generic-constraints 1.0.0 → 1.1.0

raw patch · 4 files changed

+49/−7 lines, 4 filesdep +template-haskelldep +th-abstractionPVP ok

version bump matches the API change (PVP)

Dependencies added: template-haskell, th-abstraction

API changes (from Hackage documentation)

Files

• CHANGELOG +3/−0
• generic-constraints.cabal +3/−1
• src/Generics/Constraints.hs +38/−3
• test/unittests.hs +5/−3

@@ -1,4 +1,7 @@ CHANGELOG +1.1+  - Added TH to generate standalone deriving clauses+ 1.0   - Extracted generic-constraints from Sjoerd Visscher's & Xia Li-yao's one-liner library, as advised by Sjoerd

@@ -1,5 +1,5 @@ Name:                 generic-constraints-Version:              1.0.0+Version:              1.1.0 Synopsis:             Constraints via Generic Description:          Write short and concise contexts based on generics Homepage:             https://github.com/yairchu/generic-constraints@@ -23,6 +23,8 @@    Build-depends:       base          >= 4.9 && < 5+    , template-haskell+    , th-abstraction    ghc-options:     -Wall

@@ -3,11 +3,18 @@   , TypeFamilies   , TypeOperators   , ConstraintKinds+  , TemplateHaskellQuotes   #-}-module Generics.Constraints (Constraints) where+module Generics.Constraints+    ( Constraints+    , makeDeriving, makeDerivings+    , makeInstance, makeInstances+    ) where -import Data.Kind (Constraint, Type)-import GHC.Generics+import           Data.Kind (Constraint, Type)+import           GHC.Generics+import qualified Language.Haskell.TH as T+import qualified Language.Haskell.TH.Datatype as D  type family Constraints' (t :: Type -> Type) (c :: Type -> Constraint) :: Constraint type instance Constraints' V1 c = ()@@ -24,3 +31,31 @@ -- requirements for an instance for `t` of class `c`. -- It requires an instance of class `c` for each component of `t`. type Constraints t c = Constraints' (Rep t) c++makeDerivings :: [T.Name] -> [T.Name] -> T.DecsQ+makeDerivings = makeMany makeDeriving++makeInstances :: [T.Name] -> [T.Name] -> T.DecsQ+makeInstances = makeMany makeDeriving++makeMany :: (T.Name -> T.Name -> T.DecsQ) -> [T.Name] -> [T.Name] -> T.DecsQ+makeMany f classes types = concat <$> sequence (f <$> classes <*> types)++makeDeriving :: T.Name -> T.Name -> T.DecsQ+makeDeriving = makeCommon (T.StandaloneDerivD Nothing)++makeInstance :: T.Name -> T.Name -> T.DecsQ+makeInstance = makeCommon (\c i -> T.InstanceD Nothing c i [])++makeCommon :: ([T.Type] -> T.Type -> T.Dec) -> T.Name -> T.Name -> T.DecsQ+makeCommon f clsName typName =+    r <$> D.reifyDatatype typName+    where+        r info =+            [ f [T.ConT ''Constraints `T.AppT` typ `T.AppT` T.ConT clsName]+                (T.ConT clsName `T.AppT` typ)+            ]+            where+                typ =+                    foldl T.AppT (T.ConT typName)+                    (T.VarT . D.tvName <$> D.datatypeVars info)

@@ -1,5 +1,6 @@ {-# LANGUAGE     DeriveGeneric+  , TemplateHaskell   , StandaloneDeriving   , UndecidableInstances #-}@@ -11,10 +12,11 @@ data T a = T (a Int)     deriving Generic -deriving instance Constraints (T a) Eq   => Eq   (T a)-deriving instance Constraints (T a) Ord  => Ord  (T a)-deriving instance Constraints (T a) Show => Show (T a)+makeDeriving ''Eq   ''T+makeDeriving ''Ord  ''T+makeDeriving ''Show ''T +main :: IO Counts main = runTestTT $ test   [ assert (T [5] > T [3])   ]