Add Frege language

What is Frege?
-------------
Frege is a non-strict, pure functional programming language in the spirit of Haskell for the JVM.
It enjoys a strong static type system with type inference.
Higher rank types are supported, though type annotations are required for that.

Frege programs are compiled to Java and run in a JVM.
Existing Java Classes and Methods can be used seamlessly from Frege.

The Frege programming language is named after and in honor of Gottlob Frege.

Project State:
-------------
The compiler, an Eclipse plugin and a provisional version of the documentation can be downloaded
from here https://github.com/Frege/frege/releases.

The REPL can be downloaded from here
https://github.com/Frege/frege-repl/releases.

An online REPL is running here
http://try.frege-lang.org/.

Examples:
--------
1) Command Line Clock: https://github.com/Frege/frege/blob/master/examples/CommandLineClock.fr
2) Brainfuck: https://github.com/Frege/frege/blob/master/examples/Brainfuck.fr
3) Concurrency: https://github.com/Frege/frege/blob/master/examples/Concurrent.fr
4) Sudoku: https://github.com/Frege/frege/blob/master/examples/Sudoku.fr
5) Java Swing examples: https://github.com/Frege/frege/blob/master/examples/SwingExamples.fr

samples/Frege/Concurrent.fr

@@ -0,0 +1,147 @@
+module examples.Concurrent where
+
+import System.Random
+import Java.Net (URL)
+import Control.Concurrent as C
+
+main2 args = do
+    m <- newEmptyMVar
+    forkIO do
+        m.put 'x'
+        m.put 'y' 
+        m.put 'z'
+    replicateM_ 3 do
+        c <- m.take
+        print "got: "
+        println c  
+        
+            
+example1 = do
+    forkIO (replicateM_ 100000 (putChar 'a'))
+    replicateM_ 100000 (putChar 'b')
+
+example2 =  do
+    s <- getLine
+    case s.long of
+        Right n -> forkIO (setReminder n) >> example2
+        Left _  -> println ("exiting ...")
+    
+setReminder :: Long -> IO ()
+setReminder n = do
+        println ("Ok, I remind you in " ++ show n ++ " seconds")
+        Thread.sleep (1000L*n)
+        println (show n ++ " seconds is up!")
+
+table = "table"
+            
+mainPhil _ = do
+    [fork1,fork2,fork3,fork4,fork5] <- mapM MVar.new [1..5]
+    forkIO (philosopher "Kant" fork5 fork1)
+    forkIO (philosopher "Locke" fork1 fork2)
+    forkIO (philosopher "Wittgenstein" fork2 fork3)
+    forkIO (philosopher "Nozick" fork3 fork4)
+    forkIO (philosopher "Mises" fork4 fork5)
+    return ()    
+
+philosopher :: String -> MVar Int -> MVar Int -> IO ()
+philosopher me left right = do
+    g <- Random.newStdGen
+    let phil g  = do
+            let (tT,g1) = Random.randomR (60L, 120L) g
+                (eT, g2)  = Random.randomR (80L, 160L) g1
+                thinkTime = 300L * tT
+                eatTime   = 300L * eT
+    
+            println(me ++ " is going to the dining room and takes his seat.") 
+            fl <- left.take            
+            println (me ++ " takes up left fork (" ++ show fl ++ ")")
+            rFork <- right.poll
+            case rFork of
+                Just fr -> do 
+                    println (me ++ " takes up right fork. (" ++ show fr ++ ")") 
+                    println (me ++ " is going to eat for " ++ show eatTime ++ "ms")
+                    Thread.sleep eatTime
+                    println (me ++ " finished eating.")
+                    right.put fr
+                    println (me ++ " took down right fork.")
+                    left.put fl
+                    println (me ++ " took down left fork.")
+                    table.notifyAll 
+                    println(me ++ " is going to think for " ++ show thinkTime ++ "ms.")
+                    Thread.sleep thinkTime
+                    phil g2
+                Nothing -> do
+                    println (me ++ " finds right fork is already in use.")
+                    left.put fl
+                    println (me ++ " took down left fork.")
+                    table.notifyAll
+                    println (me ++ " is going to the bar to await notifications from table.")
+                    table.wait
+                    println (me ++ " got notice that something changed at the table.")
+                    phil g2
+            
+        inter :: InterruptedException -> IO ()
+        inter _ = return ()        
+    
+    phil g `catch` inter
+
+    
+getURL xx = do
+        url <- URL.new xx 
+        con <- url.openConnection
+        con.connect
+        is  <- con.getInputStream
+        typ <- con.getContentType
+        -- stderr.println ("content-type is " ++ show typ) 
+        ir  <- InputStreamReader.new is (fromMaybe "UTF-8" (charset typ))
+            `catch` unsupportedEncoding is 
+        br  <- BufferedReader.new ir
+        br.getLines
+    where
+        unsupportedEncoding :: InputStream -> UnsupportedEncodingException -> IO InputStreamReader
+        unsupportedEncoding is x = do
+            stderr.println x.catched
+            InputStreamReader.new is "UTF-8"
+            
+        charset ctyp = do
+            typ <- ctyp
+            case typ of
+                m~´charset=(\S+)´ -> m.group 1
+                _ -> Nothing
+
+    
+type SomeException = Throwable
+
+main ["dining"] = mainPhil []
+        
+main _ =  do
+    m1 <- MVar.newEmpty
+    m2 <- MVar.newEmpty
+    m3 <- MVar.newEmpty
+    
+    forkIO do
+        r <- (catchAll . getURL) "http://www.wikipedia.org/wiki/Haskell"
+        m1.put r
+    
+    forkIO do
+        r <- (catchAll . getURL) "htto://www.wikipedia.org/wiki/Java"
+        m2.put r
+    
+    forkIO do
+        r <- (catchAll . getURL) "http://www.wikipedia.org/wiki/Frege"
+        m3.put r
+    
+    r1 <- m1.take
+    r2 <- m2.take
+    r3 <- m3.take
+    println (result r1, result r2, result r3)
+    -- case r3 of
+    --     Right ss -> mapM_ putStrLn ss
+    --     Left _   -> return ()
+  where
+    result :: (SomeException|[String]) -> (String|Int)
+    result (Left x)  = Left x.getClass.getName
+    result (Right y) = (Right . sum . map length)  y
+    -- mapM_ putStrLn r2
+
+