new files

Task/Search-a-list/Ada/search-a-list.ada

@@ -0,0 +1,42 @@
+with Ada.Strings.Unbounded;  use Ada.Strings.Unbounded;
+with Ada.Text_IO;            use Ada.Text_IO;
+
+procedure Test_List_Index is
+   Not_In : exception;
+
+   type List is array (Positive range <>) of Unbounded_String;
+
+   function Index (Haystack : List; Needle : String) return Positive is
+   begin
+      for Index in Haystack'Range loop
+         if Haystack (Index) = Needle then
+            return Index;
+         end if;
+      end loop;
+      raise Not_In;
+   end Index;
+
+      -- Functions to create lists
+   function "+" (X, Y : String) return List is
+   begin
+      return (1 => To_Unbounded_String (X), 2 => To_Unbounded_String (Y));
+   end "+";
+
+   function "+" (X : List; Y : String) return List is
+   begin
+      return X & (1 => To_Unbounded_String (Y));
+   end "+";
+
+   Haystack : List := "Zig"+"Zag"+"Wally"+"Ronald"+"Bush"+"Krusty"+"Charlie"+"Bush"+"Bozo";
+
+   procedure Check (Needle : String) is
+   begin
+      Put (Needle);
+      Put_Line ("at" & Positive'Image (Index (Haystack, Needle)));
+   exception
+      when Not_In => Put_Line (" is not in");
+   end Check;
+begin
+   Check ("Washington");
+   Check ("Bush");
+end Test_List_Index;