IFEM | IFEM - Isogeometric Toolbox for the solution of PDEs | Math library

I am not aware of a built-in functionality of that kind. However, such kind of feature is not hard to build from scratch, as long as other parts of OOP are not required (i.e., inheritance and other dispatching orders).

If you would never call (call-next-method) in you method-labels code (as you won't do in labels code, it is just a matter of defining a dispatch table and dispatch "methods" accordingly. To break it down, it should be a local macro that:

1. defines a local variable (gensym) as the dispatch table;
2. registers functions as closures together with its specialized lambda list into the dispatch table;
3. register a local "generic" function, that when called, find the function to call from the dispatch table according to the parameters supplied.

And to find the function, you may or may not need to:

1. sort the dispatch table (but if there is not eql specifier nor inheritance, this can be avoided)
2. write dedicated code to match against the specialized parameters for &optional, &key, and other options of the lambda list (or you can use destructuring-bind, but you'll need to transform the specialized lambda list into a lambda list) - there might be tools for that, but I am unaware of.

In the simplest case where the number of parameters in the lambda list is fixed, the dispatch can be as plain as a few (e)typecase.