reflection 1.3.2 → 1.4

raw patch · 3 files changed

+68/−19 lines, 3 files

Files

• CHANGELOG.markdown +4/−0
• fast/Data/Reflection.hs +59/−18
• reflection.cabal +5/−1

@@ -1,3 +1,7 @@++# 1.4+* Changed the behavior of the $(1) template haskell splices for Exp to use a Proxy rather than value-level numbers. This is more consistent with the role of this libraary and the other could always be generated via sa splice anyways.+ # 1.3.1 * Added a workaround for changes in the behavior of the internal 'Magic' datatype under the current GHC PolyKinds implementation. 

@@ -1,3 +1,4 @@+{-# LANGUAGE PatternGuards #-} {-# LANGUAGE CPP #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FunctionalDependencies #-}@@ -155,6 +156,11 @@ -- -- This does not use GHC TypeLits, instead it generates a numeric type by hand similar to the ones used -- in the \"Functional Pearl: Implicit Configurations\" paper by Oleg Kiselyov and Chung-Chieh Shan.+--+-- @instance Num (Q Exp)@ provided in this package allows writing @$(3)@+-- instead of @$(int 3)@. Sometimes the two will produce the same+-- representation (if compiled without the @-DUSE_TYPE_LITS@ preprocessor+-- directive). int :: Int -> TypeQ int n = case quotRem n 2 of   (0, 0) -> conT ''Z@@ -192,7 +198,10 @@ -- | This permits the use of $(5) as a type splice. instance Num Type where #ifdef USE_TYPE_LITS+  LitT (NumTyLit a) + LitT (NumTyLit b) = LitT (NumTyLit (a+b))   a + b = AppT (AppT (VarT ''(+)) a) b++  LitT (NumTyLit a) * LitT (NumTyLit b) = LitT (NumTyLit (a*b))   a * b = AppT (AppT (VarT ''(*)) a) b #if MIN_VERSION_base(4,8,0)   a - b = AppT (AppT (VarT ''(-)) a) b@@ -214,24 +223,56 @@   abs = error "Type.abs"   signum = error "Type.signum" -plus, times, minus :: Num a => a -> a -> a-plus = (+)-times = (*)-minus = (-)-fract :: Fractional a => a -> a -> a-fract = (/) --- | This permits the use of $(5) as an expression splice.+onProxyType1 :: (Type -> Type) -> (Exp -> Exp)+onProxyType1 f+    (SigE _ ta@(AppT (ConT proxyName)  (VarT _)))+    | proxyName == ''Proxy = ConE 'Proxy `SigE` (ConT ''Proxy `AppT` f ta)+onProxyType1 f a =+        LamE [SigP WildP na] body `AppE` a+    where +          body = ConE 'Proxy `SigE` (ConT ''Proxy `AppT` f na)+          na = VarT (mkName "na")++onProxyType2 :: Name -> (Type -> Type -> Type) -> (Exp -> Exp -> Exp)+onProxyType2 _fName f+    (SigE _ (AppT (ConT proxyName)  ta))+    (SigE _ (AppT (ConT proxyName') tb))+    | proxyName == ''Proxy,+      proxyName' == ''Proxy = ConE 'Proxy `SigE`+                                        (ConT ''Proxy `AppT` f ta tb)+-- the above case should only match for things like $(2 + 2)+onProxyType2 fName _f a b = VarE fName `AppE` a `AppE` b++-- | This permits the use of $(5) as an expression splice,+-- which stands for @Proxy :: Proxy $(5)@ instance Num Exp where-  a + b = AppE (AppE (VarE 'plus) a) b-  a * b = AppE (AppE (VarE 'times) a) b-  a - b = AppE (AppE (VarE 'minus) a) b-  negate = AppE (VarE 'negate)-  signum = AppE (VarE 'signum)-  abs = AppE (VarE 'abs)-  fromInteger = LitE . IntegerL+  (+) = onProxyType2 'addProxy (+)+  (*) = onProxyType2 'mulProxy (*)+  (-) = onProxyType2 'subProxy (-)+  negate = onProxyType1 negate+  abs = onProxyType1 abs+  signum = onProxyType1 signum+  fromInteger n = ConE 'Proxy `SigE` (ConT ''Proxy `AppT` fromInteger n) -instance Fractional Exp where-  a / b = AppE (AppE (VarE 'fract) a) b-  recip = AppE (VarE 'recip)-  fromRational = LitE . RationalL+#ifdef USE_TYPE_LITS+addProxy :: Proxy a -> Proxy b -> Proxy (a + b)+addProxy _ _ = Proxy+mulProxy :: Proxy a -> Proxy b -> Proxy (a * b)+mulProxy _ _ = Proxy+#if MIN_VERSION_base(4,8,0)+subProxy :: Proxy a -> Proxy b -> Proxy (a - b)+subProxy _ _ = Proxy+#else+subProxy :: Proxy a -> Proxy b -> Proxy c+subProxy _ _ = error "Exp.(-): undefined"+#endif+--  fromInteger = LitT . NumTyLit+#else+addProxy :: Proxy a -> Proxy b -> Proxy c+addProxy _ _ = error "Exp.(+): undefined"+mulProxy :: Proxy a -> Proxy b -> Proxy c+mulProxy _ _ = error "Exp.(*): undefined"+subProxy :: Proxy a -> Proxy b -> Proxy c+subProxy _ _ = error "Exp.(-): undefined"+#endif

@@ -1,5 +1,5 @@ name:           reflection-version:        1.3.2+version:        1.4 license:        BSD3 license-file:   LICENSE author:         Edward A. Kmett, Elliott Hird, Oleg Kiselyov and Chung-chieh Shan@@ -21,6 +21,10 @@   .   The original paper can be obtained from   <http://www.cs.rutgers.edu/~ccshan/prepose/prepose.pdf>.+  .+  For a summary of the approach taken by this library, along with more motivating+  examples, see Austin Seipp's tutorial at+  <https://www.fpcomplete.com/user/thoughtpolice/using-reflection>.  extra-source-files:   examples/Monoid.hs