Re: Need some help in Ada

[Robert A Duff <bobduff@TheWorld.com>]

danifreecs@gmail.com writes:

> Thank you for the reply! So it should be Components: String(1..Size)?

Yes.

> then i wrote this:
> function Create(Str : String) return J_String is
> 	Jstr: J_String(Str'Length);
> 	begin	
> 		if (Str'Length = 0) then
> 			Jstr.Components := "";
> 		else
> 			Jstr.Components := Str;
> 		end if;
> 	return Jstr;
> 	end Create;

That looks like it will work, although you should try to format it in a
more standard way.  But it's more complicated than it needs to be.  You
don't need to special case the empty string.  A single return statement,
returning an aggregate, will work:

    return (Size => ..., Components => ...);

I think you can figure out what the "..." parts should be.

> when i try to use it like: jstr1: J_String(4) := Create("doge");
> i get this error "expected private type ada.text_io.file_type" which
> i can't really understand.

That's a visibility problem.  Your Create is not directly visible,
but the Create in Ada.Text_IO is, so the compiler thinks you want
the latter.  You need a "use" clause, or you need to say
J_String_Pkg.Create(...).

By the way, you don't want that "4":

    jstr1: J_String := Create("doge");

or maybe:

    jstr1: constant J_String := Create("doge");

Let the program figure out the length.  You shouldn't have to count the
number of characters in "doge".

- Bob