Re: how to organize source code for a complete software? Thanks!

[Jinsong Zhao <jszhao@yeah.net>]

On 2011-10-10 1:16, stefan-lucks@see-the.signature wrote:
>> I am new to Ada, and I just have some experiences in using Fortran.
>>
>> When using Fortran, I generally put each subroutine or function in a separate
>> file, e.g., dot.for for dot product of two vectors. Then a main.for that call
>> the necessary subroutine or functions. It seems to be rational.
>>
>> When I using Ada, I don't know how to do. There are procedure, function,
>> package, package body, and so on (with different file extension, e.g., ada,
>> adb, ads, ...). And there is no main program.
>
> 1. Any parameterless procedure, which is not "local" inside another
>     function/procedure or inside a package, can be the main program.
>
> 2. As a rule of thumb for beginners: Put your auxiliary subprograms (in
>     Ada: a subprogram is either a function or a procedure) and the requited
>     type definition into packages. Write a single parameterless main
>     procedure as the "main" procedure, but give it a meaningful name
>     ("Solve_Linear_Equations" or "Delete_File" rather than "Main"). Put
>     that procedure into a file of its own.
>
> 2a. Note that a package consists of a specification and an implementation,
>      which are usually put into TWO different files (e.g., "name.ads" for
>      the spec and "name.adb" for the implementation body).
>
> 2b. When you are more advanced in programming in Ada, you may sometimes
>      want to compile "separate" subprograms without wrapping them into
>      packages.
>
> 3. Compile the main procedure (e.g., by calling "gnatmake" if you use the
>     gnat Ada compiler) -- your compiler will know which packages it needs
>     to compile.

Thank you very much. The above statements give me more information than 
what I get from the books available to me here. Now, I think I know how 
to layout my small program.

>
>> And, please, if you like, point me a small, complete open source software in
>> Ada (not a library or package). I should be compiled and run. I just hope to
>> learn how to start a software in Ada by example.
>
> Examples:
>    <http://rosettacode.org/wiki/Linear_congruential_generator#Ada>
>    <http://rosettacode.org/wiki/Ternary_logic#Ada>

It's a nice place for me. Thanks!

>
> The linear congruential example would consist of three files:
>    1. the specification "lcg.ads",
>    2. the implementation "lcg.adb", and
>    3. the main program "run_lcgs.adb".
> (These are the gnat/gcc naming conventions, look into your compiler
> documentation if you use another compiler.)
>
> As an easy exercise for the reader, try to figure out which three files
> the ternary logic example would consist of.
>
>
I think I can get the answer:
1. the specification "logic.ads",
2. the implementation "logic.adb", and
3. the main program "test_tri_logic.adb".

Thanks again for your informative reply and the example codes.

Regards,
Jinsong