unit tests, started on pattern matching

src/Main.hs

@@ -3,7 +3,6 @@
 module Main where
 
 -- import           Codegen.Codegen           (compile)
-import           GHC.IO.Handle.Text      (hPutStrLn)
 import           Grammar.ErrM            (Err)
 import           Grammar.Par             (myLexer, pProgram)
 import           Grammar.Print           (printTree)
@@ -12,7 +11,6 @@ import           Grammar.Print           (printTree)
 import           Renamer.Renamer         (rename)
 import           System.Environment      (getArgs)
 import           System.Exit             (exitFailure, exitSuccess)
-import           System.IO               (stderr)
 import           TypeChecker.TypeChecker (typecheck)
 
 main :: IO ()
@@ -25,32 +23,28 @@ main' :: String -> IO ()
 main' s = do
     file <- readFile s
 
-    printToErr "-- Parse Tree -- "
+    putStrLn "-- Parse Tree -- "
     parsed <- fromSyntaxErr . pProgram $ myLexer file
-    printToErr $ printTree parsed
+    putStrLn $ printTree parsed
 
-    printToErr "\n-- Renamer --"
+    putStrLn "\n-- Renamer --"
     let renamed = rename parsed
-    printToErr $ printTree renamed
+    putStrLn $ printTree renamed
 
-    printToErr "\n-- TypeChecker --"
+    putStrLn "\n-- TypeChecker --"
     typechecked <- fromTypeCheckerErr $ typecheck renamed
-    printToErr $ printTree typechecked
+    putStrLn $ printTree typechecked
 
-    -- printToErr "\n-- Lambda Lifter --"
+    -- putStrLn "\n-- Lambda Lifter --"
     -- let lifted = lambdaLift typechecked
-    -- printToErr $ printTree lifted
+    -- putStrLn $ printTree lifted
 
-    -- printToErr "\n -- Printing compiler output to stdout --"
+    -- putStrLn "\n -- Printing compiler output to stdout --"
     -- compiled <- fromCompilerErr $ compile lifted
     -- putStrLn compiled
-    -- writeFile "llvm.ll" compiled
 
     exitSuccess
 
-printToErr :: String -> IO ()
-printToErr = hPutStrLn stderr
-
 fromCompilerErr :: Err a -> IO a
 fromCompilerErr =
     either