-- Simple.adb
-- Example of using a hash map in Ada. 

-- Here is a C++ map example that will be written in Ada, below...
-- #include <map>
-- #include <string>
-- int main( int argc, char* argv[] )
-- {
--  std::string keys[] = { "1", "2", "3" } ;
--  std::string vals[] = { "a", "b", "c" } ;
 
--  std::map< std::string, std::string > hash ;
 
--  for( int i = 0 ; i < 3 ; i++ )
--  {
--   hash[ keys[i] ] = vals[i] ;
--  }
-- } 

with Ada.Strings.Hash;
with Ada.Containers.Hashed_Maps;
with Ada.Text_Io;
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
 
procedure Simple is
   function Equivalent_Key (Left, Right : Unbounded_String) return Boolean is
   begin
      return Left = Right;
   end Equivalent_Key;
 
   function Hash_Func(Key : Unbounded_String) return Ada.Containers.Hash_Type is
   begin
      return Ada.Strings.Hash(To_String(Key));
   end Hash_Func;
 
   package My_Hash is new Ada.Containers.Hashed_Maps(
	Key_Type => Unbounded_String,Element_Type => Unbounded_String,
			Hash => Hash_Func,Equivalent_Keys => Equivalent_Key);
 
   type String_Array is array(Positive range <>) of Unbounded_String;
 
   Hash : My_Hash.Map;
   Key_List : String_Array := (To_Unbounded_String("foo"), 
			To_Unbounded_String("bar"), To_Unbounded_String("val"));
 
   Element_List : String_Array := (To_Unbounded_String("little"), 
		    To_Unbounded_String("miss"), To_Unbounded_String("muffet"));
 
begin
   for I in Key_List'range loop
      Hash.Insert(Key => (Key_List(I)), New_Item => (Element_List(I)));
   end loop;
   for I in Key_List'range loop
      Ada.Text_Io.Put_Line(To_String(Key_List(I)) & " => " &
					To_String(Hash.Element(Key_List(I))));
   end loop;
 
end Simple;