Re: feedback asked on dab-decoder software in Ada

[jan van katwijk <j.vankatwijk@gmail.com>]

Op donderdag 15 september 2016 11:00:10 UTC+2 schreef Jacob Sparre Andersen:
> Jan van Katwijk wrote:
> 
> > This summer I wanted to learn Ada (again, after a period of well over
> > 20 years) and I made a reimplementation of the DAB software in Ada.
> 
> Sounds like an ambitious project.
> 
> > I would like to get some feedback on the use of the Ada language.
> 
> Some comments and questions:
> 
> + It would make it easier to get contributions from other Ada
>   developers, if you switched source style to something closer
>   to what is suggested by the Ada Quality and Style Guide [1].
> 
> + Why do you put the package specifications in a separate directory?
> 
> + You might benefit from running your compiler with more warnings
>   enabled.
> 
> + A package body doesn't have to "with" itself.
> 
> + There are no guarantees that "Integer" in Ada is the same as "int" in
>   C.  If you need a C "int", you should use "Interfaces.C.int".
> 
> + Are you sure you need as many access types as you declare?  (It looks
>   - understandably - a bit like you are writing C in Ada.)
> 
> + It looks like you aren't getting as much out of the type system as you
>   could.  (A length should probably not be able to contain negative
>   values. - Just to take a single example.)
> 
> > Any feedback and suggestions for improvement (it definitely runs
> > slower than the C++ version) is welcome
> 
> I would suggest that you postpone the performance improvements a bit,
> and focus on getting more out of Ada.
> 
> Greetings,
> 
> Jacob
> 
> [1] http://www.adaic.org/resources/add_content/docs/95style/html/cover.html
> -- 
> "For there are only two reasons why war is made against a
>  republic: The one, to become lord over her: the other, the
>  fear of being occupied by her."       -- Nicolo Machiavelli

Thanks for the comments. In the meantime I tried to apply some guideline rules, and the gnat compiler does not complain anymore on the layout.
Wrt identifiers: I am not impressed very much by the guidelines, to me Is_Running is not better readable than isRunning, Has_Property not than hasProperty.

First of all: the ada implementation of DAB is derived from the existing C++ implementation, all algorithms were extensively tried and tested in C++, so the complexity was more on using C libraries (I use several C libraries), some of them with callbacks. That all went pretty smooth, however, handling the GUI turned out to be more difficult than hndling the much more complex GUI in C++ (GtkAda vs Qt) 

The code and coding style is obviously influenced by having programmed in C++ for the last 10 years. Wrt access types, I really have to look at it, most likely it follows from the C++ background.

Anyway, thanks for the advices, I'll continue to make it more "Ada-style"

jan