Re: How do you bitwise operations in Ada '83 and '95

["jimmaureenrogers@worldnet.att.net" <jimmaureenrogers@worldnet.att.net>]

Jeffrey R. Carter wrote:
> jimmaureenrogers@worldnet.att.net wrote:
> >
> > The following example shows bit-wise operations using a
> > packed array of boolean. The small program computes prime
> > number using a sieve of Erastosthenese. The array flagging
> > found values is implemented as a packed array of boolean.
>
> No, it doesn't. It simply shows normal array operations on a packed
> array of Boolean.

I guess that depends upon your definition of bit-wise operations.
Very few languages support direct indexing of an array of bits.
The equivalent access operations are a lot of nasty bit masking
an bit shifting operations.

The fact is, with an Ada packed array of boolean you can
achieve the same results while maintaining the high level
abstraction of an array.

Related to bit-wise operations are record representation
clauses. Ada differs from C and C++ in ability to control
the layout of compound types. Ada provides much finer
grained control, allowing one to map types to specific
bits, controlling all padding operations, and even allowing
fields to cross word boundaries.

All these features are part of control of and access to
data at the bit level. Ada's abilities in these areas are
really quite impressive.

Jim Rogers