a message send consists of two steps:
- lookup the message implementation
- activate (i.e. call) the method that was found in this way
those are done in one step, not visible to the programmer
in Python, those steps are separated in the language:
obj.method(argument_1, ..., argument_n)
is identical to:
m = obj.method m(argument_1, ..., argument_n)
- The object
mis called a bound method - it can be called like a function
- it is bound to the object out of which it was read
- the bound method thus takes one less argument than the original method
- thus reading methods out of objects behave like object-attributes