[Courses] [Ruby] Lesson 2: Iterators

[jennyw]

Anne G wrote:

>What I wanted was three independent objects which did their
>bit and told each other when to get started, but in the
>actual implementation, it does not work I think because the
>three objects are not actually independent. Each time we
>call on an object, we tie a know which we have to untie at
>some point.
>  
>
Hi, Anne,

I went back and read through your e-mails ... I wasn't sure what you're 
trying to accomplish with the three objects. Is this an abstract example 
or is there a practical application? It looked very abstract to me, so 
it was hard to figure out what you're trying to accomplish.

Going back, I see you were asking how to send messages to objects. You 
just do it like this ... object.message. For example,

fruits = ['apple', 'pear', 'banana'] #  an array of fruits
fruits.first     # send the message #first to the fruits object. it 
returns a string: 'apple'
fruits.first.class # you can also send two messages in a row -- for 
example, this sends #class to 'apple'. It'll return the class, String.

You also asked how can you can have two objects that do things and ask 
each other to do something. I see that you have the objects calling each 
other, and some recursive methods, but this is all implementation -- 
what I'm not clear on is the problem that this is the proposed solution 
for. I don't think this is so much a Ruby thing as it is a design 
issue.  It could well be that there's a design pattern that matches 
exactly what you want to do -- if we figure out what that is, it should 
be a lot easier to show it in Ruby.  I guess the first step might be to 
come up with a practical example (i.e. a user story). You might have 
done this, of course, and I may have missed it, so apologies if that's so.

Good luck!

Jen