{-# OPTIONS_GHC -Wno-orphans #-}

module Dhall.Syntax.Instances.Bifunctor () where

import Data.Bifunctor                 (Bifunctor (..))
import Dhall.Syntax.Binding
import Dhall.Syntax.Expr
import Dhall.Syntax.FunctionBinding
import Dhall.Syntax.Instances.Functor ()
import Dhall.Syntax.Operations
import Dhall.Syntax.RecordField

import qualified Lens.Family as Lens

instance Bifunctor Binding where
    first k (Binding src0 a src1 b src2 c) =
        Binding (fmap k src0) a (fmap k src1) (fmap adapt0 b) (fmap k src2) (first k c)
      where
        adapt0 (src3, d) = (fmap k src3, first k d)

    second = fmap

instance Bifunctor RecordField where
    first k (RecordField s0 value' s1 s2) =
        RecordField (k <$> s0) (first k value') (k <$> s1) (k <$> s2)
    second = fmap

instance Bifunctor FunctionBinding where
    first k (FunctionBinding src0 label src1 src2 type_) =
        FunctionBinding (k <$> src0) label (k <$> src1) (k <$> src2) (first k type_)

    second = fmap

instance Bifunctor Expr where
    first k (Note a b   ) = Note (k a) (first k b)
    first _ (Embed a    ) = Embed a
    first k (Let a b    ) = Let (first k a) (first k b)
    first k (Record a   ) = Record $ first k <$> a
    first k (RecordLit a) = RecordLit $ first k <$> a
    first k (Lam cs a b ) = Lam cs (first k a) (first k b)
    first k (Field a b  ) = Field (first k a) (k <$> b)
    first k  expression  = Lens.over unsafeSubExpressions (first k) expression

    second = fmap