(when (seq s) ...) reads to me as "do this as long as I can treat s sequentially". The following operations on s require it to be seqable, so it's like a runtime type check. not-empty is less direct, and feels like it's assuming that s is seqable.
Of course, not-empty is implemented with (when (seq)), so there's no REAL difference. At the end of the day, (when (seq)) is what people use.
Of course, not-empty is implemented with (when (seq)), so there's no REAL difference. At the end of the day, (when (seq)) is what people use.