1 files changed, 4 insertions, 4 deletions

diff --git a/AufgabeFFP7.hs b/AufgabeFFP7.hs
index c9454a5..091cb49 100644
--- a/AufgabeFFP7.hs
+++ b/AufgabeFFP7.hs
@@ -13,7 +13,7 @@ empty = (0, "")
 
 -- insert character before cursor
 insert :: Char -> Buffer -> Buffer
-insert c (cur, buf) = (cur, buf1 ++ [c] ++ buf2)
+insert c (cur, buf) = (min (length buf + 1) (max (cur - 1) 0), buf1 ++ [c] ++ buf2)
   where
     (buf1, buf2) = splitAt cur buf
 
@@ -21,7 +21,7 @@ insert c (cur, buf) = (cur, buf1 ++ [c] ++ buf2)
 delete :: Buffer -> Buffer
 delete (cur, buf)
   | buf2 == [] = (min cur (length buf1), buf1)
-  | cur < 0 = (cur, buf)
+  | cur < 0 = (0, buf)
   | otherwise = (cur, buf1 ++ tail buf2)
   where
     (buf1, buf2) = splitAt cur buf
@@ -36,11 +36,11 @@ right (cur, buf) = (max 0 (min (cur + 1) (length buf)), buf)
 
 -- is cursor at left end?
 atLeft :: Buffer -> Bool
-atLeft (cur, buf) = cur == 0
+atLeft (cur, buf) = cur <= 0
 
 -- is cursor at right end?
 atRight :: Buffer -> Bool
-atRight (cur, buf) = cur == length buf
+atRight (cur, buf) = cur >= length buf
 
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