define test to ensure LOC doesn't jump above 400.

tests/loc.hs

@@ -0,0 +1,15 @@
+import Control.Monad
+import System.Exit
+
+main = do foo <- getContents
+          let actual_loc = filter isntcomment $
+                           map (dropWhile (==' ')) $ lines foo
+              loc = length actual_loc
+          putStrLn $ show loc
+          -- uncomment the following to check for mistakes in isntcomment
+          -- putStr $ unlines $ actual_loc
+          when (loc > 400) $ fail "Too many lines of code!"
+
+isntcomment "" = False
+isntcomment ('-':'-':_) = False
+isntcomment _ = True