How to Check Slots Types at make-instance

from blog Lisp journey, | ↗ original
In CLOS, a slot can have a :type option, but it doesn’t inforce type checking. It is good practice to use it, for documentation and for compiler optimizations and warnings sometimes (with CCL and SBCL when safety is high), but one shouldn’t rely on it. To comply this need, we can simply create our own constructor functions. However, the...