Re: Question for the folks who designed Ada95

[Robert Dewar <robert_dewar@my-dejanews.com>]

In article <7g4mic$1sr0@news2.newsguy.com>,
  Samuel Mize <smize@imagin.net> wrote:
> If you have to worry about line-by-line efficiency, you
> really have to cuddle up to your compiler and learn a lot
> about it.

The issue here (as described in detail in the AARM) has
nothing whatsoever to do with compiler or runtime
efficiency, it is purely a semantic concern). Here is
the full quote from the AARM if people do not have it
at hand:

<<AARM B.2 (9-a)>>

9.a   Reason:  We considered making shifting and rotating
be primitive operations of all modular types.  However, it
is a design principle of Ada that all predefined operations
should be operators (not functions named by identifiers).
(Note that an early version of Ada had "abs" as an
identifier, but it was changed to a reserved word operator
before standardization of Ada 83.)  This is important
because the implicit declarations would hide
non-overloadable declarations with the same name,
whereas operators are always overloadable.

Therefore, we would have had to make shift and rotate into
reserved words, which would have been upward incompatible,
or else invent new operator symbols, which seemed like too
much mechanism.

<<end of quote>>

This seems quite straightforward and convincing!

-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/       Search, Read, Discuss, or Start Your Own