change trampoline to use Data.Lazy, which did not exist at the time this code was written

Author: jdegoes

MODULE.md

@@ -143,19 +143,7 @@
 
 ### Types
 
-    newtype Delay a where
-      Delay :: Unit -> a -> Delay a
-
-    type Trampoline a = Free Delay a
-
-
-### Type Class Instances
-
-    instance delayApplicative :: Applicative Delay
-
-    instance delayApply :: Apply Delay
-
-    instance delayFunctor :: Functor Delay
+    type Trampoline a = Free Lazy a
 
 
 ### Values

bower.json

@@ -12,9 +12,10 @@
     "dist"
   ],
   "dependencies": {
-    "purescript-control": "0.2.1",
-    "purescript-either": "0.1.3",
+    "purescript-control": "*",
+    "purescript-either": "*",
     "purescript-exists": "*",
-    "purescript-transformers": "0.2.0"
+    "purescript-transformers": "*",
+    "purescript-lazy": "*"
   }
 }

src/Control/Monad/Trampoline.purs

@@ -1,28 +1,18 @@
 module Control.Monad.Trampoline where
 
 import Control.Monad.Free
+import Data.Lazy
 
-newtype Delay a = Delay (Unit -> a)
-
-instance delayFunctor :: Functor Delay where
-  (<$>) f (Delay g) = Delay (const (f (g unit)))
-
-instance delayApply :: Apply Delay where
-  (<*>) (Delay f) (Delay a) = Delay (\_ -> (f unit) (a unit))
-
-instance delayApplicative :: Applicative Delay where
-  pure a = Delay (const a)
-
-type Trampoline a = Free Delay a
+type Trampoline a = Free Lazy a
 
 done :: forall a. a -> Trampoline a
 done = Pure
 
 suspend :: forall a. Trampoline a -> Trampoline a
-suspend a = Free (Delay (const a))
+suspend a = Free (defer (const a))
 
 delay :: forall a. (Unit -> a) -> Trampoline a
-delay a = Free (done <$> Delay a)
+delay a = Free (done <$> defer a)
 
 runTrampoline :: forall a. Trampoline a -> a
-runTrampoline = go (\(Delay f) -> f unit)
+runTrampoline = go force