Move lens-like utilities to Dhall.Optics module (#986)

Author: Gabriella439

dhall/dhall.cabal

@@ -478,6 +478,7 @@ Library
         Dhall.Lint,
         Dhall.Main,
         Dhall.Map,
+        Dhall.Optics,
         Dhall.Set,
         Dhall.Src,
         Dhall.Parser,

dhall/src/Dhall/Core.hs

@@ -54,12 +54,6 @@ module Dhall.Core (
     -- * Optics
     , subExpressions
     , chunkExprs
-    , rewriteOf
-    , transformOf
-    , over
-    , rewriteMOf
-    , transformMOf
-    , mapMOf
 
     -- * Miscellaneous
     , internalError
@@ -70,9 +64,8 @@ module Dhall.Core (
     ) where
 
 #if MIN_VERSION_base(4,8,0)
-import Control.Applicative (WrappedMonad(..))
 #else
-import Control.Applicative (Applicative(..), WrappedMonad(..), (<$>))
+import Control.Applicative (Applicative(..), (<$>))
 #endif
 import Control.Applicative (empty)
 import Control.Exception (Exception)
@@ -84,7 +77,6 @@ import Data.Foldable
 import Data.Functor.Identity (Identity(..))
 import Data.HashSet (HashSet)
 import Data.List.NonEmpty (NonEmpty(..))
-import Data.Profunctor.Unsafe ((#.))
 import Data.String (IsString(..))
 import Data.Semigroup (Semigroup(..))
 import Data.Sequence (Seq, ViewL(..), ViewR(..))
@@ -96,7 +88,6 @@ import Dhall.Set (Set)
 import Dhall.Src (Src)
 import {-# SOURCE #-} Dhall.Pretty.Internal
 import GHC.Generics (Generic)
-import Lens.Family (ASetter, LensLike, over)
 import Numeric.Natural (Natural)
 import Prelude hiding (succ)
 
@@ -2154,49 +2145,3 @@ prettyURIComponent text
 throws :: (Exception e, MonadIO io) => Either e a -> io a
 throws (Left  e) = liftIO (Control.Exception.throwIO e)
 throws (Right r) = return r
-
-{-| Convenience utility identical to @"Control.Lens".`Control.Lens.rewriteOf`@
-    re-exported for convenience in order to minimize dependencies on @lens@
--}
-rewriteOf :: ASetter a b a b -> (b -> Maybe a) -> a -> b
-rewriteOf l f = go
-  where
-    go = transformOf l (\x -> maybe x go (f x))
-{-# INLINE rewriteOf #-}
-
-{-| Convenience utility identical to @"Control.Lens".`Control.Lens.transformOf`@
-    re-exported for convenience in order to minimize dependencies on @lens@
--}
-transformOf :: ASetter a b a b -> (b -> b) -> a -> b
-transformOf l f = go
-  where
-    go = f . over l go
-{-# INLINE transformOf #-}
-
-{-| Convenience utility identical to @"Control.Lens".`Control.Lens.rewriteMOf`@
-    re-exported for convenience in order to minimize dependencies on @lens@
--}
-rewriteMOf
-    :: Monad m
-    => LensLike (WrappedMonad m) a b a b -> (b -> m (Maybe a)) -> a -> m b
-rewriteMOf l f = go
-  where
-    go = transformMOf l (\x -> f x >>= maybe (return x) go)
-{-# INLINE rewriteMOf #-}
-
-{-| Convenience utility identical to @"Control.Lens".`Control.Lens.transformMOf`@
-    re-exported for convenience in order to minimize dependencies on @lens@
--}
-transformMOf
-    :: Monad m => LensLike (WrappedMonad m) a b a b -> (b -> m b) -> a -> m b
-transformMOf l f = go
-  where
-    go t = mapMOf l go t >>= f
-{-# INLINE transformMOf #-}
-
-{-| Convenience utility identical to @"Control.Lens".`Control.Lens.mapMOf`@
-    re-exported for convenience in order to minimize dependencies on @lens@
--}
-mapMOf :: LensLike (WrappedMonad m) s t a b -> (a -> m b) -> s -> m t
-mapMOf l cmd = unwrapMonad #. l (WrapMonad #. cmd)
-{-# INLINE mapMOf #-}

dhall/src/Dhall/Freeze.hs

@@ -34,6 +34,7 @@ import qualified Data.Text.Prettyprint.Doc.Render.Terminal as Pretty
 import qualified Data.Text.IO
 import qualified Dhall.Core
 import qualified Dhall.Import
+import qualified Dhall.Optics
 import qualified Dhall.TypeCheck
 import qualified System.FilePath
 import qualified System.IO
@@ -208,7 +209,7 @@ freeze inplace scope intent characterSet _standardVersion = do
                 Secure ->
                     traverse freezeFunction expression
                 Cache  ->
-                    Dhall.Core.transformMOf
+                    Dhall.Optics.transformMOf
                         Dhall.Core.subExpressions
                         cache
                         (Dhall.Core.denote expression)

dhall/src/Dhall/Lint.hs

@@ -14,6 +14,7 @@ import Data.Semigroup ((<>))
 import Dhall.Core (Binding(..), Expr(..), Import, Var(..), subExpressions)
 
 import qualified Dhall.Core
+import qualified Dhall.Optics
 
 {-| Automatically improve a Dhall expression
 
@@ -25,7 +26,7 @@ import qualified Dhall.Core
 -}
 lint :: Expr s Import -> Expr t Import
 lint =
-  Dhall.Core.rewriteOf
+  Dhall.Optics.rewriteOf
     subExpressions
     ( \e ->
                 removeLetInLet e

dhall/src/Dhall/Optics.hs

@@ -0,0 +1,53 @@
+{-| This module contains some useful utilities copy-and-pasted from the @lens@
+    library to avoid a dependency which are used internally and also re-exported
+    for convenience
+-}
+
+module Dhall.Optics
+    ( -- * Utilities
+      rewriteOf
+    , transformOf
+    , rewriteMOf
+    , transformMOf
+    , mapMOf
+    ) where
+
+import Control.Applicative (WrappedMonad(..))
+import Data.Profunctor.Unsafe ((#.))
+import Lens.Family (ASetter, LensLike, over)
+
+-- | Identical to @"Control.Lens".`Control.Lens.rewriteOf`@
+rewriteOf :: ASetter a b a b -> (b -> Maybe a) -> a -> b
+rewriteOf l f = go
+  where
+    go = transformOf l (\x -> maybe x go (f x))
+{-# INLINE rewriteOf #-}
+
+-- | Identical to @"Control.Lens".`Control.Lens.transformOf`@
+transformOf :: ASetter a b a b -> (b -> b) -> a -> b
+transformOf l f = go
+  where
+    go = f . over l go
+{-# INLINE transformOf #-}
+
+-- | Identical to @"Control.Lens".`Control.Lens.rewriteMOf`@
+rewriteMOf
+    :: Monad m
+    => LensLike (WrappedMonad m) a b a b -> (b -> m (Maybe a)) -> a -> m b
+rewriteMOf l f = go
+  where
+    go = transformMOf l (\x -> f x >>= maybe (return x) go)
+{-# INLINE rewriteMOf #-}
+
+-- | Identical to @"Control.Lens".`Control.Lens.transformMOf`@
+transformMOf
+    :: Monad m => LensLike (WrappedMonad m) a b a b -> (b -> m b) -> a -> m b
+transformMOf l f = go
+  where
+    go t = mapMOf l go t >>= f
+{-# INLINE transformMOf #-}
+
+-- | Identical to @"Control.Lens".`Control.Lens.mapMOf`@
+mapMOf :: LensLike (WrappedMonad m) s t a b -> (a -> m b) -> s -> m t
+mapMOf l cmd = unwrapMonad #. l (WrapMonad #. cmd)
+{-# INLINE mapMOf #-}