1 files changed, 46 insertions, 18 deletions

diff --git a/AufgabeFFP7.hs b/AufgabeFFP7.hs
index fc9d594..43e8014 100644
--- a/AufgabeFFP7.hs
+++ b/AufgabeFFP7.hs
@@ -2,7 +2,7 @@ module AufgabeFFP7
 where
 
 import Data.Char
-import Data.List hiding ((\\), insert)
+import Data.List hiding ((\\), insert, delete)
 import Test.QuickCheck
 
 type Buffer = (Int, String)
@@ -55,26 +55,29 @@ insertI :: Char -> BufferI -> BufferI
 insertI c (beforeC, afterC) = ([c] ++ beforeC, afterC)
 
 -- delete character before cursor
---TODO deleteI :: BufferI -> BufferI
+deleteI :: BufferI -> BufferI
+deleteI (beforeC, "") = (beforeC, "")
+deleteI (beforeC, last:afterC) = (beforeC, afterC)
 
 -- move cursor left one character
 leftI :: BufferI -> BufferI
-leftI ([], afterC) = ([], afterC)
+leftI ("", afterC) = ("", afterC)
 leftI (last:beforeC, afterC) = (beforeC, [last] ++ afterC)
 
 -- move cursor right one character
---TODO rightI :: BufferI -> BufferI
+rightI :: BufferI -> BufferI
+rightI (beforeC, "") = (beforeC, "")
+rightI (beforeC, last:afterC) = ([last] ++ beforeC, afterC)
 
 -- is cursor at left end?
 atLeftI :: BufferI -> Bool
-atLeftI ([], _) = True
-atLeftI (_, _) = False
+atLeftI ("", _) = True
+atLeftI (_, _)  = False
 
 -- is cursor at right end?
 atRightI :: BufferI -> Bool
-atRightI (_, []) = True
-atRightI (_, _) = False
-
+atRightI (_, "") = True
+atRightI (_, _)  = False
 
 --------------------------------------------------------------------------------
 
@@ -88,25 +91,50 @@ retrieve (beforeC, afterC) = (length beforeC, (reverse beforeC) ++ afterC)
 bufEqual :: BufferI -> Buffer -> Bool
 bufEqual bi b = (retrieve bi) == b
 
+(<==>) = bufEqual
+
 -- generator for equal data
 genEqualBuf :: Gen(Buffer, BufferI)
-genEqualBuf = do s <- arbitrary ; c <- choose (0, length s) ; return ( (c, s), revFst (splitAt c s) )
-                where 
-                revFst = \(a, b) -> (reverse a, b)
+genEqualBuf = do
+  s <- arbitrary
+  c <- choose (0, length s)
+  return ((c, s), revFst (splitAt c s))
+  where
+    revFst = \(a, b) -> (reverse a, b)
 
 instance Arbitrary Char where
-        arbitrary = elements $ ['a'..'z'] ++ ['A'..'Z']
+  arbitrary = elements $ ['a'..'z'] ++ ['A'..'Z']
+
+prop_empty :: Bool
+prop_empty = emptyI <==> empty
 
 -- naive insert test, will exhaust
-prop_insert :: BufferI -> Buffer -> Char -> Property
-prop_insert bi b c = bufEqual bi b
-        ==> bufEqual (insertI c bi) (insert c b)
+--prop_insert :: BufferI -> Buffer -> Char -> Property
+--prop_insert bi b c = bi <==> b
+--  ==> insertI c bi <==> insert c b
+
+prop_insert :: BufferI -> Char -> Bool
+prop_insert bi c = insertI c bi <==> insert c (retrieve bi)
 
 -- use equal data generator
 prop_insert2 :: Char -> Property
-prop_insert2 c =
-        forAll (genEqualBuf) $ \(b, bi) -> bufEqual (insertI c bi) (insert c b)
+prop_insert2 c = forAll (genEqualBuf) $ \(b, bi) ->
+  insertI c bi <==> insert c b
+
+prop_delete :: BufferI -> Bool
+prop_delete bi = deleteI bi <==> delete (retrieve bi)
+
+prop_left :: BufferI -> Bool
+prop_left bi = leftI bi <==> left (retrieve bi)
+
+prop_right :: BufferI -> Bool
+prop_right bi = rightI bi <==> right (retrieve bi)
+
+prop_atLeft :: BufferI -> Bool
+prop_atLeft bi = atLeftI bi == atLeft (retrieve bi)
 
+prop_atRight :: BufferI -> Bool
+prop_atRight bi = atRightI bi == atRight (retrieve bi)
 
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