Merge simple demo

brick.cabal

@@ -46,6 +46,17 @@ executable brick
                        data-default,
                        lens
 
+executable brick-minimal
+  hs-source-dirs:      programs
+  ghc-options:         -threaded -Wall -fno-warn-unused-do-bind
+  default-language:    Haskell2010
+  main-is:             Minimal.hs
+  build-depends:       base,
+                       brick,
+                       vty >= 5.2.9,
+                       data-default,
+                       lens
+
 executable brick-rogue
   buildable:           False
   hs-source-dirs:      programs

programs/Minimal.hs

@@ -0,0 +1,7 @@
+module Main where
+
+import Brick.Main
+import Brick.Prim
+
+main :: IO ()
+main = simpleMain [Txt "Hello, world!"]

src/Brick/Main.hs

@@ -4,6 +4,8 @@ module Brick.Main
   , defaultMain
   , defaultMainWithVty
 
+  , simpleMain
+
   , supplyVtyEvents
   , withVty
   , runVty
@@ -30,6 +32,7 @@ import Graphics.Vty
   , nextEvent
   , mkVty
   )
+import System.Exit (exitSuccess)
 
 import Brick.Prim (Prim)
 import Brick.Prim.Internal (renderFinal)
@@ -50,6 +53,13 @@ instance Default (App a e) where
 defaultMain :: App a Event -> a -> IO ()
 defaultMain = defaultMainWithVty (mkVty def)
 
+simpleMain :: [Prim ()] -> IO ()
+simpleMain ls =
+    let app = def { appDraw = const ls
+                  , appHandleEvent = const $ const exitSuccess
+                  }
+    in defaultMain app ()
+
 defaultMainWithVty :: IO Vty -> App a Event -> a -> IO ()
 defaultMainWithVty buildVty app initialState = do
     chan <- newChan