02

Signed-off-by: Skyball2000 <thomas3654william@gmail.com>

aufgaben/src/02/Date.elm

@@ -0,0 +1,203 @@
+module Date exposing (..)
+
+import String exposing (fromInt)
+
+type Weekday
+    = Mon
+    | Tue
+    | Wed
+    | Thu
+    | Fri
+    | Sat
+    | Sun
+
+
+type alias Day =
+    Int
+
+
+type alias Month =
+    Int
+
+
+type alias Year =
+    Int
+
+
+type alias Date =
+    ( Day, Month, Year )
+
+
+year : Date -> Year
+year ( _, _, y ) =
+    y
+
+
+month : Date -> Month
+month ( _, m, _ ) =
+    m
+
+
+day : Date -> Day
+day ( d, _, _ ) =
+    d
+
+
+lt : Date -> Date -> Bool
+lt ( d1, m1, y1 ) ( d2, m2, y2 ) =
+    (y1 < y2) || (y1 == y2 && m1 < m2) || (y1 == y2 && m1 == m2 && d1 < d2)
+
+
+eq : Date -> Date -> Bool
+eq ( d1, m1, y1 ) ( d2, m2, y2 ) =
+    y1 == y2 && m1 == m2 && d1 == d2
+
+
+gt : Date -> Date -> Bool
+gt ( d1, m1, y1 ) ( d2, m2, y2 ) =
+    (y1 > y2) || (y1 == y2 && m1 > m2) || (y1 == y2 && m1 == m2 && d1 > d2)
+
+
+toString : Date -> String
+toString ( d, m, y ) =
+    let
+        d0 =
+            if (d // 10) == 0 then
+                "0"
+
+            else
+                ""
+
+        m0 =
+            if (m // 10) == 0 then
+                "0"
+
+            else
+                ""
+    in
+    d0 ++ fromInt d ++ "." ++ m0 ++ fromInt m ++ "." ++ fromInt y
+
+
+next : Date -> Date
+next ( d, m, y ) =
+    case ( d, m, y ) of
+        ( 31, 12, _ ) ->
+            ( 1, 1, y + 1 )
+
+        ( 30, 11, _ ) ->
+            ( 1, 12, y )
+
+        ( 31, 10, _ ) ->
+            ( 1, 11, y )
+
+        ( 30, 9, _ ) ->
+            ( 1, 10, y )
+
+        ( 31, 8, _ ) ->
+            ( 1, 9, y )
+
+        ( 31, 7, _ ) ->
+            ( 1, 8, y )
+
+        ( 30, 6, _ ) ->
+            ( 1, 7, y )
+
+        ( 31, 5, _ ) ->
+            ( 1, 6, y )
+
+        ( 30, 4, _ ) ->
+            ( 1, 5, y )
+
+        ( 31, 3, _ ) ->
+            ( 1, 4, y )
+
+        ( 29, 2, _ ) ->
+            ( 1, 3, y )
+
+        ( 28, 2, _ ) ->
+            if leapyear y then
+                ( 29, 2, y )
+
+            else
+                ( 1, 3, y )
+
+        ( 31, 1, _ ) ->
+            ( 1, 2, y )
+
+        _ ->
+            ( d + 1, m, y )
+
+
+prev : Date -> Date
+prev ( d, m, y ) =
+    case ( d, m, y ) of
+        ( 1, 12, _ ) ->
+            ( 30, 11, y )
+
+        ( 1, 11, _ ) ->
+            ( 31, 10, y )
+
+        ( 1, 10, _ ) ->
+            ( 30, 9, y )
+
+        ( 1, 9, _ ) ->
+            ( 31, 8, y )
+
+        ( 1, 8, _ ) ->
+            ( 31, 7, y )
+
+        ( 1, 7, _ ) ->
+            ( 30, 6, y )
+
+        ( 1, 6, _ ) ->
+            ( 31, 5, y )
+
+        ( 1, 5, _ ) ->
+            ( 30, 4, y )
+
+        ( 1, 4, _ ) ->
+            ( 31, 3, y )
+
+        ( 1, 3, _ ) ->
+            if leapyear y then
+                ( 29, 2, y )
+
+            else
+                ( 28, 2, y )
+
+        ( 1, 2, _ ) ->
+            ( 31, 1, y )
+
+        ( 1, 1, _ ) ->
+            ( 31, 12, y - 1 )
+
+        _ ->
+            ( d - 1, m, y )
+
+
+leapyear : Year -> Bool
+leapyear y =
+    (modBy 4 y == 0) && ((modBy 100 y /= 0) || (modBy 400 y == 0))
+
+
+sub : Date -> Date -> Int
+sub d1 d2 =
+    subHelp 0 d1 d2
+
+
+
+{- um optimierbare End-Rekursion zu erreichen: Akkumulator als Argument -}
+
+
+subHelp : Int -> Date -> Date -> Int
+subHelp diff d1 d2 =
+    if gt d1 d2 then
+        subHelp (diff + 1) d1 (next d2)
+
+    else if lt d1 d2 then
+        subHelp (diff - 1) d1 (prev d2)
+
+    else
+        diff
+        
+        

aufgaben/tests/Pflichtuebung_01/DateTests.elm

@@ -88,55 +88,6 @@ testToString =
                 Expect.equal "02.06.2024" (toString (2, 6, 2024))
         ]
 
-testNext : Test
-testNext =
-    describe "next method test"
-        [test "next of 01.01.1970" <|
-            \() ->
-                Expect.equal (2, 1, 1970) (next (1, 1, 1970))
-        , test "next of 02.06.2024 " <|
-            \() ->
-                Expect.equal (3, 6, 2024) (next (2, 6, 2024))
-        , test "next of 31.12.2020" <|
-            \() ->
-                Expect.equal (1, 1, 2021) (next (31, 12, 2020))
-        -- leap year test
-        , test "next of 28.02.2020" <|
-            \() ->
-                Expect.equal (29, 2, 2020) (next (28, 2, 2020))
-        , test "next of 29.02.2020" <|
-            \() ->
-                Expect.equal (1, 3, 2020) (next (29, 2, 2020))
-        -- non-leap year test
-        , test "next of 28.02.2021" <|
-            \() ->
-                Expect.equal (1, 3, 2021) (next (28, 2, 2021))
-        ]
-
-testPrev : Test
-testPrev =
-    describe "prev method test"
-        [test "prev of 01.01.2000" <|
-            \() ->
-                Expect.equal (31, 12, 1999) (prev (1, 1, 2000))
-        , test "prev of 02.06.2024 " <|
-            \() ->
-                Expect.equal (1, 6, 2024) (prev (2, 6, 2024))
-        , test "prev of 1.12.2020" <|
-            \() ->
-                Expect.equal (30, 11, 2020) (prev (1, 12, 2020))
-        -- leap year test
-        , test "prev of 28.02.2020" <|
-            \() ->
-                Expect.equal (27, 2, 2020) (prev (28, 2, 2020))
-        , test "prev of 1.03.2020" <|
-            \() ->
-                Expect.equal (29, 2, 2020) (prev (1, 3, 2020))
-        -- non-leap year test
-        , test "prev of 1.03.2021" <|
-            \() ->
-                Expect.equal (28, 2, 2021) (prev (1, 3, 2021))
-        ]
 
 leapYearTest : Test
 leapYearTest =
@@ -155,36 +106,6 @@ leapYearTest =
                 Expect.equal False (leapyear 2022)
         ]
 
-subTest : Test
-subTest =
-    describe "sub test"
-        [test "sub 01.01.1970 01.01.1970" <|
-            \() ->
-                Expect.equal 0 (sub (1, 1, 1970) (1, 1, 1970))
-        , test "sub 01.01.1970 02.01.1970" <|
-            \() ->
-                Expect.equal -1 (sub (1, 1, 1970) (2, 1, 1970))
-        , test "sub 01.01.1970 01.02.1970" <|
-            \() ->
-                Expect.equal -31 (sub (1, 1, 1970) (1, 2, 1970))
-        , test "sub 01.01.1970 01.01.1971" <|
-            \() ->
-                Expect.equal -365 (sub (1, 1, 1970) (1, 1, 1971))
-        , test "sub 01.01.1970 01.01.1972" <|
-            \() ->
-                Expect.equal -730 (sub (1, 1, 1970) (1, 1, 1972))
-        , test "sub 01.01.1970 01.01.1974" <|
-            \() ->
-                Expect.equal -1461  (sub (1, 1, 1970) (1, 1, 1974))
-        -- explicit leap year 2020 test
-        , test "sub 27.02.2020 01.03.2020" <|
-            \() ->
-                Expect.equal -3 (sub (27, 2, 2020) (1, 3, 2020))
-        -- positive test
-        , test "sub 01.01.1970 01.01.1969" <|
-            \() ->
-                Expect.equal 365 (sub (1, 1, 1970) (1, 1, 1969))
-        ]
 
 
 ltTest : Test