Use Char's top/bottom, not Int's (#55)

* Use Char's top/bottom, not Int's

* Add changelog

Author: JordanMartinez

CHANGELOG.md

@@ -9,6 +9,7 @@ Breaking changes:
 New features:
 
 Bugfixes:
+- Fix `Char`'s `toEnum` implementation (#55 by @JordanMartinez)
 
 Other improvements:
 

src/Data/Enum.purs

@@ -314,7 +314,7 @@ diag :: forall a. a -> Tuple a a
 diag a = Tuple a a
 
 charToEnum :: Int -> Maybe Char
-charToEnum n | n >= bottom && n <= top = Just (fromCharCode n)
+charToEnum n | n >= toCharCode bottom && n <= toCharCode top = Just (fromCharCode n)
 charToEnum _ = Nothing
 
 foreign import toCharCode :: Char -> Int

test/Test/Data/Enum.purs

@@ -2,7 +2,7 @@ module Test.Data.Enum (testEnum) where
 
 import Prelude
 
-import Data.Enum (class BoundedEnum, class Enum, Cardinality, defaultCardinality, defaultFromEnum, defaultToEnum, downFrom, downFromIncluding, enumFromThenTo, enumFromTo, upFrom, upFromIncluding)
+import Data.Enum (class BoundedEnum, class Enum, Cardinality, defaultCardinality, defaultFromEnum, defaultToEnum, downFrom, downFromIncluding, enumFromThenTo, enumFromTo, fromEnum, toEnum, upFrom, upFromIncluding)
 import Data.Maybe (Maybe(..))
 import Data.Newtype (unwrap)
 import Data.NonEmpty ((:|))
@@ -194,3 +194,15 @@ testEnum = do
     { actual: defaultFromEnum (Upto100k 100000)
     , expected: 100000
     }
+  
+  log "charToEnum"
+  assertEqual
+    { actual: Nothing :: Maybe Char
+    , expected: toEnum (top :: Int)
+    }
+
+  log "charToEnum"
+  assertEqual
+    { actual: Just 'a'
+    , expected: toEnum (fromEnum 'a')
+    }