Question

I have code like this:

class Foo

  # (method definitions)

  def make_hash
    {
      some_method: some_method,
      some_other_method: some_other_method 
    }
  end

end

How could I simplify, or DRY, make_hash? I want something like slice or Rails’ attributes.slice, but applying to methods of a regular class.

Answer 1

One way would be to create the hash with a default value block:

def methods_hash
    @methods_hash ||= Hash.new {|hash, key| hash[key] = self.class.instance_method(key) }
end

So, each time you request the hash’s key, it will dynamically load the instance_method without having to front load it all. The instance_method method returns objects, so you might want to .to_s or .to_sym to suit your needs.

I’m intrigued by the question though and would be interested in knowing what your end goal is with this method.