When to use blocks

Question

I love Ruby blocks! The idea behind them is just very very neat and convenient.

I have just looked back over my code from the past week or so, which is basically every single ruby function I ever have written, and I have noticed that not a single one of them returns a value! Instead of returning values, I always use a block to pass the data back!

I have even caught myself contemplating writing a little status class which would allow me to write code like :

something.do_stuff do |status|
  status.success do 
    # successful code
  end

  status.fail do
    # fail code
    puts status.error_message
  end
end

Am I using blocks too much? Is there a time to use blocks and a time to use return values?

Are there any gotchas to be aware of? Will my huge use of blocks come and bite me sometime?

Answer 1

I like this style. It's actually very Ruby-like, and often you'll see projects restructure their code to use this format instead of something less readable.

Returning values makes sense where returning values makes sense. If you have an Article object, you want article.title to return the title. But for this particular example of callbacks, it's stellar style, and it's good that you know how to use them. I suspect that many new to Ruby will never figure out how to do it well.

Answer 2

This is what functional programming people call "continuation-passing style". It's a valid technique, though there are cases where it will tend to complicate things more than it's worth. It might be worth to relook some of the places where you're using it and see if that's the case in your code. But there's nothing inherently wrong with it.