rangecheck.lisp

(defun rangecheck (rc)
  (lambda (actual)
    (let* ((comparator (intern (property rc "Comparator") #.*package*))
	   (unit (find-def (kid-like 'measurementunitref :in rc)))
	   (test (case comparator
		  (LT '<)
		  (LE '<=)
		  (GT '>)
		  (GE '>=)
		  (EQ '=)
		  (IN 'member)
		  (NOTIN (complement #'member))))
	   (vals (if (member comparator '(IN NOTIN))
		     (mapcar (lambda (val)
			       (read-from-string (value-of val)))
			     (kids-like 'checkvalue :in rc))
		     (read-from-string (value-of (kid-like 'checkvalue :in rc)))))

      (values
       (funcall test actual vals)
       (string-trim +whitespace+ (value-of (kid-like 'errormessage :in rc)))))))