Add ByteString and Text (lazy variants).

postlude.cabal

@@ -18,6 +18,8 @@ library
   hs-source-dirs:      src
   default-language:    Haskell2010
   build-depends:       base >= 4.7 && < 5,
+                       bytestring == 0.10.8.1,
                        either == 4.4.1.1,
                        mtl == 2.2.1,
+                       text == 1.2.2.2,
                        transformers == 0.5.5.0

src/Postlude.hs

@@ -92,6 +92,10 @@ import Data.Bool as X
   , otherwise
   )
 
+import Data.ByteString.Lazy as X
+  ( ByteString
+  )
+
 import Data.Char as X
   ( Char
   )
@@ -165,6 +169,10 @@ import Data.String as X
   ( String
   )
 
+import Data.Text.Lazy as X
+  ( Text
+  )
+
 import Data.Traversable as X
   ( Traversable, mapM, sequence, sequenceA, traverse
   )
@@ -247,6 +255,8 @@ import GHC.Show as X
 
 import System.Environment as X
   ( getArgs
+  , getEnvironment
+  , getProgName
   )
 
 import System.IO as X