the section on loops, in particular, really captured a small but ubiquitous frustration in every language I've used. we really should be able to say "this is th

the section on loops, in particular, really captured a small but ubiquitous frustration in every language I've used. we really should be able to say "this is the first iteration", " this is the last iteration" (though that one might not always be possible) and "did the loop run at all?" without getting into index comparisons or manually setting and modifying flags.