1 files changed, 10 insertions, 0 deletions
diff --git a/src/Language.hs b/src/Language.hs
index 88cb1de..aa55140 100644
--- a/src/Language.hs
+++ b/src/Language.hs
@@ -2,6 +2,7 @@
 {-# LANGUAGE ExplicitForAll #-}
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE TypeApplications #-}
 module Language (
@@ -13,6 +14,7 @@ module Language (
 
 import Array
 import AST
+import CHAD.Types
 import Data
 import Language.AST
 
@@ -126,6 +128,14 @@ oper = NEOp
 error_ :: KnownTy t => String -> NExpr env t
 error_ s = NEError knownTy s
 
+custom :: (Var n1 a :-> Var n2 b :-> NExpr ['(n2, b), '(n1, a)] t)
+       -> (Var nf1 (D1 a) :-> Var nf2 (D1 b) :-> NExpr ['(nf2, D1 b), '(nf1, D1 a)] (TPair (D1 t) tape))
+       -> (Var nr1 tape :-> Var nr2 (D2 t) :-> NExpr ['(nr2, D2 t), '(nr1, tape)] (D2 b))
+       -> NExpr env a -> NExpr env b
+       -> NExpr env t
+custom (n1 :-> n2 :-> a) (nf1 :-> nf2 :-> b) (nr1 :-> nr2 :-> c) e1 e2 =
+  NECustom n1 n2 a nf1 nf2 b nr1 nr2 c e1 e2
+
 (.==) :: (KnownScalTy st, ScalIsNumeric st ~ True) => NExpr env (TScal st) -> NExpr env (TScal st) -> NExpr env (TScal TBool)
 a .== b = oper (OEq knownScalTy) (pair a b)
 infix 4 .==