Re: What is Delta??

[Keith Thompson <kst-u@mib.org>]

"Marc A. Criley" <mcNOSPAM@mckae.com> writes:
[...]
> An experienced Ada programmer knows what Ada code should look like, in
> terms of definitions, structures, and interactions.  A system that was
> dumped in my lap to port to a new OS version and compiler included the
> following:
>
> - A set of project-standard integer types were defined for 8, 16, and
> 32 bit items.  _Every_ other integer type was defined as a subtype of
> one of those.  Totally eliminated integer type conflicts--and checking.
> - In several packages record type definitions were defined using the C
> idiom for struct definitions, to the point of having the term "struct"
> as part of the type name, AND defining a subtype of the record for
> public use--ala the practice of having a typedef for struct
> definitions.
> - Handling message buffers by interfacing to the strcpy() function and
> using it to move bytes from memory buffer arrays to and from record
> components.
> - Used tasks where virtually all the work of the task was performed
> during task rendezvous, _including_ making entry calls on other
> tasks. This resulted in the world's most computationally expensive
> procedure calls.
>
> Clearly there were no experienced Ada hands on the project, and it showed.

Most of these sound horrendous, but one of them may not be.

C's strcpy() function copies a C-style string, terminated by a NUL
character.  If a NUL-terminated string format is imposed by some
external interface, then interfacing to strcpy() might be the most
reasonable approach.  Hand-written code to do the same thing, either
in C or in Ada, could easily be less efficient and more error-prone; a
C library's implementation of strcpy() is free to use system-specific
performance tricks and is likely to be thoroughly tested.

On the other hand, if the NUL-terminated string format *wasn't*
imposed by an external interface, imposing it on an Ada project seems
like a bad idea.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
San Diego Supercomputer Center             <*>  <http://users.sdsc.edu/~kst>
We must do something.  This is something.  Therefore, we must do this.