Well, it was a misinterpretation. I guess when I read the line from perlsyn

The only kind of simple statement is an expression evaluated for its side effects.

I twisted it around to "a statement is an expression".

But I think I've got it now: EXPR1 while EXPR2 is a statement, and using || versus or depends on (and affects) what else is in EXPR2, not the full statement.

On the other hand, "do_something() or die" is an expression (which, being evaluated for its side-effects, is also a statement). If the do_something returns 0 or '', the die will be evaluated as part of the expression, not as a statement modifier.

Have I got it right now?

I guess I tripped on the outward similarity of the two, and thought of or as a statement modifier like while and if.

P.S. merlyn, I don't think this is what you wanted to illustrate in your note, but I did learn something valuable. Thanks!