Re: Ada95 Strengths/Weaknesses.

[falis@ma.aonix.com (Ed Falis)]

On 27 Sep 1999 19:48:02 -0400, Hyman Rosen <hymie@prolifics.com> wrote:


> Aside from the verbosity of the Ada code (which is apparent even though
> the C++ equivalents aren't written idiomatically), notice that in the
> output code, it is necessary to repeat the types of the things being
> output, even though the ompiler already knows it!

Not necessary.  MDC is using a more verbose idiom than necessary to 
do the job.

> 
> By the way, here's the C++ for your unimplemented third case -

Not quite the same thing as he did.  Below is Ada code that does what
your C++ does. Let's not confuse style and substance (yes, it's still more
verbose, partly because of multi-line routine definitions and your not using
a header file).

- Ed

package Saver is
    type Save_Stuff (Name_Length: Natural) is private;
    
    function New_Save_Stuff (Str: String; Val: Integer) return Save_Stuff;
    
    procedure Put (S: in out Save_Stuff; X: Integer);
    
    function Get (S: Save_Stuff) return Integer;
private
    type Save_Stuff (Name_Length: Natural) is record
        Name: String (1..Name_Length);
        Save: Integer;
    end record;
end Saver;

package body Saver is

    -- This is used because the C++ default access is private, right?
    function New_Save_Stuff (Str: String; Val: Integer) return Save_Stuff is
    begin
        return Save_Stuff'(Str'Length, Str, Val);
    end;
    
    
    procedure Put (S: in out Save_Stuff; X: Integer)is
    begin
        S.Save := X;
    end;
    
    
    function Get (S: Save_Stuff) return Integer is
    begin
        return S.Save;
    end;
end Saver;

with Saver; use Saver;
with Ada.Text_Io, Ada.Integer_Text_Io;
use Ada.Text_Io, Ada.Integer_Text_Io;
procedure Main is
    My_Obj: Save_Stuff := New_Save_Stuff ("My Object", 55);
    Your_Obj: Save_Stuff := New_Save_Stuff ("Your Object", 55);
begin
    Put (My_Obj, 23);
    Put ("The value of my object is "); Put (Get (My_Obj));
    New_Line;
    
    Put (Your_Obj, 46);
    Put ("The value of your object is "); Put (Get (Your_Obj));
    New_Line;
end Main;

    
        
    
> 
> #include <iostream>
> #include <string>
> 
> using namespace std;
> 
> class SaveStuff
> {
> 	string name;
> 	int save;
> public:
> 	Save_Stuff(string n = string(), int s = 0) : name(n), save(s) { }
> 	void put(int x) { save = x; }
> 	int get() const { return save; }
> };
> 
> int main()
> {
> 	SaveStuff my_obj("My Object", 55);
> 	SaveStuff your_obj("Your Object", 55);
> 
> 	my_obj.put(23);
> 	cout << "The value of my object is " << my_obj.get() << endl;
> 
> 	your_obj.put(46);
> 	cout << "The value of your object is " << your_obj.get() << endl;
> }
> 
>