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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: renaming Interfaces.Java.Ada_To_Java_String to the + operator
Date: 1998/01/11
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Chris said

<<I think all those would be fine. I was just saying it was nice that
someone had offered something to allow an approximation of the varargs
C functions rather than the previous approach of saying "sorry, Ada
doesn't do varargs so you will have to use the non-varargs versions
instead" which wouldn't have fitted in with my accustomed style of
Motif programming.
>>

Well I am surprised that anyone would have taken this "previous" approach.
Certainly the possibility of using array aggregates in this way is the
reason that you don't need varargs type support in a language like Ada
(this is not a new idea, this usage is completely familiar from Algol-68).

So this is not some kind of "neat discovered trick" in the language, it is
an important part of the intended design!

Regarding the quadratic behavior, and your mention of efficiency in Ada 83,
in fact if you think about

   a & b & c & d

the natural implementation will definitely be quadratic, since this really
means

  ((a & b) & c) & d)

and in the general case, e.g. with user defined concatenation, must be
done in three separate operations. A compiler can specially recognize
this case, but it is not a trivial optimization (I just put it into GNAT,
and it took a full day of work to get it right).