(If you a looking for a more general solution to this problem, hardhat-mode might be all you need.) Jumping to definitions with M-. is wonderful. The downside — everything has a downside — is that it is easy to accidentally edit a source file in the Quicklisp distribution. Here’s what I do. If you create …
Sometimes you want to write a macro that communicates information to macros inside of its compile-time “scope.” Pre-ANSI Common Lisp actually had a special form for this purpose, compiler-let, but it was removed in ANSI CL, and for good reason: what it did can be done entirely through the use of local macro definitions. This …
Sure, it’s nice to have exhaustiveness checking when dispatching on the type of a single object. But this is Lisp. What about multiple dispatch? Lisp already has a syntax for multiple dispatch: generic functions. Could you layer exhaustiveness checking on top of generic functions? Of course. But while many Lisp types have corresponding built-in classes, …
Continue reading “Exhaustiveness checking in Common Lisp, part 4: dispatch-case”