From c6e07f1680fc9e8c8e96e3f2e92e25e82feddc2b Mon Sep 17 00:00:00 2001
From: Mann mit Hut <mmh@riseup.net>
Date: Wed, 10 Feb 2021 13:33:14 +0100
Subject: [PATCH 1/2] Expose a traversal over immediate subexpressions with the
 ability to map over embedded values

---
 dhall/src/Dhall/Core.hs   |  1 +
 dhall/src/Dhall/Syntax.hs | 25 +++++++++++++++++--------
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/dhall/src/Dhall/Core.hs b/dhall/src/Dhall/Core.hs
index 1d970994f..7c5f0efd8 100644
--- a/dhall/src/Dhall/Core.hs
+++ b/dhall/src/Dhall/Core.hs
@@ -56,6 +56,7 @@ module Dhall.Core (
 
     -- * Optics
     , subExpressions
+    , subExpressionsWith
     , chunkExprs
     , bindingExprs
     , recordFieldExprs
diff --git a/dhall/src/Dhall/Syntax.hs b/dhall/src/Dhall/Syntax.hs
index 9cf8087ec..252b50bb6 100644
--- a/dhall/src/Dhall/Syntax.hs
+++ b/dhall/src/Dhall/Syntax.hs
@@ -44,6 +44,7 @@ module Dhall.Syntax (
 
     -- ** Optics
     , subExpressions
+    , subExpressionsWith
     , unsafeSubExpressions
     , chunkExprs
     , bindingExprs
@@ -757,16 +758,24 @@ data MultiLet s a = MultiLet (NonEmpty (Binding s a)) (Expr s a)
 -- | A traversal over the immediate sub-expressions of an expression.
 subExpressions
     :: Applicative f => (Expr s a -> f (Expr s a)) -> Expr s a -> f (Expr s a)
-subExpressions _ (Embed a) = pure (Embed a)
-subExpressions f (Note a b) = Note a <$> f b
-subExpressions f (Let a b) = Let <$> bindingExprs f a <*> f b
-subExpressions f (Record a) = Record <$> traverse (recordFieldExprs f) a
-subExpressions f (RecordLit a) = RecordLit <$> traverse (recordFieldExprs f) a
-subExpressions f (Lam cs fb e) = Lam cs <$> functionBindingExprs f fb <*> f e
-subExpressions f (Field a b) = Field <$> f a <*> pure b
-subExpressions f expression = unsafeSubExpressions f expression
+subExpressions = subExpressionsWith (pure . Embed)
 {-# INLINABLE subExpressions #-}
 
+{-| A traversal over the immediate sub-expressions of an expression which
+    allows mapping embedded values
+-}
+subExpressionsWith
+    :: Applicative f => (a -> f (Expr s b)) -> (Expr s a -> f (Expr s b)) -> Expr s a -> f (Expr s b)
+subExpressionsWith h _ (Embed a) = h a
+subExpressionsWith _ f (Note a b) = Note a <$> f b
+subExpressionsWith _ f (Let a b) = Let <$> bindingExprs f a <*> f b
+subExpressionsWith _ f (Record a) = Record <$> traverse (recordFieldExprs f) a
+subExpressionsWith _ f (RecordLit a) = RecordLit <$> traverse (recordFieldExprs f) a
+subExpressionsWith _ f (Lam cs fb e) = Lam cs <$> functionBindingExprs f fb <*> f e
+subExpressionsWith _ f (Field a b) = Field <$> f a <*> pure b
+subExpressionsWith _ f expression = unsafeSubExpressions f expression
+{-# INLINABLE subExpressionsWith #-}
+
 {-| An internal utility used to implement transformations that require changing
     one of the type variables of the `Expr` type
 

From c7cdb1fd94bc54ee2251a85a08f81ac4fa0d3e5a Mon Sep 17 00:00:00 2001
From: Mann mit Hut <github+mmhat@with-h.at>
Date: Sat, 18 Sep 2021 10:57:53 +0200
Subject: [PATCH 2/2] Re-run CI