FAQ Database Discussion Community

Custom slot options don't apply any reduction to its argument

Say if I define a metaclass that enhances standard slots with a validator slot, when I pass :validator (clavier:valid-email "The email is invalid") as an option, instead of storing the result of of the expression, which is a funcallable, it stores the expression itself. Am I'm missing a step when...

How do I best save/read data structures?

I want to write some data structures pointed to by FOO and BAR to a file, and to read the data structures back into the symbols FOO and BAR when I start a new session of Common Lisp. It would appear *PRINT-READABLY* allows objects to be printed in a fashion...

Common Lisp Object System method execution order

I have the following two classes: (defclass person () ()) (defmethod speak ((s person) string) (format t "-A" string)) (defmethod speak :before ((s person) string) (print "Hello! ")) (defmethod speak :after ((s person) string) (print "Have a nice day!")) (defclass speaker (person) ()) (defmethod speak ((i speaker) string) (print "Bonjour!"))...