initialize random number generator

app/Main.hs

@@ -26,8 +26,9 @@ import Brick (defaultMain)
 import Control.Monad (void)
 
 import Password.App
+import Password.App.Types
 
 main :: IO ()
-main = void $ defaultMain passmanApp ()
+main = void $ mkInitialState >>= defaultMain passmanApp
 
 --jl

passman.cabal

@@ -4,7 +4,7 @@ cabal-version: 2.2
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 235d7c20ee589946f5e0cd199cca106191a300f9f24b023a6ef074c197c9861b
+-- hash: d742af1f90e36896cfb5979f267f1ef87b81fb7e603c8c72ccc0c8e7a382a408
 
 name:           passman
 version:        0.3.1.1
@@ -27,6 +27,7 @@ library
   exposed-modules:
       Password
       Password.App
+      Password.App.Types
   other-modules:
       Paths_passman
   autogen-modules:

src/Password/App.hs

@@ -36,8 +36,10 @@ import Brick
   , style
   )
 
+import Password.App.Types
+
 -- | The main application
-passmanApp :: App () () ()
+passmanApp :: App AppState () ()
 passmanApp = App
   { appDraw         = drawFunc
   , appChooseCursor = neverShowCursor
@@ -46,10 +48,10 @@ passmanApp = App
   , appAttrMap      = const $ attrMap (style 0) []
   }
 
-drawFunc :: () -> [Widget ()]
+drawFunc :: AppState -> [Widget ()]
 drawFunc = const [emptyWidget]
 
-eventHandler :: BrickEvent () () -> EventM () () ()
+eventHandler :: BrickEvent () () -> EventM () AppState ()
 eventHandler = const halt
 
 --jl

src/Password/App/Types.hs

@@ -0,0 +1,43 @@
+{-|
+
+Module:      Password.App.Types
+Description: data types used by the application
+Copyright:   (C) Jonathan Lamothe
+License:     LGPLv3 (or later)
+Maintainer:  jonathan@jlamothe.net
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as
+published by the Free Software Foundation, either version 3 of the
+License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this program.  If not, see
+<https://www.gnu.org/licenses/>.
+
+-}
+
+module Password.App.Types (
+  AppState (..),
+  mkInitialState
+  ) where
+
+import Control.Monad.IO.Class (MonadIO)
+import System.Random (StdGen, initStdGen)
+
+-- | The application state
+newtype AppState = AppState
+  { _randGen :: StdGen
+  -- ^ The random number generator
+  } deriving (Eq, Show)
+
+-- | Builds an initial state
+mkInitialState :: MonadIO m => m AppState
+mkInitialState = AppState <$> initStdGen
+
+--jl