Done with assignment 2

hw2provided.sml

@@ -145,3 +145,30 @@ fun remove_card( deck , pick , ex) =
       else getOpt(cards_left,[])
    end
 
+fun all_same_color( cards) =
+        case cards of
+          [] => true
+          | x::[] => true
+          | first :: (second :: rest) => (card_color(first) = card_color(second) andalso all_same_color(second :: rest))
+
+
+
+
+fun sum_cards( cards) =
+    let fun f(xs,acc) =
+        case xs of
+          [] => acc
+          | xs :: ys => f(ys, card_value(xs) + acc)
+    in
+      f(cards,0)
+    end
+
+
+fun score(cards,goal) =
+  let 
+     val sum = sum_cards(cards);
+   in 
+      if sum <= goal
+      then goal - sum
+      else sum - goal
+    end

hw2provided.txt

@@ -0,0 +1,174 @@
+(* Dan Grossman, Coursera PL, HW2 Provided Code *)
+
+(* if you use this function to compare two strings (returns true if the same
+   string), then you avoid several of the functions in problem 1 having
+   polymorphic types that may be confusing *)
+fun same_string(s1 : string, s2 : string) =
+    s1 = s2
+
+(* put your solutions for problem 1 here *)
+
+
+fun all_except_option(search_string, strings ) =
+ let fun f (xs,acc) =
+    case xs of
+     [] => acc
+     | x :: xs' => if same_string(search_string,x)
+                   then f(xs', acc)
+                   else f(xs', x :: acc)
+  in
+    let
+      val sub_strings = f(strings,[])
+    in
+     if length(sub_strings) = length(strings)
+     then NONE
+     else  SOME sub_strings
+     end
+  end
+
+   fun get_substitutions1( strings_list_list, search_string) =
+    let fun f(xs,acc) =
+        case xs of
+          [] => acc
+          | xs :: ys => let
+                          val sub_strings_list = all_except_option(search_string,xs);
+                        in
+                          if sub_strings_list = NONE
+                          then f( ys, acc)
+                          else f( ys, getOpt(sub_strings_list,[])  @ acc)
+                        end
+    in
+      f(strings_list_list,[])
+    end
+
+
+
+
+  fun get_substitutions2( strings_list_list, search_string) =
+    let fun f(xs,acc) =
+        case xs of
+          [] => acc
+          | xs :: ys => let
+                          val sub_strings_list = all_except_option(search_string,xs);
+                        in
+                          if sub_strings_list = NONE
+                          then f( ys, acc)
+                          else f( ys, getOpt(sub_strings_list,[])  @ acc)
+                        end
+    in
+      f(strings_list_list,[])
+    end
+
+
+ fun similar_names( strings_list_list, {first,middle,last}) =
+            let
+              fun make_name(xs,acc) =
+                  case xs of
+                  [] => acc
+                  | x :: xs' =>   make_name(xs',{first=x, middle=middle, last=last} :: acc);
+              fun f(xs,acc) =
+                case xs of
+                  [] => acc
+                  | xs  :: ys  => let
+                                    val sub_strings_list  = get_substitutions2(xs,first);
+                                  in
+                                    if SOME sub_strings_list = NONE
+                                    then f( ys, acc)
+                                    else f( ys, acc @ make_name(sub_strings_list,[]))
+                                  end
+            in
+              f([strings_list_list],[{first=first,middle=middle,last=last}])
+            end
+
+
+
+
+(* you may assume that Num is always used with values 2, 3, ..., 10
+   though it will not really come up *)
+datatype suit = Clubs | Diamonds | Hearts | Spades
+datatype rank = Jack | Queen | King | Ace | Num of int
+type card = suit * rank
+
+datatype color = Red | Black
+datatype move = Discard of card | Draw
+
+exception IllegalMove
+
+(* put your solutions for problem 2 here *)
+
+exception NoCardsFound
+
+fun card_color(card) =
+  case card of
+    (Spades   , _) => Black
+   |(Clubs    , _) => Black
+   |(Diamonds , _) => Red
+   |(Hearts   , _) => Red
+
+fun card_value(card) =
+  case card of
+    (_ , Jack)  => 10
+   |(_ , Queen) => 10
+   |(_ , King)  => 10
+   |(_ , Ace)   => 11
+   |(_ , Num  x)  => x
+
+
+fun same(c1 , c2 ) =
+    c1 = c2
+
+
+fun all_cards_except_option(pick, cards ) =
+ let fun f (xs,acc) =
+    case xs of
+     [] => acc
+     | x :: xs' => if same(pick,x)
+                   then f(xs', acc)
+                   else f(xs', x :: acc)
+  in
+    let
+      val cards_left = f(cards,[])
+    in
+     if length(cards_left) = length(cards)
+     then  NONE
+     else  SOME cards_left
+     end
+  end
+
+
+fun remove_card( deck , pick , ex) =
+  let
+     val cards_left = all_cards_except_option(pick,deck)
+    in
+      if cards_left = NONE
+      then raise ex
+      else getOpt(cards_left,[])
+   end
+
+fun all_same_color( cards) =
+        case cards of
+          [] => true
+          | x::[] => true
+          | first :: (second :: rest) => (card_color(first) = card_color(second) andalso all_same_color(second :: rest))
+
+
+
+
+fun sum_cards( cards) =
+    let fun f(xs,acc) =
+        case xs of
+          [] => acc
+          | xs :: ys => f(ys, card_value(xs) + acc)
+    in
+      f(cards,0)
+    end
+
+
+fun score(cards,goal) =
+  let 
+     val sum = sum_cards(cards);
+   in 
+      if sum <= goal
+      then goal - sum
+      else sum - goal
+    end

hw2providedTests.sml

@@ -44,9 +44,29 @@ card_value(Diamonds,Queen) = 10;
 card_value(Hearts,King) = 10;
 
 (* 2.c *)
-remove_card([(Spades,Ace),(Spades,Jack)],(Clubs,Queen),NoCardsFound) =  NoCardsFound;
-remove_card([(Spades,Ace),(Spades,Jack)],(Spades,Queen),NoCardsFound) =  NoCardsFound;
-remove_card([(Spades,Ace),(Spades,Jack)],(Spades,Ace),NoCardsFound) = [(Spades,Jack)];
+val c1 = (Spades,Ace);
+val c2 = (Spades,Jack);
+val c3 = (Clubs,Queen);
+val c4 = (Spades,Queen);
 
+val y = remove_card([c1,c2],c3,NoCardsFound)  handle NoCardsFound  => [c1,c2];
+val x = remove_card([c1,c2],c4,NoCardsFound)  handle NoCardsFound  => [c1,c2];
 
+remove_card([c1,c2],c1,NoCardsFound) = [c2];
+
+(* 2.d *)
+
+all_same_color([(Spades,Ace),(Clubs,Ace),(Clubs,King)]) = true;
+all_same_color([(Spades,Ace),(Diamonds,Ace)]) = false;
+
+
+(* 2.e *)
+
+sum_cards([c1,c2]) = 21;
+sum_cards([(Spades,Num 9),(Clubs,Num 3),(Spades,King)]) = 22;
+
+(* 2.f *)
+
+score([c1,c2],5) = 21 - 5;
+score([(Spades,Num 9),(Clubs,Num 3),(Spades,King)],25) = 25 - 22;