On Fri, Jan 11, 2013 at 10:34 AM,  <sto.mar / web.de> wrote:
> A student (and maybe not only a student) might happily refactor
>
>   if cond1 and cond2
>     ...
>   end
>
> to
>
>   condition = cond1 and cond2
>   if condition
>     ...
>   end
>
> without ever noticing that this would break the logic of the code.

This is a *very* good point -- one which I had not considered. Even if
*I* understand how they work, the next person (or n-th person) looking
at my code might not. Now I really do understand the choice in the
style guide. I personally have not used and/or in if/unless
statements; I've only used them for control. But now I'm finding using
if/unless to manage the control much clearer, and using and/or in that
way does begin to seem more like a side-effect. I'm joining the ban
the and crowd.