Replace SystemT with an ReaderT alias, drop deps

apecs-physics/src/Apecs/Physics/Body.hs

@@ -18,7 +18,7 @@ module Apecs.Physics.Body where
 import           Apecs
 import           Apecs.Core
 import           Control.Monad
-import           Control.Monad.IO.Class (liftIO, MonadIO)
+import           Control.Monad.IO.Class (MonadIO)
 import qualified Data.IntMap         as M
 import qualified Data.IntSet         as S
 import           Data.IORef

apecs-physics/src/Apecs/Physics/Collision.hs

@@ -22,7 +22,7 @@ module Apecs.Physics.Collision
 import           Apecs
 import           Apecs.Core
 import           Control.Monad
-import           Control.Monad.IO.Class (MonadIO, liftIO)
+import           Control.Monad.IO.Class (MonadIO)
 import qualified Data.IntMap         as M
 import           Data.IORef
 import qualified Data.Vector.Unboxed as U

apecs-physics/src/Apecs/Physics/Constraint.hs

@@ -20,7 +20,7 @@ module Apecs.Physics.Constraint
 import           Apecs
 import           Apecs.Core
 import           Control.Monad
-import           Control.Monad.IO.Class (liftIO, MonadIO)
+import           Control.Monad.IO.Class (MonadIO)
 import qualified Data.IntMap         as M
 import qualified Data.IntSet         as S
 import           Data.IORef

apecs-physics/src/Apecs/Physics/Query.hs

@@ -16,7 +16,7 @@
 module Apecs.Physics.Query where
 
 import           Apecs
-import           Control.Monad.IO.Class (liftIO, MonadIO)
+import           Control.Monad.IO.Class (MonadIO)
 import           Foreign.C.Types
 import           Foreign.ForeignPtr    (withForeignPtr)
 import           Foreign.Marshal.Alloc

apecs-physics/src/Apecs/Physics/Space.hs

@@ -16,7 +16,7 @@ module Apecs.Physics.Space where
 
 import           Apecs
 import           Apecs.Core
-import           Control.Monad.IO.Class (liftIO, MonadIO)
+import           Control.Monad.IO.Class (MonadIO)
 import           Data.IORef
 import           Foreign.Concurrent
 import           Foreign.ForeignPtr  (withForeignPtr)

apecs/apecs.cabal

@@ -42,10 +42,8 @@ library
       array             >=0.4    && <0.6
     , base              >=4.9    && <5
     , containers        >=0.5    && <0.8
-    , exceptions        >=0.10.0 && <0.11
-    , mtl               >=2.2    && <2.4
+    , transformers      >= 0.5   && <0.7
     , template-haskell  >=2.12   && <3
-    , unliftio-core     >=0.2.0.1 && <0.3
     , vector            >=0.11   && <0.14
 
   ghc-options:      -Wall

apecs/src/Apecs.hs

@@ -4,7 +4,7 @@ It selectively re-exports the user-facing functions from the submodules.
 -}
 module Apecs (
   -- * Core types
-    SystemT(..), System, Component(..), Entity(..), Has(..), Not(..),
+    SystemT, System, Component(..), Entity(..), Has(..), Not(..),
     Get, Set, Destroy, Members,
 
   -- * Stores
@@ -30,7 +30,8 @@ module Apecs (
 ) where
 
 import           Control.Monad.IO.Class (liftIO)
-import           Control.Monad.Reader (ask, asks, lift)
+import           Control.Monad.Trans.Class (lift)
+import           Control.Monad.Trans.Reader (ask, asks)
 import           Data.Proxy
 
 import           Apecs.Components

apecs/src/Apecs/Core.hs

@@ -12,10 +12,7 @@
 
 module Apecs.Core where
 
-import           Control.Monad.Catch
-import           Control.Monad.IO.Class
-import           Control.Monad.IO.Unlift
-import           Control.Monad.Reader
+import           Control.Monad.Trans.Reader
 import qualified Data.Vector.Unboxed  as U
 
 -- | An Entity is just an integer, used to index into a component store.
@@ -30,11 +27,9 @@ newtype Entity = Entity {unEntity :: Int} deriving (Num, Eq, Ord, Show, Enum)
 --   * Allow type-based lookup of a component's store through @getStore@.
 --
 --   * Lift side effects into their host Monad.
-newtype SystemT w m a = SystemT {unSystem :: ReaderT w m a} deriving (Functor, Monad, Applicative, MonadTrans, MonadIO, MonadThrow, MonadCatch, MonadMask, MonadUnliftIO)
+type SystemT w m = ReaderT w m
 type System w = SystemT w IO
 
-deriving instance Monad m => MonadReader w (SystemT w m)
-
 -- | A component is defined by specifying how it is stored.
 --   The constraint ensures that stores and components are mapped one-to-one.
 class (Elem (Storage c) ~ c) => Component c where

apecs/src/Apecs/Experimental/Reactive.hs

@@ -35,7 +35,7 @@ module Apecs.Experimental.Reactive
 
 import           Control.Monad
 import           Control.Monad.IO.Class
-import           Control.Monad.Reader
+import           Control.Monad.Trans.Class (lift)
 import qualified Data.Array.IO        as A
 import qualified Data.IntMap.Strict   as IM
 import qualified Data.IntSet          as S

apecs/src/Apecs/Experimental/Stores.hs

@@ -20,7 +20,7 @@ module Apecs.Experimental.Stores
   ( Pushdown(..), Stack(..)
   ) where
 
-import Control.Monad.Reader
+import Control.Monad.Trans.Reader
 import Data.Proxy
 import Data.Semigroup
 

apecs/src/Apecs/Stores.hs

@@ -20,7 +20,7 @@ module Apecs.Stores
 
 import           Control.Monad
 import           Control.Monad.IO.Class
-import           Control.Monad.Reader
+import           Control.Monad.Trans.Class   (lift)
 import           Data.Bits                   (shiftL, (.&.))
 import qualified Data.IntMap.Strict          as M
 import           Data.IORef

apecs/src/Apecs/System.hs

@@ -7,7 +7,8 @@
 module Apecs.System where
 
 import           Control.Monad
-import           Control.Monad.Reader
+import           Control.Monad.Trans.Class (lift)
+import           Control.Monad.Trans.Reader
 import           Data.Proxy
 import qualified Data.Vector.Unboxed  as U
 
@@ -17,7 +18,7 @@ import Apecs.Core
 -- | Run a system in a game world
 {-# INLINE runSystem #-}
 runSystem :: SystemT w m a -> w -> m a
-runSystem sys = runReaderT (unSystem sys)
+runSystem = runReaderT
 
 -- | Run a system in a game world
 {-# INLINE runWith #-}

apecs/src/Apecs/TH.hs

@@ -11,7 +11,7 @@ module Apecs.TH
   ) where
 
 import           Control.Monad        (filterM)
-import           Control.Monad.Reader (asks)
+import           Control.Monad.Trans.Reader (asks)
 import           Data.Traversable     (for)
 import           Language.Haskell.TH
 
@@ -50,7 +50,7 @@ makeWorldNoEC worldName cTypes = do
                          | (j,_) <- enumerate cTypes
                          ]
     [d| instance Monad m => Has $(conT world) m $(conT t) where
-          getStore = let field $pat = $(varE x) in SystemT (asks field)
+          getStore = let field $pat = $(varE x) in asks field
       |]
 
   -- Destructible type synonym

apecs/src/Apecs/Util.hs

@@ -18,7 +18,7 @@ module Apecs.Util (
 
 import           Control.Applicative  (liftA2)
 import           Control.Monad.IO.Class
-import           Control.Monad.Reader
+import           Control.Monad.Trans.Class (lift)
 import           Data.Monoid
 import           Data.Semigroup
 import           System.Mem           (performMajorGC)