Re: Beginner's questions

[Matthew Heaney <matthew_heaney@acm.org>]

marcoschmidt@geocities.com (Marco Schmidt) writes:

> >Those operations predefined for all modular types.  Were you using an
> >integer type?
> 
> Yes, but I want to use "and" and "or" for bitwise manipulation, not
> logical operations which evaluate to boolean. 

I don't understand this answer.

"and", "or", "xor", and "not" for a modular type are bitwise operators
that return a modular value, not Boolean.  

"and" and "or" aren't defined for (signed) integer types.

What kind of type type were you using?

Why isn't a modular type adequate?


> In Pascal, logical and bitwise operators have the same name (and /
> or), while there are different operators in C, C++ and Java (& and &&,
> | and ||). I need the & and | version.

Signed integer types in Ada95 have neither logical nor bitwise
operators.

Modular (unsigned) types in Ada95 have bitwise operators "and" and
"or".  They are not logical operators.

There is a way to define bitwise operators for a signed integer type,
but it's not going to be as efficient as using an unsigned type.