Bool
import           ZkFold.Symbolic.Data.Eq

newtype Structural a = Structural a
-- ^ A newtype wrapper for easy definition of Eq instances.

instance SymbolicData a x => Eq (Bool (ArithmeticCircuit a)) (Structural x) where
    Structural x == Structural y =
        let x' = pieces @a x
            y' = pieces y
            zs = zipWith (==) x' y'
         in if null zs
              then true
              else all1 id zs

    Structural x /= Structural y =
        let x' = pieces @a x
            y' = pieces y
            zs = zipWith (==) x' y'
         in if null zs
              then false
              else not (all1 id zs)