The visitor pattern is relevant in multiple dispatch also; just most of its boilerplate goes away, so that only the visitation remains: traverse the AST (or wha

The visitor pattern is relevant in multiple dispatch also; just most of its boilerplate goes away, so that only the visitation remains: traverse the AST (or whatever structure) and invoke the given method with the node and visitor as arguments. For list in Common Lisp, the ancient mapcar function can do this: (mapcar (lambda (node) (visit node visitor)) node-list) We still have to write method specializations the different combinations of node and visitor types we need, for the generic function visit. (defmethoc visit ((left if-statement) (right print-visitor)) ... logic for printing if statement ) It's just less fragmented than the single dispatch version, because we don't have to perform two single dispatches to obtain one.