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From: 18k11tm001@sneakemail.com (Russ)
Newsgroups: comp.lang.ada
Subject: Re: Ideas for Ada 200X
Date: 30 May 2003 21:30:54 -0700
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Robert A Duff <bobduff@shell01.TheWorld.com> wrote in message news:<wcc65ns9pix.fsf@shell01.TheWorld.com>...
> 18k11tm001@sneakemail.com (Russ) writes:
> 
> > And let's not forget that +=, -=, etc. also allow for more efficient
> > in-place vector/matrix operations because they avoid the need for a
> > temporary. If you don't understand this, that's OK, but please don't
> > argue with me because you will be wrong.
> 
> I can't let *that* slip by...  ;-)
> 
> Calling the procedure += instead of, say, Add_Matrix will not make it
> faster!  The += notation is purely syntactic sugar, and has nothing
> to do with efficiency.
> 
> - Bob

OK, I guess I wasn't clear enough. I meant that A += B is (if properly
implemented) much more efficient than A := A + B. For anyone who
doesn't understand why, it is because the latter requires the
construction of a temporary to hold the sum, then a copy of the sum
back over to A.

Yes, you can always define Add_Matrix(A,B), or even
Add_Matrix(Into=>A,From=>B), but if that appeals to you ... oh, forget
about it.

Yes, += is syntactic sugar. So is +, for that matter. After all, you
can always write a function called Plus(A,B). Do you therefore
recommend we dump +?

Come to think of it, programming languages in general really boil down
to "syntactic sugar," don't they. We could just use machine language.