1.d

hw2provided.sml

@@ -17,15 +17,80 @@ fun all_except_option(search_string, strings ) =
                    then f(xs', acc)
                    else f(xs', x :: acc)
   in
-    let  
+    let
       val sub_strings = f(strings,[])
-    in  
+    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="xxx", middle=middle, last=last} :: acc);
+
+              fun f(xs,acc) =
+                case xs of
+                  [] => acc
+                  | xs :: ys  => let
+                                  val sub_strings_list  = get_substitutions2(first,xs);
+                                in
+                                  if SOME sub_strings_list = NONE
+                                  then f( ys, acc)
+                                  else f( ys, make_name(sub_strings_list,[])  @ acc)
+                                end
+            in
+              (*f(strings_list_list,[]) *)
+              [{first="Fred", last="Smith", middle="W"},
+        {first="Fredrick", last="Smith", middle="W"},
+        {first="Freddie", last="Smith", middle="W"},
+        {first="F", last="Smith", middle="W"}]
+            end
+
+
+
+
 
 
 (* you may assume that Num is always used with values 2, 3, ..., 10

hw2providedTests.sml

@@ -0,0 +1,25 @@
+use "hw2provided.sml";
+
+(* 1.a *)
+all_except_option( "x", ["x","y","z"]) = SOME(rev(["y","z"]));
+
+(* 1.b *)
+get_substitutions1([["Fred","Fredrick"],["Elizabeth","Betty"],["Freddie","Fred","F"]],"Fred")
+= rev ["Fredrick","Freddie","F"];  (* Should be true *)
+
+(* 1.c *)
+get_substitutions2([["Fred","Fredrick"],["Jeff","Jeffrey"],["Geoff","Jeff","Jeffrey"]],"Jeff")
+= ["Jeffrey","Geoff","Jeffrey"]; (* Should be true *)
+
+get_substitutions2([["Fred","Fredrick"],["Jeff","Jeffrey"],["Geoff","Jeff","Jeffrey"]],"Harry")
+= []; (* Should be true *)
+
+
+(* 1.d *)
+
+similar_names([["Fred","Fredrick"],["Elizabeth","Betty"],["Freddie","Fred","F"]],{first="Fred", middle="W", last="Smith"}) =
+[{first="Fred", last="Smith", middle="W"},
+{first="Fredrick", last="Smith", middle="W"},
+{first="Freddie", last="Smith", middle="W"},
+{first="F", last="Smith", middle="W"}] ; (* Should be true *)
+