Documentation for method add_fallback assembled from the following pages:
Class: Metamodel::ClassHOW §
From Metamodel::ClassHOW
(Metamodel::ClassHOW) method add_fallback §
method add_fallback(, , )Installs a method fallback, that is, add a way to call methods that weren't statically added.
Both $condition and $calculator must be callables that receive the invocant and the method name once a method is called that can't be found in the method cache.
If $condition returns a true value, $calculator is called with the same arguments, and must return the code object to be invoked as the method, and is added to the method cache.
If $condition returns a false value, the next fallback (if any) is tried, and if none matches, an exception of type X::Method::NotFound is thrown.
User-facing code (that is, code not dabbling with metaclasses) should use method FALLBACK instead.