Re: Building blocks (Was: Design By Contract)

[stt@houdini.camb.inmet.com (Tucker Taft)]

Robert A Duff (bobduff@world.std.com) wrote:

: ...
: By the way, speaking of negative logic, what do people think about
: negative logic in "if" statements?  I tend to try to reduce the number
: of "not"s in the code.  But other people tend to use some other
: heuristic, such as "do the normal case first" or "do unusual case
: first".  

FWIW, one of my heuristics is if one case is much shorter than the other,
do the shorter case first, as it is easier to see what is happening.
When you see something like:

     ... 200 lines
  else
     Do_Something;
  end if;

you can pretty easily lose track of what was the original condition
being tested.  Of course, another solution is to put a nice comment
after the "else" to say what is the condition governing the second case.
However, even if you put a comment on the else, I still find it clearer
to finish off the short case first, and then do the complicated one.

: - Bob

--
-Tucker Taft   stt@inmet.com   http://www.inmet.com/~stt/
Intermetrics, Inc.  Burlington, MA  USA