WIP on randomPhrase function

Spintax.cabal

@@ -20,6 +20,7 @@ library
   other-modules:     Text.Spintax.RandomPhrase
   build-depends:     attoparsec   >= 0.12.1.6 && < 0.15
                    , base         >= 4.7 && < 5
+                   , either       >= 5 && < 6
                    , extra        >= 1.4.3 && < 1.9
                    , mtl          >= 2.2.1 && < 2.4
                    , mwc-random   >= 0.13.3.2 && < 0.16

src/Text/Spintax/RandomPhrase.hs

@@ -1,15 +1,21 @@
 module Text.Spintax.RandomPhrase where
 
-import qualified Data.Text    as T
+import           Data.Either.Combinators (mapRight)
+import qualified Data.Text               as T
 import           Text.Spintax
 
-type RandomPhrase = T.Text
+newtype RandomPhrase = RandomPhrase { unRandomPhrase :: T.Text }
+
+instance Show RandomPhrase where
+  show (RandomPhrase t) = show t
 
 -- | Generate random passphrase or unique id
 --
 -- >λ> randomPhrase "-" [["blacky","monk","gillespie","coltrane"],["apple","apricot","banana","coconut"],["kant","hegel","husserl","habermas"]]
 -- > Right "coltrane-coconut-kant"
 --
 randomPhrase :: T.Text -> [[T.Text]] -> IO (Either String RandomPhrase)
-randomPhrase s ls = spintax $ writeSpintaxExpression s $ writeSpintaxAlternative <$> ls
+randomPhrase s ls = do
+  r <- spintax $ writeSpintaxExpression s $ writeSpintaxAlternative <$> ls
+  pure (mapRight RandomPhrase r)