|Is the value of iteration expressions always nil? I heartily recommend it to be at least a boolean, signifying whether the loop iterated at least once -- as it gives the very terse, readable idiom:|
(unless (each x mylist (...))
and the corresponding:
(if (each x mylist (...))
(Prior art of this idiom in RXML, the Roxen macro language, where you typically see it in templated database outpt with an <emit> loop body is followed by an <else> clause.)
For reference, I'm only just through the tutorial.