add files from home for previous chapters and sandboxes

29 files changed, 370 insertions, 0 deletions

diff --git a/appendtodo.hs b/appendtodo.hs
new file mode 100644
index 0000000..6c3970c
--- /dev/null
+++ b/appendtodo.hs
@@ -0,0 +1,8 @@
+import System.IO
+
+main = do
+    todoItem <- getLine
+    if null todoItem then return () 
+        else (do 
+            appendFile "todo.txt" (todoItem ++ "\n")
+            main)
diff --git a/arg-test.hs b/arg-test.hs
new file mode 100644
index 0000000..f986ad7
--- /dev/null
+++ b/arg-test.hs
@@ -0,0 +1,11 @@
+import System.Environment
+import Data.List
+
+main = do
+    args <- getArgs
+    progName <- getProgName
+    putStrLn "The arguments are:"
+    mapM putStrLn args
+    putStrLn "The program name is:"
+    putStrLn progName
+
diff --git a/capscont.hs b/capscont.hs
new file mode 100644
index 0000000..2277d3b
--- /dev/null
+++ b/capscont.hs
@@ -0,0 +1,5 @@
+import Data.Char
+
+main = do
+    contents <- getContents
+    putStr $ map toUpper contents
diff --git a/capslock.hs b/capslock.hs
new file mode 100644
index 0000000..be34c83
--- /dev/null
+++ b/capslock.hs
@@ -0,0 +1,6 @@
+import Control.Monad
+import Data.Char
+
+main = forever $ do
+    l <- getLine
+    putStrLn $ map toUpper l
diff --git a/charlist.hs b/charlist.hs
new file mode 100644
index 0000000..d434a94
--- /dev/null
+++ b/charlist.hs
@@ -0,0 +1,2 @@
+newtype CharList = CharList { getCharList :: [Char] } deriving (Eq, Show)
+
diff --git a/copyFile.hs b/copyFile.hs
new file mode 100644
index 0000000..0835b0e
--- /dev/null
+++ b/copyFile.hs
@@ -0,0 +1,21 @@
+import System.Environment
+import System.Directory
+import System.IO
+import Control.Exception
+import qualified Data.ByteString.Lazy as B
+
+main = do
+    (fileName1:fileName2:_) <- getArgs
+    copy fileName1 fileName2
+
+copy source dest = do
+    contents <- B.readFile source
+    bracketOnError
+        (openTempFile "." "temp")
+        (\(tempName, tempHandle) -> do
+            hClose tempHandle
+            removeFile tempName)
+        (\(tempName, tempHandle) -> do
+            B.hPutStr tempHandle contents
+            hClose tempHandle
+            renameFile tempName dest)
diff --git a/fac.hs b/fac.hs
new file mode 100644
index 0000000..dce8a26
--- /dev/null
+++ b/fac.hs
@@ -0,0 +1,6 @@
+facn a b = fac a b 1
+
+fac a 0 c = c
+fac a b c = fac (a*a) (div b 2) (c*(if odd b then a else 1))
+
+--fibn a = fib a 1 1 1 1 0
diff --git a/fib.hs b/fib.hs
new file mode 100644
index 0000000..647f75e
--- /dev/null
+++ b/fib.hs
@@ -0,0 +1,13 @@
+fib n = fi n 1 1
+
+fi 1 x y = x
+fi a x y = fi (a-1) (x+y) x
+
+ffib n = ffi n 1 1 1 0 1 0
+
+ffi 1 a b c d x y = (a*x + b*y)
+ffi n a b c d x y = 
+    if odd n 
+        then ffi (div n 2) (a*a + b*c) (a*b + b*d) (a*c + c*d) (d*d + b*c) (a*x + b*y) (c*x + d*y)
+        else ffi (div n 2) (a*a + b*c) (a*b + b*d) (a*c + c*d) (d*d + b*c) x y
+
diff --git a/girlfriend.hs b/girlfriend.hs
new file mode 100644
index 0000000..27a87f4
--- /dev/null
+++ b/girlfriend.hs
@@ -0,0 +1,6 @@
+import System.IO
+
+main = do
+    withFile "girlfriend.txt" ReadMode (\handle -> do
+        contents <- hGetContents handle
+        putStr contents)
diff --git a/girlfriend.txt b/girlfriend.txt
new file mode 100644
index 0000000..c3f3b39
--- /dev/null
+++ b/girlfriend.txt
@@ -0,0 +1,4 @@
+Hey! Hey! You! You!
+I don't like your girlfriend!
+No way! No way!
+I think you need a new one!
diff --git a/girlfriend1.txt b/girlfriend1.txt
new file mode 100644
index 0000000..c3f3b39
--- /dev/null
+++ b/girlfriend1.txt
@@ -0,0 +1,4 @@
+Hey! Hey! You! You!
+I don't like your girlfriend!
+No way! No way!
+I think you need a new one!
diff --git a/helloworld.hs b/helloworld.hs
new file mode 100644
index 0000000..485eb34
--- /dev/null
+++ b/helloworld.hs
@@ -0,0 +1,5 @@
+main = do
+    putStrLn "Hello, world !"
+    putStrLn "Your name?"
+    name <- getLine
+    putStrLn ("Hey, "++ name ++", you rock!")
diff --git a/hl.hs b/hl.hs
new file mode 100644
index 0000000..6273b5f
--- /dev/null
+++ b/hl.hs
@@ -0,0 +1,8 @@
+data HL = HL Float Float
+
+instance Eq HL where
+    (==) (HL a1 b1) (HL a2 b2) = a1*b1==a2*b2
+
+instance Show HL where
+    show (HL a b) = (show a) ++ ":" ++ (show b) ++ "->"
+        ++ (show $ sqrt(a**2+b**2))
diff --git a/lengthComp.hs b/lengthComp.hs
new file mode 100644
index 0000000..e4457d2
--- /dev/null
+++ b/lengthComp.hs
@@ -0,0 +1,4 @@
+import Data.Monoid
+
+lengthComp :: String -> String -> Ordering
+lengthComp x y = (length x `compare` length y) `mappend` (x `compare` y)
diff --git a/pole.hs b/pole.hs
new file mode 100644
index 0000000..4ec54d4
--- /dev/null
+++ b/pole.hs
@@ -0,0 +1,27 @@
+type Birds = Int
+type Pole = (Birds, Birds)
+
+landLeft :: Birds -> Pole -> Maybe Pole
+landLeft n (left, right)
+    | abs((left+n) - right) < 4 = Just (left + n, right)
+    | otherwise                 = Nothing
+
+landRight :: Birds -> Pole -> Maybe Pole
+landRight n (left, right) 
+    | abs((right+n) - left) < 4 = Just (left, right + n)
+    | otherwise                 = Nothing
+
+foo = do
+    x <- Just 3
+    y <- Just "!"
+    Just (show x ++ y)
+
+routine = do
+    start <- return (0,0)
+    first <- landLeft 2 start
+    second <- landRight 2 first
+    landLeft 1 second
+
+wopwop = do
+    (x:xs) <- Just ""
+    return x
diff --git a/prime.hs b/prime.hs
new file mode 100644
index 0000000..2407280
--- /dev/null
+++ b/prime.hs
@@ -0,0 +1,11 @@
+prime = [x| x<-[2,3..], null [y|y<-[2,3..floor $ sqrt(fromIntegral x)],mod x y ==0] ]
+
+primes r [] = r 
+primes r (p:ps) = if null [y|y<-r,mod p y == 0] 
+    then p:(primes (p:r) ps) 
+    else primes r ps
+
+pr = 2:(ps [3,5..])
+
+ps (x:xr) = x:(ps (filter rem xr))
+    where rem y = (mod y x) /=0
diff --git a/reverse.hs b/reverse.hs
new file mode 100644
index 0000000..cc82509
--- /dev/null
+++ b/reverse.hs
@@ -0,0 +1,10 @@
+main = do
+    line <- getLine
+    if null line
+        then return ()
+        else do
+            putStrLn $ reverseWords line
+            main
+
+reverseWords :: String -> String
+reverseWords = unwords . map reverse . words
diff --git a/rmtodo.hs b/rmtodo.hs
new file mode 100644
index 0000000..2507d86
--- /dev/null
+++ b/rmtodo.hs
@@ -0,0 +1,21 @@
+import System.IO  
+import System.Directory  
+import Data.List
+
+main = do        
+    handle <- openFile "todo.txt" ReadMode  
+    (tempName, tempHandle) <- openTempFile "." "temp"  
+    contents <- hGetContents handle  
+    let todoTasks = lines contents     
+        numberedTasks = zipWith (\n line -> show n ++ " - " ++ line) [0..] todoTasks     
+    putStrLn "These are your TO-DO items:"  
+    putStr $ unlines numberedTasks  
+    putStrLn "Which one do you want to delete?"     
+    numberString <- getLine     
+    let number = read numberString     
+        newTodoItems = delete (todoTasks !! number) todoTasks     
+    hPutStr tempHandle $ unlines newTodoItems  
+    hClose handle  
+    hClose tempHandle  
+    removeFile "todo.txt"  
+    renameFile tempName "todo.txt"
diff --git a/rmtodo1.hs b/rmtodo1.hs
new file mode 100644
index 0000000..37b6d9b
--- /dev/null
+++ b/rmtodo1.hs
@@ -0,0 +1,19 @@
+import System.IO
+import System.Directory
+import Data.List
+
+main = do
+    contents <- readFile "todo.txt"
+    let todoTasks = lines contents
+        numberedTasks = zipWith (\n line -> show n ++ " - " ++ line) [0..] todoTasks
+    putStrLn "These are your TO-DO items:"
+    mapM_ putStrLn numberedTasks
+    putStrLn "Which one do you want to delete?"
+    numberString <- getLine
+    let number = read numberString
+        newTodoItems = unlines $ delete (todoTasks !! number) todoTasks
+    (tempName, tempHandle) <- openTempFile "." "temp"
+    hPutStr tempHandle newTodoItems
+    hClose tempHandle
+    removeFile "todo.txt"
+    renameFile tempName "todo.txt"
diff --git a/rmtodo2.hs b/rmtodo2.hs
new file mode 100644
index 0000000..3d2e249
--- /dev/null
+++ b/rmtodo2.hs
@@ -0,0 +1,25 @@
+import System.IO
+import System.Directory
+import Data.List
+import Control.Exception
+
+main = do
+    contents <- readFile "todo.txt"
+    let todoTasks = lines contents
+        numberedTasks = zipWith (\n line -> show n ++ " - " ++ line) [0..] todoTasks
+    putStrLn "These are your TO-DO items:"
+    mapM_ putStrLn numberedTasks
+    putStrLn "Which one do you want to delete?"
+    numberString <- getLine
+    let number = read numberString
+        newTodoItems = unlines $ delete (todoTasks !! number) todoTasks
+    bracketOnError (openTempFile "." "temp")
+        (\(tempName,tempHandle) -> do
+            hClose tempHandle
+            removeFile tempName)
+        (\(tempName,tempHandle) -> do
+            hPutStr tempHandle newTodoItems
+            hClose tempHandle
+            removeFile "todo.txt"
+            renameFile tempName "todo.txt")
+
diff --git a/sandbox.hs b/sandbox.hs
new file mode 100644
index 0000000..f1a3213
--- /dev/null
+++ b/sandbox.hs
@@ -0,0 +1,28 @@
+import Control.Monad
+import Data.Monoid
+
+dotest x = do
+    if x then return "Test"
+         else return "OK" 
+
+type KnightPos = (Int, Int)
+
+moveKnight :: KnightPos -> [KnightPos]
+moveKnight (c, r) = do
+    (c', r') <- [(c+2,r-1),(c+2,r+1),(c-2,r-1),(c-2,r+1)
+            ,(c+1,r-2),(c+1,r+2),(c-1,r-2),(c-1,r+2)]
+    guard (c' `elem` [1..8] && r' `elem` [1..8])
+    return (c', r')
+
+filterDup :: [KnightPos] -> [KnightPos]
+filterDup [] = []
+filterDup (x:xr) = x:(filterDup $ filter (x/=) xr)
+
+singleStep x = filterDup $ x >>= moveKnight
+
+multiStep :: Int -> [KnightPos] -> [KnightPos]
+multiStep 0 x = x
+multiStep n x = multiStep (n-1) (singleStep x)
+
+applyLog :: (Monoid m) => (a, m) -> (a -> (b, m)) -> (b, m)
+applyLog (x, log) f = let (y, newLog) = f x in (y, log `mappend` newLog)
diff --git a/sequenceA.hs b/sequenceA.hs
new file mode 100644
index 0000000..f918a44
--- /dev/null
+++ b/sequenceA.hs
@@ -0,0 +1,4 @@
+import Control.Applicative
+
+sequenceA :: (Applicative f) => [f a] -> f [a]
+sequenceA = foldr (liftA2 (:)) (pure [])
diff --git a/shape.hs b/shape.hs
new file mode 100644
index 0000000..0f8eca1
--- /dev/null
+++ b/shape.hs
@@ -0,0 +1,6 @@
+data Shape = Circle Float Float Float | Rectangle Float Float Float Float 
+    deriving (Show)
+
+area :: Shape -> Float
+area (Circle _ _ r) = pi * r ^ 2
+area (Rectangle x1 y1 x2 y2) = (abs $ x1 - x2) * (abs $ y1 - y2)
diff --git a/shortlines.hs b/shortlines.hs
new file mode 100644
index 0000000..267e595
--- /dev/null
+++ b/shortlines.hs
@@ -0,0 +1,7 @@
+import Data.Char
+
+main = do
+    contents <- getContents
+    let shortLines = unlines . filter ((<10).length) . lines in
+        putStr $ shortLines contents
+
diff --git a/test.hs b/test.hs
new file mode 100644
index 0000000..1f2dca6
--- /dev/null
+++ b/test.hs
@@ -0,0 +1,2 @@
+isSB "Phil" = "yes"
+isSB a = "no"
diff --git a/todo.hs b/todo.hs
new file mode 100644
index 0000000..2cb21c1
--- /dev/null
+++ b/todo.hs
@@ -0,0 +1,52 @@
+import System.Environment
+import System.Directory
+import System.IO
+import Data.List
+import Control.Exception
+import Control.Monad(when)
+
+fileName = "todo.txt"
+
+dispatch :: String -> String -> IO ()
+dispatch file "add" = add file
+dispatch file "view" = view file
+dispatch file "rm" = remove file
+dispatch file _ = do
+    putStrLn "Operations supported:\nadd - Append Item\nview - Inspect Item\nrm - Remove Item"
+
+view file = do
+    contents <- readFile file
+    let todoTasks = lines contents
+    putStr $ unlines $ number todoTasks
+
+add file = do
+    todoItem <- getLine
+    when (not $ null todoItem) (do
+        appendFile file todoItem)
+
+remove file = do
+    contents <- readFile file
+    numberString <- getLine
+    let todoTasks = lines contents
+        number = read numberString
+        newTodoList = unlines $ delete (todoTasks !! number) todoTasks
+    bracketOnError (openTempFile "." "temp") 
+        (\(tempName,tempHandle) -> do
+            hClose tempHandle
+            removeFile tempName)
+        (\(tempName,tempHandle) -> do
+            hPutStr tempHandle newTodoList
+            hClose tempHandle
+            removeFile file
+            renameFile tempName file)
+
+
+number task = zipWith (\n line -> show n ++ " - " ++ line) [0..] task
+
+main = do
+    line <- getLine
+    if null line then return ()
+        else (do
+            dispatch fileName line
+            main)
+
diff --git a/todo.txt b/todo.txt
new file mode 100644
index 0000000..cd5c47b
--- /dev/null
+++ b/todo.txt
@@ -0,0 +1,3 @@
+Dust the dog
+Take salad out of the oven
+Iron the dishes
\ No newline at end of file
diff --git a/traffic.hs b/traffic.hs
new file mode 100644
index 0000000..f409de3
--- /dev/null
+++ b/traffic.hs
@@ -0,0 +1,14 @@
+data TrafficLight = Red | Yellow | Green
+
+instance Eq TrafficLight where
+    Red == Red = True
+    Yellow == Yellow = True
+    Green == Green = True
+    _ == _ = False
+
+instance Show TrafficLight where
+    show Red = "Red light"
+    show Yellow = "Yellow light"
+    show Green = "Green light"
+
+data Either a b = Left a | Right b
diff --git a/tree.hs b/tree.hs
new file mode 100644
index 0000000..50f4774
--- /dev/null
+++ b/tree.hs
@@ -0,0 +1,38 @@
+import Data.Monoid
+import qualified Data.Foldable as F
+
+data Tree a = Empty | Node a (Tree a) (Tree a)
+    deriving (Show)
+
+instance F.Foldable Tree where
+    foldMap f Empty = mempty
+    foldMap f (Node x l r) = F.foldMap f l `mappend`
+                             f x `mappend`
+                             F.foldMap f r
+
+singleton :: a -> Tree a
+singleton x = Node x Empty Empty
+
+treeInsert :: (Ord a) => a -> Tree a -> Tree a
+treeInsert x Empty = singleton x
+treeInsert x (Node a left right)
+    | x == a = Node x left right
+    | x < a  = Node a (treeInsert x left) right
+    | x > a  = Node a left (treeInsert x right)
+
+treeElem :: (Ord a) => a -> Tree a -> Bool
+treeElem x Empty = False
+treeElem x (Node a left right)
+    | x == a = True
+    | x < a  = treeElem x left
+    | x > a  = treeElem x right
+
+testTree = Node 6
+            (Node 3
+                (Node 1 Empty Empty)
+                (Node 5 Empty Empty)
+            )
+            (Node 9
+                (Node 8 Empty Empty)
+                (Node 10 Empty Empty)
+            )