traverse-with-class 1.0.0.0 → 1.0.1.0

raw patch · 3 files changed

+116/−1 lines, 3 filesPVP: major bump suggested

API removals or changes: PVP suggests a major version bump

API changes (from Hackage documentation)

Files

• CHANGES.md +5/−0
• Data/Generics/Traversable/Generic.hs +109/−0
• traverse-with-class.cabal +2/−1

@@ -1,6 +1,11 @@ Changes ======= +Version 1.0.1.0+---------------++Add `Data.Generics.Traversable.Generic`+ Version 1.0.0.0 --------------- 

@@ -0,0 +1,109 @@+-- | For a datatype where /every/ subterm is interesting, it is+-- possible to leverage 'Generic' to automatically produce the+-- 'GTraversable' instance.+--+-- This module defines a default 'GTraversable' instance for most+-- 'Generic' types, though you can override it with a custom instance+-- if you so wish. The 'gtraverse' implementation for this instance+-- traverses every subterm, and traverses left-to-right on products+-- ':*:'.+--+-- Example usage:+--+-- >{-# LANGUAGE FlexibleInstances, DeriveGeneric #-}+-- >import Data.Maybe (isJust)+-- >+-- >data MyConfig = MyConfig+-- >  { firstKey  :: Maybe Int+-- >  , secondKey :: Maybe String+-- >  , thirdKey  :: Maybe Bool+-- >  }+-- >  deriving (Generic)+-- >+-- >class SettableConfigKey a where+-- >  isSet :: a -> Bool+-- >+-- >instance SettableConfigKey (Maybe a) where+-- >  isSet = isJust+-- >+-- >isAnyConfigKeySet :: MyConfig -> Bool+-- >isAnyConfigKeySet = gfoldr @SettableConfigKey ((||) . isSet)+--+-- For 'Generic' types that have 'Rec1' in their representation, this+-- module will not work for GHC versions below 8.6.1, as the instance+-- makes use of @QuantifiedConstraints@. Instead, the instance for+-- 'Rec1' will cause a type error.+{-# LANGUAGE CPP #-}+{-# LANGUAGE TypeOperators #-}+{-# LANGUAGE ScopedTypeVariables #-}++# if MIN_VERSION_GLASGOW_HASKELL(8, 6, 1, 0)+{-# LANGUAGE QuantifiedConstraints #-}+# else+{-# LANGUAGE DataKinds #-}+# endif++{-# OPTIONS_GHC -Wno-orphans #-}+module Data.Generics.Traversable.Generic where++import Data.Generics.Traversable+import GHC.Generics++# if MIN_VERSION_GLASGOW_HASKELL(8, 6, 1, 0)+# else+import GHC.TypeLits (TypeError, ErrorMessage (..))+# endif++-- | Special version of 'GTraversable' for the representation types+-- from 'Generic'.+class GTraversable' c (f :: * -> *) where+  gtraverse' :: Applicative g => (forall d. c d => d -> g d) -> (forall p. f p -> g (f p))++instance GTraversable' c U1 where+  gtraverse' _f U1 = pure U1++instance GTraversable' c V1 where+  gtraverse' _f = error "Impossible"++instance GTraversable' c Par1 where+  gtraverse' _f par1 = pure par1++# if MIN_VERSION_GLASGOW_HASKELL(8, 6, 1, 0)+instance (forall p. GTraversable c (f p)) => GTraversable' c (Rec1 f) where+  gtraverse' f (Rec1 recur) = Rec1 <$> gtraverse @c f recur+# else+instance+    ( TypeError+      ( 'Text "No generic instance can be derived for " ':$$: 'ShowType f ':$$:+        'Text " for this GHC version - upgrade to at least 8.6.1 to be" ':$$:+        'Text " able to use `GTraversable` from `Generic` here"+      )+    )+  => GTraversable' c (Rec1 f) where+  gtraverse' _ _ = error "Cannot implement `gtraverse'` for this type"+# endif++instance (c con) => GTraversable' c (K1 i con) where+  gtraverse' f (K1 con) = K1 <$> f con++instance (GTraversable' c f) => GTraversable' c (M1 i meta f) where+  gtraverse' f (M1 inner) = M1 <$> gtraverse' @c f inner++instance (GTraversable' c f, GTraversable' c g) => GTraversable' c (f :+: g) where+  gtraverse' f (L1 val) = L1 <$> gtraverse' @c f val+  gtraverse' f (R1 val) = R1 <$> gtraverse' @c f val++instance (GTraversable' c f, GTraversable' c g) => GTraversable' c (f :*: g) where+  gtraverse' f (left :*: right)+    = (:*:) <$> gtraverse' @c f left <*> gtraverse' @c f right++instance (Traversable f, GTraversable' c g) => GTraversable' c (f :.: g) where+  gtraverse' f (Comp1 comp) = Comp1 <$> traverse (gtraverse' @c f) comp++instance+    {-# OVERLAPPABLE #-}+    (Generic a, GTraversable' c (Rep a))+  => GTraversable c a+  where+  gtraverse f val+    = to <$> gtraverse' @c f (from val)

@@ -2,7 +2,7 @@ -- documentation, see http://haskell.org/cabal/users-guide/  name:                traverse-with-class-version:             1.0.0.0+version:             1.0.1.0 synopsis:            Generic applicative traversals description:         This is a generic programming library in the spirit of                      \"Scrap your boilerplate with class\", but with several@@ -28,6 +28,7 @@  library   exposed-modules:     Data.Generics.Traversable+                       Data.Generics.Traversable.Generic                        Data.Generics.Traversable.TH                        Data.Generics.Traversable.Zipper   other-modules: