Re: My bug or else regarding Visibility Rules

[Anh Vo <anhvofrcaus@gmail.com>]

On Monday, April 1, 2013 5:56:19 PM UTC-7, Randy Brukardt wrote:
> "Anh Vo" <anhvofrcaus@gmail.com> wrote in message news:89292c53-1d4e-48a7-b2ae-a10983ef4168@googlegroups.com... > On Thursday, March 28, 2013 3:03:13 PM UTC-7, Randy Brukardt wrote: >> "Adam Beneschan" <adam@irvine.com> wrote in >>> the >> > keyword PRIVATE >> > when that keyword is present; but if you take it out, the declaration >> > list >> > ends at "end Circular_Queue;". >> 
>>> Which is the long way to say that the expression of a public aspect has
>>> be made up only of public functions and objects. Otherwise, how would a 
>>> caller be able to figure out the meaning of a precondition that they are 
>>> required to meet? Clients can never be required to look in a private 
>>> part. 

>> Actually, this part only involves post-conditions (implementer), not 
>> preconditions (clients). 

>Clients need to know about postconditions as well, so that they know what >properties are guaranteed after a call. Typically, that will show that 
>some or all of a following precondition is going to be satisfied. Remember, >both of these matter to both sides of a call: A precondition is a requirement >on a caller and a promise to an implementation; a postcondition is a promise >to a caller and a requirement on an implementation. Randy.

I try to put as much as post-conditions that the language allows. On the other hand, I do not want to expose any thing that the clients can modify. In addition, taking away post-conditions involving Buffer, In_Index, and Out_Index objects by moving them into the body does degrade much implementation promise in this case.

A. Vo