newtype-th 0.3.1 → 0.3.2

raw patch · 2 files changed

+28/−17 lines, 2 filesdep ~haskell-src-metadep ~newtypedep ~template-haskell

Dependency ranges changed: haskell-src-meta, newtype, template-haskell

Files

• Control/Newtype/TH.hs +22/−11
• newtype-th.cabal +6/−6

@@ -23,7 +23,7 @@ -- ----------------------------------------------------------------------------- -module Control.Newtype.TH ( mkNewTypes ) where+module Control.Newtype.TH ( mkNewType, mkNewTypes ) where  import Control.Newtype ( Newtype(pack, unpack) ) @@ -40,28 +40,35 @@ import Language.Haskell.TH import Language.Haskell.Meta.Utils (conName, conTypes) +-- | Derive a single instance of @Newtype@.+mkNewType :: Name -> Q [Dec]+mkNewType = mkNewTypes . (:[])+ -- | Derive instances of @Newtype@, specified as a list of references --   to newtypes. mkNewTypes :: [Name] -> Q [Dec]-mkNewTypes = mapM (\n -> rewriteFamilies =<< mkInstH n <$> reify n)+mkNewTypes = mapM (\n -> rewriteFamilies =<< mkInst <$> reify n)  where+  mkInst (TyConI (NewtypeD a b c  d  _)) = mkInstFor a b c d+  mkInst (TyConI (DataD    a b c [d] _)) = mkInstFor a b c d+  mkInst x+    = error $ show x+    ++ " is not a Newtype or single-field single-constructor datatype."+   --Construct the instance declaration -- "instance Newtype (<newtype> a ...) (<field type> a ...) where"-  mkInstH name (TyConI (NewtypeD context _ vs con _))+  mkInstFor context name bnds con     = InstanceD context     ( foldl1 AppT [ ConT ''Newtype-                  , bndrsToType (ConT name) vs+                  , bndrsToType (ConT name) bnds                   , head $ conTypes con                   ] )-    [ FunD 'pack   [ Clause [] -                            (NormalB $ ConE cname) [] ]-    , FunD 'unpack [ Clause [ConP cname [VarP xname]] -                            (NormalB $ VarE xname) [] ]+    [ FunD 'pack   [Clause []                  (NormalB $ ConE cn) []]+    , FunD 'unpack [Clause [ConP cn [VarP xn]] (NormalB $ VarE xn) []]     ]    where-    cname = conName con-    xname = mkName "x"-  mkInstH name _ = error $ show name ++ " is not a Newtype"+    cn = conName con+    xn = mkName "x"  -- Given a root type and a list of type variables, converts for use as -- parameters to the newtype's type in the instance head.@@ -89,7 +96,11 @@ -- refer to it, along with the cannonical reified name and the passed -- type.   justFamily :: (Name, Type, Info) -> Maybe (Name, (Name, Type))+#if __GLASGOW_HASKELL__ >= 704+  justFamily (n, t, FamilyI (FamilyD _ n' _ _) _) = Just (n, (n', t))+#else   justFamily (n, t, TyConI (FamilyD _ n' _ _)) = Just (n, (n', t))+#endif   justFamily _ = Nothing  -- Merges all of the identical applications of the family constructor.

@@ -1,5 +1,5 @@ Name:                newtype-th-Version:             0.3.1+Version:             0.3.2 Synopsis:            A template haskell deriver to create Control.Newtype instances. Description:         Provides a template haskell based mechanism for                      deriving instances of djahandarie's Control.Newtype class.@@ -20,11 +20,11 @@   Location: git://github.com/mgsloan/newtype-th  Library-  Extensions:        TemplateHaskell+  Extensions:        CPP, TemplateHaskell   Exposed-modules:   Control.Newtype.TH-  Build-depends:     base >= 3.0 && < 6, -                     haskell-src-meta, -                     newtype, +  Build-depends:     base             >= 3.0   && < 6,+                     haskell-src-meta >= 0.0.4 && < 0.6,+                     newtype          >= 0.1   && < 0.3,                      syb,-                     template-haskell+                     template-haskell >= 2.4   && < 2.8   Ghc-options:       -Wall