vector-th-unbox 0.2.0.1 → 0.2.0.2
raw patch · 3 files changed
+96/−32 lines, 3 filesdep +data-defaultdep +vector-th-unboxdep ~basedep ~vector
Dependencies added: data-default, vector-th-unbox
Dependency ranges changed: base, vector
Files
- Data/Vector/Unboxed/Deriving.hs +51/−28
- tests/sanity.hs +27/−0
- vector-th-unbox.cabal +18/−4
Data/Vector/Unboxed/Deriving.hs view
@@ -1,5 +1,6 @@ {-# LANGUAGE CPP #-} {-# LANGUAGE MultiParamTypeClasses #-}+{-# LANGUAGE RecordWildCards #-} {-# LANGUAGE TemplateHaskell #-} #if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702 {-# LANGUAGE Trustworthy #-}@@ -10,7 +11,7 @@ {-| Module: Data.Vector.Unboxed.Deriving-Copyright: © Liyang HU 2012+Copyright: © 2012−2013 Liyang HU License: BSD3 Maintainer: vector-th-unbox@liyang.hu Stability: experimental@@ -18,11 +19,10 @@ Writing @Unbox@ instances for new data types is tedious and formulaic. More often than not, there is a straightforward mapping of the new type onto some-existing one already imbued with an @Unbox@ instance. The example from the-@vector@ package represents @Complex a@ as pairs @(a, a)@. (See-<http://hackage.haskell.org/packages/archive/vector/latest/doc/html/Data-Vector-Unboxed.html>.)-Using 'derivingUnbox', we can define the same instances much more-succinctly:+existing one already imbued with an @Unbox@ instance. The+<http://hackage.haskell.org/package/vector/docs/Data-Vector-Unboxed.html example>+from the @vector@ package represents @Complex a@ as pairs @(a, a)@. Using+'derivingUnbox', we can define the same instances much more succinctly: >derivingUnbox "Complex" > [t| (Unbox a) ⇒ Complex a → (a, a) |]@@ -30,12 +30,17 @@ > [| \ (r, i) → r :+ i |] Requires the @MultiParamTypeClasses@, @TemplateHaskell@, @TypeFamilies@ and-probably the @FlexibleInstances@ @LANGUAGE@ extensions. Older versions of-GHC needs the 'G.Vector' and 'M.MVector' class method names in scope:+probably the @FlexibleInstances@ @LANGUAGE@ extensions. Note that GHC 7.4+(but not earlier nor later) needs the 'G.Vector' and 'M.MVector' class+method names to be in scope in order to define the appropriate instances: +>#if __GLASGOW_HASKELL == 704 >import qualified Data.Vector.Generic >import qualified Data.Vector.Generic.Mutable+>#endif +Consult the <https://github.com/liyang/vector-th-unbox/blob/master/tests/sanity.hs sanity test>+for a working example. -} module Data.Vector.Unboxed.Deriving (derivingUnbox) where@@ -48,30 +53,55 @@ import Data.Vector.Unboxed.Base (MVector (..), Vector (..), Unbox) import Language.Haskell.TH +consUnbox :: String -> (Name, Name)+consUnbox name = (mkName $ "MV_" ++ name, mkName $ "V_" ++ name)+ -- Create a @Pat@ bound to the given name and an @Exp@ for said binding. newPatExp :: String -> Q (Pat, Exp) newPatExp = fmap (VarP &&& VarE) . newName +data Common = Common+ { mvName, vName :: Name+ , i, n, mv, mv', v :: (Pat, Exp) }++common :: String -> Q Common+common name = do+ let (mvName, vName) = consUnbox name+ i <- newPatExp "idx"+ n <- newPatExp "len"+ mv <- first (ConP mvName . (:[])) <$> newPatExp "mvec"+ mv' <- first (ConP mvName . (:[])) <$> newPatExp "mvec'"+ v <- first (ConP vName . (:[])) <$> newPatExp "vec"+ return Common {..}++-- Turn any 'Name' into a capturable one.+capture :: Name -> Name+capture = mkName . nameBase++liftE :: Exp -> Exp -> Exp+liftE e = InfixE (Just e) (VarE 'liftM) . Just+ -- Create a wrapper for the given function with the same 'nameBase', given -- a list of argument bindings and expressions in terms of said bindings. -- A final coercion (@Exp → Exp@) is applied to the body of the function. -- Complimentary @INLINE@ pragma included. wrap :: Name -> [(Pat, Exp)] -> (Exp -> Exp) -> [Dec] wrap fun (unzip -> (pats, exps)) coerce = [inline, method] where+ name = capture fun #if MIN_VERSION_template_haskell(2,8,0)- inline = PragmaD (InlineP fun Inline FunLike AllPhases)+ inline = PragmaD (InlineP name Inline FunLike AllPhases) #else- inline = PragmaD ( InlineP (mkName (nameBase fun))- (InlineSpec True False Nothing) )+ inline = PragmaD ( InlineP name (InlineSpec True False Nothing) ) #endif body = coerce $ foldl AppE (VarE fun) exps- method = FunD fun [Clause pats (NormalB body) []]+ method = FunD name [Clause pats (NormalB body) []] {-| Let's consider a more complex example: suppose we want an @Unbox@-instance for @Maybe a@. We can encode this using the pair @(Bool, a)@, with-the boolean indicating whether we have @Nothing@ or @Just@ something. This-encoding requires a dummy value in the @Nothing@ case, necessitating an-additional @Default@ (see the @data-default@ package) constraint. Thus:+instance for @Maybe a@. We could encode this using the pair @(Bool, a)@,+with the boolean indicating whether we have @Nothing@ or @Just@ something.+This encoding requires a dummy value in the @Nothing@ case, necessitating an+additional <http://hackage.haskell.org/package/data-default/docs/Data-Default.html#t:Default Default>+constraint. Thus: >derivingUnbox "Maybe" > [t| (Default a, Unbox a) ⇒ Maybe a → (Bool, a) |]@@ -85,29 +115,20 @@ -> ExpQ -- ^ Quotation of an expression of type @rep → src@ -> DecsQ -- ^ Declarations to be spliced for the derived Unbox instance derivingUnbox name argsQ toRepQ fromRepQ = do- let mvName = mkName ("MV_" ++ name)- let vName = mkName ("V_" ++ name)+ Common {..} <- common name toRep <- toRepQ fromRep <- fromRepQ+ a <- second (AppE toRep) <$> newPatExp "val" args <- argsQ (cxts, typ, rep) <- case args of ForallT _ cxts (ArrowT `AppT` typ `AppT` rep) -> return (cxts, typ, rep) ArrowT `AppT` typ `AppT` rep -> return ([], typ, rep) _ -> fail "Expecting a type of the form: cxts => typ -> rep" - let liftE e = InfixE (Just e) (VarE 'liftM) . Just- let mvCon = ConE mvName- let vCon = ConE vName- i <- newPatExp "idx"- n <- newPatExp "len"- a <- second (AppE toRep) <$> newPatExp "val"- mv <- first (ConP mvName . (:[])) <$> newPatExp "mvec"- mv' <- first (ConP mvName . (:[])) <$> newPatExp "mvec'"- v <- first (ConP vName . (:[])) <$> newPatExp "vec"- s <- VarT <$> newName "s" let newtypeMVector = NewtypeInstD [] ''MVector [s, typ] (NormalC mvName [(NotStrict, ConT ''MVector `AppT` s `AppT` rep)]) []+ let mvCon = ConE mvName let instanceMVector = InstanceD cxts (ConT ''M.MVector `AppT` ConT ''MVector `AppT` typ) $ concat [ wrap 'M.basicLength [mv] id@@ -120,10 +141,12 @@ , wrap 'M.basicClear [mv] id , wrap 'M.basicSet [mv, a] id , wrap 'M.basicUnsafeCopy [mv, mv'] id+ , wrap 'M.basicUnsafeMove [mv, mv'] id , wrap 'M.basicUnsafeGrow [mv, n] (liftE mvCon) ] let newtypeVector = NewtypeInstD [] ''Vector [typ] (NormalC vName [(NotStrict, ConT ''Vector `AppT` rep)]) []+ let vCon = ConE vName let instanceVector = InstanceD cxts (ConT ''G.Vector `AppT` ConT ''Vector `AppT` typ) $ concat [ wrap 'G.basicUnsafeFreeze [mv] (liftE vCon)
+ tests/sanity.hs view
@@ -0,0 +1,27 @@+{-# LANGUAGE CPP #-}+{-# LANGUAGE MultiParamTypeClasses #-}+{-# LANGUAGE TemplateHaskell #-}+{-# LANGUAGE TypeFamilies #-}+{-# LANGUAGE UnicodeSyntax #-}+{-# OPTIONS_GHC -fno-warn-orphans #-}+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 706+{-# OPTIONS_GHC -fno-warn-unused-imports #-}+#endif++module Main (main) where++import Prelude+import Data.Default+import qualified Data.Vector.Generic+import qualified Data.Vector.Generic.Mutable+import Data.Vector.Unboxed.Base (Unbox)+import Data.Vector.Unboxed.Deriving++derivingUnbox "Maybe"+ [t| (Default a, Unbox a) ⇒ Maybe a → (Bool, a) |]+ [| maybe (False, def) (\ x → (True, x)) |]+ [| \ (b, x) → if b then Just x else Nothing |]++main ∷ IO ()+main = return ()+
vector-th-unbox.cabal view
@@ -1,5 +1,5 @@ name: vector-th-unbox-version: 0.2.0.1+version: 0.2.0.2 synopsis: Deriver for Data.Vector.Unboxed using Template Haskell description: A Template Haskell deriver for unboxed vectors, given a pair of coercion@@ -9,17 +9,19 @@ stability: experimental license: BSD3 license-file: LICENSE-author: Liyang HU-maintainer: vector-th-unbox@liyang.hu+copyright: © 2012−2013 Liyang HU+author: Liyang HU <vector-th-unbox@liyang.hu>+maintainer: Liyang HU <vector-th-unbox@liyang.hu> category: Data build-type: Simple-cabal-version: >= 1.6+cabal-version: >= 1.10 source-repository head type: git location: http://github.com/liyang/vector-th-unbox library+ default-language: Haskell2010 exposed-modules: Data.Vector.Unboxed.Deriving @@ -27,6 +29,18 @@ base >= 4.3 && < 5, template-haskell >= 2.5, vector >= 0.7++test-suite sanity+ default-language: Haskell2010+ type: exitcode-stdio-1.0+ hs-source-dirs: tests+ main-is: sanity.hs+ build-depends:+ base,+ data-default,+ vector,+ vector-th-unbox+ ghc-options: -Wall -- vim: et sw=4 ts=4 sts=4: