Can you elaborate on the reason why want to modify behaviour? And how you would like it to happen? If the code you want to modify is your own code than you can solve that most of time with the things you already have. Your example using a block might be altered to be a strategy pattern. That means you keep one ore more instance variables for strategy objects. Then you delegate parts of your behaviour to those objects. You can based on context exchange those objects to adjust behaviour. If it is not feasible to change the internal state of an object but you know all possible variants you can implement all variations as methods in the object. The right method can be invoked by doing a double dispatch with another object providing contextual information. There are plenty of possibilities so you need to know what is the context that is responsible for switching behaviour and the requirements of the behaviour modifications. Can you alter the object? Is the number of modifications a fixed number? Does the modification need to be thread safe?
Norbert > Am 23.07.2016 um 00:41 schrieb Eric Velten de Melo <ericvm...@gmail.com>: > > Hello, > > One thing I try to do often is changing the behaviour of a method dynamically > at runtime. The current way I do this is by having a block as an instance > variable and having the method call this block, but I find this approach a > bit cumbersome. Is there some other way or is this the recommended approach? > > I mean, I suppose methods could be changed dynamically by means of reflection > somehow, but is this an easy or recommended way of programming in Smalltalk? > Should slots make things easier? > > Eric
