Scala claims than OO and FP can be combined. I wonder how this can be achieved in practice. I mean object can change, so making them immutable means i have to create a new object whenever something changes right? This doesn't seem too effective to me.
By the way, if i make external reference to an object property from a function, doesn't it hurts referential transparency?
Don't think of this as one paradigm imposing restrictions on the other but as how can one take the best of both paradigms.
As a simple example:
Objects have functions which can be internal to an object. Now the internal functions can be immutable within an object and those results of a function can be used to change the state of a object.
Thinking at a different level one can use functions to create a library that can be used by objects.
How I like to make the best of both is I tend to make libraries (modules) for the more abstract processing using a functional language and then use OO languages for the layers closer to human and external processing. This is not a hard and fast rule but a guideline from where I start.
