Ar an seachtú lá de mí na Nollaig, scríobh Julian Bradfield: The latter. The particular incantation you want here is: (eval-when-compile code to construct regexp ) This is equivalent to a progn call when interpreted, but at compilation the value the code returned is used as a byte code constant, just as a literal string would be. A related form is #'load-time-value, which is also equivalent to #'progn when interpreted, but is called once on load of a file and its return value saved to avoid recalculation each time a function is called. In general, the Common Lisp people will say that if you’re calling #'eval from normal user code, you’re probably missing some technique that would be less expensive and better optimised. This is mostly the case in Emacs Lisp, too. -- ‘Iodine deficiency was endemic in parts of the UK until, through what has been described as “an unplanned and accidental public health triumph”, iodine was added to cattle feed to improve milk production in the 1930s.’ (EN Pearce, Lancet, June 2011) _______________________________________________ XEmacs-Beta mailing list XEmacs-Beta(a)xemacs.org http://lists.xemacs.org/mailman/listinfo/xemacs-beta