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Your examples are nice and educating in what is possible. Your code definitively promotes reuse and DRY.

My concern is understandability/readability/overengineering. Examples 8 and 9 are easily readable. Example 10 and 11 are worse. In Ex 8 you needed 1 class, which did all things. In Ex 10 you need MovieAction, Selector, Finder(?) and in Ex 11 all those subclasses.
I’m struggling to find justification for that complexity. How about adding some rationale, when this design should and shouldn’t be used.

Oleg

class CreditCalculator
{
//The return could be a Limit Entity object that provides at the minimum
//a useful toString implementation. It could also be used to control the
//underlying storage type

public double calculateLimit(double balance)
{
//the calculation can be more complex here using multiple
//members of the account.. for e.g. age of the account could be
//a factor.. thats why I had an Account object before

return balance *2;
}
}
.
.
//somewhere in my payment processing logic..
.
double creditLimit = creditCalculator.calculateLimit(myAccount.getBalance());
if(creditLimit

Thank you for the comments and the example.

I would ask why do you need the Limit as this will shape how the East/Right approach applies ?

Why does calculateLimit() take an Account?

What if CreditCalculator took an initial value and some function to call when it had the calculated value ? eg: calculateLimitThenCall(100, thingToDo)
(Please excuse my naming which Im making verbose)

Supposing there is another object that has the responsibility of assessing the credit limit for individuals based on the balance they have on their account?

The conventional way of doing it for an example would be.

class CreditCalculator
{
public Limit calculateLimit(Account acct)
{
return new Limit ( acct.getBalance() *2);
}
}

Thanks
Sriram

Thank you for the comments.

Dynamically typed languages do make an East approach easier, but I’m still surprised by how many people still don’t go east when using them.

With regard to ambiguity, I’m not sure I understand you point as East required all functions are 1.) void or 2.) return this/self. I think the “ask” problem creeps in when it isn’t one of these. Can we discuss further?

Rgs, James.

As for the text of this draft, I would like to see the East/West distinction be clarified a bit to say that the object they refer to is never the self/this object but rather anOtherObject (otherwise the “tell, don’t ask” type of ambiguity creeps in).

http://en.wikipedia.org/wiki/Continuation_passing_style