Goops Manual (original) (raw)

Node:Handling Invocation Errors, Previous:Determining Which Methods to Apply, Up:Invoking Generic Functions

3.7.2 Handling Invocation Errors

When an application invokes a generic function, and no methods at all have been defined for that generic function, GOOPS calls theno-method generic function. The default method callsgoops-error with an appropriate message.

When an application applies a generic function to a set of arguments, and no methods have been defined for those argument types, GOOPS calls the no-applicable-method generic function. The default method calls goops-error with an appropriate message.

When a generic function method calls (next-method) to invoke the next less specialized method for that generic function, and no less specialized methods have been defined for the current generic function arguments, GOOPS calls the no-next-method generic function. The default method calls goops-error with an appropriate message.