support for new private syntax

[fgarcia]

Since Ruby 2.1 this new syntax is valid to define private methos

private def map(attribute, to:)
  @rules[attribute] = to
end

However, currently the cop EndAlignment complains in this case

[bbatsov]

That's not actually a new syntax. It's just a side effect from the fact that in 2.1 def returns the method name. I'm not sure what's the best way to approach this. I'm definitely not particularly fond of this code layout as it seems cluttered to me and it would require a private for each method.

[jonas054]

I think I like the new way of using private that 2.1 adds.

In this book Clean Code, Robert C. Martin writes that "Concepts that are closely related should be kept vertically close to each other". He also talks about the "Newspaper metaphor", which means that the important stuff should come first in a class, and smaller and smaller details further down.

If you follow this style, you write a public method that calls some private methods. These private methods come directly after the public method. Then comes the next public method. If a private method is called from several methods, it's placed after the last call. All calls are downwards in the file.

That's how I like to write code and in languages like Java, C++, and Python it's natural to do so. Ruby is biassed towards having all the public methods first and all the private methods last. You don't have to, but that's what we do because it seems easier (easier than using private :my_method1, :my_method2).

[bbatsov]

Personally, I'm fond of grouping the public methods together, but I understand your point. In Java I'd occasionally place related private methods right after the public method that uses them. That said, I don't understand about the point about C++, since when I was a C++ programmer about a decade ago methods had to be grouped there more or less the same as they are in Ruby (in public, private, protected sections).

Anyways, I guess we can allow this indentation style if it's simple enough to do so. I'm also worried about the editor support for this indent style. I guess now most would indent the code like this anyways:

private def map(attribute, to:)
          @rules[attribute] = to
        end

As the def in the argument to private some might argue that this indentation is more "correct".

[jonas054]

About C++ (a bit off-topic for this project). It's only in the class definition (where you usually just declare the methods, normally put in a header file) that you have sections (public/protected/private). The method implementations can come in any order.

About the indentation in editors. Good point!

[fgarcia]

Personally I do love being able to refactor out small private functions from my code and leave them next to the related code. Also I think it should look like:

        private def map(attribute, to:)
          @rules[attribute] = to
        end

Maybe it is just a matter of taste, but leaving so much indentation space, will eat a lot of screen. Wouldn't it be better just one single indent level, like a normal function? Visually it would match with other functions on the same namespace. Even using a block of private/protected does not use an extra indent to keep its functions at the same level as the others

According the Ruby style guide:

https://github.com/bbatsov/ruby-style-guide

Indent the public, protected, and private methods as much the method definitions they apply to.

so why not do the same for their content?

As far as editor support, it is no longer an issue for Vim users, or at least... a closed issue: vim-ruby/vim-ruby#190

[bbatsov]

@jonas054 Emacs support for this is brewing :-)

[jonas054]

That makes me very happy.

[jonas054]

Getting back to the issue at hand... I'll update EndAlignment to enforce the style in @fgarcia's example when private, protected, public, or module_function is on the same line as def. Not configurable. OK?

[bbatsov]

Yes.

On Thursday, January 16, 2014, Jonas Arvidsson [email protected]
wrote:

Getting back to the issue at hand... I'll update EndAlignment to enforce
the style in @fgarcia https://github.com/fgarcia's example when private,
protected, public, or module_function is on the same line as def. Not
configurable. OK?

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/730#issuecomment-32545573
.

Best Regards,
Bozhidar Batsov

http://www.batsov.com

[bbatsov]

Btw, Emacs support for this is now merged upstream and will be part of the upcoming 24.4 release.