Task

Given a prompt and a list containing a number of strings of which one is to be selected, create a function that:

 prints a textual menu formatted as an index value followed by its corresponding string for each item in the list;
 prompts the user to enter a number;
 returns the string corresponding to the selected index number.


The function should reject input that is not an integer or is out of range by redisplaying the whole menu before asking again for a number. The function should return an empty string if called with an empty list.

For test purposes use the following four phrases in a list:

   fee fie
   huff and puff
   mirror mirror
   tick tock

Note

This task is fashioned after the action of the Bash select statement.

with ada.text_io,Ada.Strings.Unbounded; use  ada.text_io, Ada.Strings.Unbounded;
 
procedure menu is 
	type menu_strings is array (positive range <>) of Unbounded_String ;
	function "+" (s : string) return Unbounded_String is (To_Unbounded_String (s));
 
	function choice (m : menu_strings; prompt : string) return string is
	begin
		if m'length > 0 then
			loop 
				put_line (prompt);
				for i in m'range loop
					put_line (i'img &") " & To_String (m(i)));
				end loop;
				begin
					return To_String (m(positive'value (get_line)));
					exception when others => put_line ("Try again !");
				end;
			end loop;
		end if;
		return "";
	end choice;
 
begin
	put_line ("You chose " & 
		choice ((+"fee fie",+"huff and puff",+"mirror mirror",+"tick tock"),"Enter your choice "));
end menu;