(define-method (set-attribute (ih <IHandle>) (key <keyword>) (value <string>))
  ((setter attributes) ih (alist-cons key value (attributes ih)))
  ((foreign-lambda void "IupSetAttribute" c-pointer c-string c-string) (ptr ih) (string-upcase (keyword->string key)) value))
(define-method (get-attribute (ih <IHandle>) (key <keyword>))
  ((foreign-lambda c-string "IupGetAttribute" c-pointer c-string) (ptr ih) (string-upcase (keyword->string key))))