Re: Advice on selling Ada to a C shop

[anon@att.net]

In <9b5af9c0-43a3-4a9d-9a03-5b6c794f611e@e5g2000yqn.googlegroups.com>, Maciej Sobczak <see.my.homepage@gmail.com> writes:
>On 23 Cze, 21:57, "Peter C. Chapin" <pcc482...@gmail.com> wrote:
>
>> My understanding is that Ada is primarily a "systems" programming language. It
>> supports embedded programming, real time programming, and other "low level"
>> applications. People writing such programs are not particularly concerned
>> about GUI packages. Well... I can't speak for everyone, but I'm using Ada in
>> an embedded application and I'm certainly not worried about the lack of GUI
>> support.
>
>The reason for why GUI is not (and will not be) in the Ada standard
>library is the same as in C++ - there are too many ways to do it and
>the cost of prototyping is too high to attract attention of
>individuals who are usually *volunteers* in standardization efforts.
>Especially when the already acceptable solution is to live with
>existing third-party library or libraries.
>
>> I wasn't involved in the discussion that lead to the decision to include
>> conditional expressions in Ada
>
>Again similarity to C++ - conditional expressions are *essential* for
>initializing constants. Without them programmers are forced to either
>use modifiable variables where constants would be more natural (this
>is unsafe) or to write local or helper functions, which destroys the
>locality of reference for code entities (this is less readable ->
>unsafe).
>
>I'm glad that Ada is going to adopt them.
>
>--
>Maciej Sobczak * http://www.inspirel.com
>
>YAMI4 - Messaging Solution for Distributed Systems
>http://www.inspirel.com/yami4

Now, except for "GNAT.Sockets.*" and the outdate "pragma No_Rum_Time"
GNAT has side-step the following design concept.

    "The language must also be "complete" in the sense of the user being 
    able to write all usual programs without having to resort to assembly 
    language or local extensions. It had to have real-time capability and 
    it had to be set up to produce programs for the bare machine in a 
    missile, without support of an operating system. It also was required 
    to support large Command and Control systems, so it had to have a 
    file input/output system, however messy that might be."


This paragraph suggest that they should be packages under Ada.* or 
System.* that would control the hardware such as the Serial (both UART 
and USB), parallel ports. And all connection types (bus, serial, usb, 
and parallel, etc) for the keyboard and mouse devices.  Plus, it should 
have routine to control network cards and other standard I/O, such as 
direct video control and disk while bypassing the OS.  But no Ada 83 
system every used the RM defined Low_Level_IO package. And in Ada 95 
and Ada 2005 there is no packages that are defined in the RM that 
control any group of hardware directly, bare machine or not. The Ada 
package mostly just linked to a precompiled library (aka local 
extensions) that connected to the OS. So, where are these packages? 


Note:  Allowing Ada to be written without using "Local Extension" can 
       mean that Ada needs a "Universal Windows/Graphics" package 
       groups that in one version links to the OS, as well as 
       having another directly control the graphics of a group of 
       common GPU cards. Where is the package or packages, without 
       the programmer using assembly language or the Machine_Code 
       package?


Plus, the file system in some case needs to be self-contained without 
the OS. So where are the System.File_System.* packages like fat, ext2, 
ext3, etc. ? Or may be a generic package for creating file systems.