2 files changed, 22 insertions, 14 deletions
diff --git a/dhall_syntax/src/core/expr.rs b/dhall_syntax/src/core/expr.rs
index eeee4d8..f46cafb 100644
--- a/dhall_syntax/src/core/expr.rs
+++ b/dhall_syntax/src/core/expr.rs
@@ -313,21 +313,25 @@ impl<SE, E> ExprF<SE, E> {
 }
 
 impl<E> RawExpr<E> {
-    pub fn traverse_resolve<E2, Err>(
+    pub fn traverse_resolve<Err>(
         &self,
-        visit_import: impl FnMut(&Import<Expr<E2>>) -> Result<E2, Err>,
-    ) -> Result<RawExpr<E2>, Err> {
+        visit_import: impl FnMut(&Import<Expr<E>>) -> Result<E, Err>,
+    ) -> Result<RawExpr<E>, Err>
+    where
+        E: Clone,
+    {
         self.traverse_resolve_with_visitor(&mut visitor::ResolveVisitor(
             visit_import,
         ))
     }
 
-    pub(crate) fn traverse_resolve_with_visitor<E2, Err, F1>(
+    pub(crate) fn traverse_resolve_with_visitor<Err, F1>(
         &self,
         visitor: &mut visitor::ResolveVisitor<F1>,
-    ) -> Result<RawExpr<E2>, Err>
+    ) -> Result<RawExpr<E>, Err>
     where
-        F1: FnMut(&Import<Expr<E2>>) -> Result<E2, Err>,
+        E: Clone,
+        F1: FnMut(&Import<Expr<E>>) -> Result<E, Err>,
     {
         match self {
             ExprF::BinOp(BinOp::ImportAlt, l, r) => l
@@ -368,10 +372,13 @@ impl<E> Expr<E> {
 }
 
 impl<E> Expr<E> {
-    pub fn traverse_resolve<E2, Err>(
+    pub fn traverse_resolve<Err>(
         &self,
-        visit_import: impl FnMut(&Import<Expr<E2>>) -> Result<E2, Err>,
-    ) -> Result<Expr<E2>, Err> {
+        visit_import: impl FnMut(&Import<Expr<E>>) -> Result<E, Err>,
+    ) -> Result<Expr<E>, Err>
+    where
+        E: Clone,
+    {
         Ok(self.rewrap(self.as_ref().traverse_resolve(visit_import)?))
     }
 }
diff --git a/dhall_syntax/src/core/visitor.rs b/dhall_syntax/src/core/visitor.rs
index 435771e..addb282 100644
--- a/dhall_syntax/src/core/visitor.rs
+++ b/dhall_syntax/src/core/visitor.rs
@@ -250,24 +250,25 @@ where
 
 pub struct ResolveVisitor<F1>(pub F1);
 
-impl<'a, 'b, E, E2, Err, F1> ExprFFallibleVisitor<'a, Expr<E>, Expr<E2>, E, E2>
+impl<'a, 'b, E, Err, F1> ExprFFallibleVisitor<'a, Expr<E>, Expr<E>, E, E>
     for &'b mut ResolveVisitor<F1>
 where
-    F1: FnMut(&Import<Expr<E2>>) -> Result<E2, Err>,
+    E: Clone,
+    F1: FnMut(&Import<Expr<E>>) -> Result<E, Err>,
 {
     type Error = Err;
 
     fn visit_subexpr(
         &mut self,
         subexpr: &'a Expr<E>,
-    ) -> Result<Expr<E2>, Self::Error> {
+    ) -> Result<Expr<E>, Self::Error> {
         Ok(subexpr.rewrap(
             subexpr
                 .as_ref()
                 .traverse_resolve_with_visitor(&mut **self)?,
         ))
     }
-    fn visit_embed(self, _embed: &'a E) -> Result<E2, Self::Error> {
-        unimplemented!()
+    fn visit_embed(self, embed: &'a E) -> Result<E, Self::Error> {
+        Ok(embed.clone())
     }
 }