collect it
and collect it)
'(a z b z c z d z))))
+
+(let ((ht (make-hash-table)))
+ (setf (gethash 1 ht) 3)
+ (setf (gethash 7 ht) 15)
+ (assert (= (loop for v fixnum being each hash-key in ht sum v) 8))
+ (assert (= (loop for v fixnum being each hash-value in ht sum v) 18))
+ (assert (raises-error? (loop for v float being each hash-value in ht sum v)
+ type-error)))