Merge branch 'master' of pwning.de:/hgraph

src/Main.hs

@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP             #-}
+{-# LANGUAGE DoAndIfThenElse #-}
 {-# LANGUAGE TemplateHaskell #-}
 -----------------------------------------------------------------------------
 --
@@ -14,9 +15,7 @@
 --
 -----------------------------------------------------------------------------
 
-module Main (
-    main
-) where
+module Main where
 
 import           DCB
 
@@ -28,6 +27,7 @@ import           Data.Array.Repa                as A hiding ((++))
 import           Data.Array.Repa.Repr.Unboxed
 import           Data.ByteString.Char8          (ByteString)
 import qualified Data.ByteString.Char8          as B
+import           Data.Char                      (isSpace)
 import           Data.Either                    (lefts, rights)
 import           Data.Functor.Identity
 import qualified Data.List                      as L
@@ -40,8 +40,18 @@ import           System.Exit                    (exitFailure, exitSuccess)
 import           Test.QuickCheck.All            (quickCheckAll)
 
 
--- TODO: Give createGraph a presized Array and no dynamic [Int].
--- should be createGraph :: T.Text -> Either (Vector Int) T.Text
+-- | Parses the graph
+--   a graph consists of NxN chars layouted like
+--
+--  > 10101
+--  > 01010
+--  > 00100
+--  > 01010
+--  > 10101
+--
+--    * Valid Chars: 0, 1, \\n
+--
+--    * Invalid: \\r
 createGraph :: T.Text -> Either [Int] T.Text
 createGraph input = createGraph' input (Left [])
     where
@@ -49,16 +59,30 @@ createGraph input = createGraph' input (Left [])
         createGraph' a r
             | T.null a = r
             | otherwise =
-                    let next = (createGraph' (T.tail a) r) in        -- flip cases for less function-calls?
-                        case next of
-                            Left xs ->
                     case T.head a of
-                                    '0' -> Left $ 0:xs
-                                    '1' -> Left $ 1:xs
+                        '0' -> createGraph'' 0 (T.tail a) r
+                        '1' -> createGraph'' 1 (T.tail a) r
                         _   -> Right $ T.append (T.pack "cannot parse ") a
+                        -- call recursion as last resort -> ensure not much happens on the heap
+                        where
+                            createGraph'' :: Int -> T.Text -> Either [Int] T.Text -> Either [Int] T.Text
+                            createGraph'' x cs r =
+                                case createGraph' cs r of
+                                    Left xs -> Left (x:xs)
                                     Right errstr ->
                                         Right errstr
 
+-- | Parses the attribute-Matrix
+--   the matrix consists of NxM tab-delimeted double-lines like
+--
+--  > 1     2.3
+--  > -1    2.1
+--  > 4     2.7
+--  > 2.2   -3e-4
+--  > 3     2.3
+--
+--    * Valid: Doubles, Tabs (\\t)
+--
 createAttr :: T.Text -> Either [Double] T.Text
 createAttr input = createAttr' (T.split (=='\t') input) (Left [])
     where
@@ -74,33 +98,32 @@ createAttr input = createAttr' (T.split (=='\t') input) (Left [])
                                   Left rs -> Left (this : rs)
                                   _ -> next))
 
+-- | checks if a given Text is empty ("", whitespaces)
 emptyLine :: T.Text -> Bool
 emptyLine a
     | T.null a        = True
+    | T.all isSpace a = True
     | otherwise       = False
 
-emptyLog :: [T.Text] -> Bool
-emptyLog [] = True
-emptyLog a = False --emptyLine $ foldl True (&&) (map emptyLine a)
-
 -- TODO: implement calculation
 --doCalculation :: Matrix Int -> B.ByteString
 doCalculation graph attr = createOutput attr
 
--- | creates a default-formatted output with "," in between elements
---   and "\n" in between dimensions
---   calls just _createOutput with preset properties
-
---default output with "," within items and "\n" within dimensions
+-- | creates a default-formatted output with \",\" in between elements
+--   and \"\\n\" in between dimensions
+--
+--   calls '_createOutput' with preset properties
 createOutput :: (Unbox a, Show a) => Array U DIM2 a -> B.ByteString
 createOutput a = _createOutput a "," "\n"
 
 -- | creates a formatted output from a DIM2 repa-Array
-
---output Array a with "itt" within items and "lt" within dimensions
+--
+--   * First String is the between-element-separator
+--
+--   * Second String is the between-dimensions-separator
 _createOutput :: (Unbox a, Show a) => Array U DIM2 a -> String -> String -> B.ByteString
 _createOutput a itt lt = B.concat $ L.map B.pack (_createOutput' (extent a) a itt lt)
-
+        where
         _createOutput' :: (Unbox a, Show a) => DIM2 -> Array U DIM2 a -> String -> String -> [String]
         _createOutput' shape@(Z :. si :. sj) a itt lt = [(_createOutput'' shape i 0 a itt) ++ lt | i <- [0..(si - 1)]]
 
@@ -111,6 +134,7 @@ _createOutput'' shape@(Z :. si :. sj) i j a itt
 
 
 -- | gets the length of the Left a.
+--
 --   0 if Left a empty or no valid constructor.
 getLength :: Either [a] T.Text -> Int
 getLength (Left a) = length a
@@ -144,15 +168,18 @@ a +|| b = a `using` b
 -- | checks if the submitted Text is empty. If not it will be printed out and the program aborts
 checkError :: T.Text -> IO ()
 checkError a
-        | T.null a  = return ()
+        | emptyLine a  = return ()
         | otherwise = do
                         B.putStr $ encodeUtf8 $ T.append (T.append (T.pack "Error detected:\n") a) (T.pack "\n\n")
                         exitFailure
 
---change Debug to return () lateron.
+-- | convinience debug-function. Needs to be
+--   changed to return () to disable Debug.
 debug a = putStrLn a
 
-exeMain = do
+
+-- | The main-function to bootstrap our application
+main = do
 --    args <- getArgs
 --    input <- case args of
 --            ["--help"] -> showHelp
@@ -203,18 +230,3 @@ exeMain = do
     ----- CALCULATE & OUTPUT
 
     B.putStr $ doCalculation graph attr
-
-
--- Entry point for unit tests.
-testMain = do
-    allPass <- $quickCheckAll -- Run QuickCheck on all prop_ functions
-    unless allPass exitFailure
-
--- This is a clunky, but portable, way to use the same Main module file
--- for both an application and for unit tests.
--- MAIN_FUNCTION is preprocessor macro set to exeMain or testMain.
--- That way we can use the same file for both an application and for tests.
-#ifndef MAIN_FUNCTION
-#define MAIN_FUNCTION exeMain
-#endif
-main = MAIN_FUNCTION