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From: Robert A Duff <bobduff@shell01.TheWorld.com>
Newsgroups: comp.lang.ada
Subject: Re: and then... (a curiosity)
Date: Wed, 03 Sep 2008 01:56:32 -0400
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Date: 2008-09-03T01:56:32-04:00
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Santiago Urue�a <suruena@gmail.com> writes:

> suggest using plain "and" / "or" operators when just boolean flags are
> involved because it is usually faster to evaluate all the variables
> than using lazy evaluation.

I don't buy that argument, because the semantics of "A and B and C"
are identical to the semantics of "A and then B and then C" (when A, B,
and C are Boolean variables), so the compiler is free to generate
identical code for both.  If efficiency is important in this case,
the compiler should be trained to make it efficient, and the programmer
shouldn't have to worry about it.

Your point for (non-inlined) function calls is valid, though -- the
compiler can't be expected to know what's in the function in general.

- Bob