Re: short-circuit control forms (& 'long names are doom')

["DuckE" <nospam_steved94@home.com>]

There was an interesting thread on this subject back in 95 (search for short
circuit in the Google archives of comp.lang.ada).

I found Tucker Taft's comment particularly interesting:

": If both operands are
 : always evaluated, does that mean that whenever it is unnecessary to
 : evaluate the second operand, one should use the short-circuit operators
 : for efficiency?

 To avoid depending on the quality of your compiler's optimizer,
 I personally recommend using short-circuit operations by default,
 and only use "and" or "or" when it is *required* that both
 operands be evaluated.

 Of course, a clever optimizer can actually evaluate both
 operands even though a short circuit is specified, so long
 as there are no side-effects (including possibilities for
 exceptions).  For example, if A and B are boolean variables,
 then a compiler might decide it is more efficient to just
 "and" them together even when "and then" is specified,
 to avoid the extra conditional branches.

 Hence, if your compiler is clever, it doesn't matter what you
 do since it will un-do it if appropriate, and if your compiler is
 not clever, then using short-circuit by default probably produces
 somewhat better code quality on average.