Re: Bit manipulation

[Lao Xiao Hai <laoxhai@ix.netcom.com>]

Robert Dewar wrote:

>
> Very nicely put! Indeed the point here is to learn as much
> about the problem as possible, so that the solution space can
> be explored in the most effective manner.

As you have pointed out many times Robert, Ada was never intended
to be a convenient language for writing programs.  It is more intended
for responsibly communicating the intended goal of the program with
the fewest errors.   Ease of writing gives way to ease of reading.

Ada is designed so most constructs are, by default, safe.   Therefore,
many convenient idioms common to less rigorous languages such as
automatic
type conversion, automatic promoting of a type,  no checking at all
on the mode or type of a parameter, etc., are avoided by Ada.  On
the other hand, it is quite possible to take a language in which the
default
for every construct is safe and relax the default to less safe.  It is
not
as easy when the default is unsafe (e.g., C and, to a somewhat lesser
extent,
C++) to override that and make the code more safe.

Bit manipulation is simply not that difficult in Ada.   And it does not
even
require overrding the default safety of the language, especially in Ada
95.
As has been noted in other postings, even Ada 83 provided
straightforward
solutions to this, albeit with the requirement that one abide by the
rules of
the language and make absolutely clear that what is being coded is
exactly what is intended.

Richard Riehle