crafting (and) JavaScript

Discovering ruby #3

This article about closures in ruby started somewhere by saying "Ruby has four different ways of using closures, each of which is a tad bit different, and sometimes nonsensical".

Finally a number that nails it. Now I know there are four ways of building closures (or at least that's the number it was in 2008).

To start off, we re-opened the Array class and put our iterate! method inside. We will keep with Ruby conventions and put a bang at the end, letting our users know to watch out, as this method might be dangerous!

Very interesting bits in here for me:

  1. "re-open the Array class" - that's what it is called when a class gets monkey-patched (again)
  2. a bang at the end of a method marks it as dangerous. Finally a very explict definition of what it means.

Later in the article I learned about the difference between a block and Proc. While this is still sinking into my brain, I think I will revisit this more often, in order to decide what to use when:

Block: Your method is breaking an object down into smaller pieces, and you want to let your users interact with these pieces.
Block: You want to run multiple expressions atomically, like a database migration.
Proc: You want to reuse a block of code multiple times.
Proc: Your method will have one or more callbacks.

And finally this article covers lambda and the ruby method method which (in my words) creates a reference to an existing method.

Very good article to learn about closures in Ruby. When I get the hang of how Ruby ticks inside I think this will be way more rational to me, it is not yet.