Vary the length of generated strings

Author: garyb

src/Data/String/Gen.purs

@@ -2,14 +2,16 @@ module Data.String.Gen where
 
 import Prelude
 
-import Control.Monad.Gen (class MonadGen, unfoldable)
+import Control.Monad.Gen (class MonadGen, chooseInt, unfoldable, sized, resize)
 import Control.Monad.Rec.Class (class MonadRec)
 import Data.Char.Gen as CG
 import Data.String as S
 
 -- | Generates a string using the specified character generator.
 genString :: forall m. MonadRec m => MonadGen m => m Char -> m String
-genString = map S.fromCharArray <<< unfoldable
+genString genChar = sized \size -> do
+  newSize <- chooseInt 1 size
+  resize (const newSize) $ S.fromCharArray <$> unfoldable genChar
 
 -- | Generates a string using characters from the Unicode basic multilingual
 -- | plain.