Is there analogue for this ruby method?

Question

Recently I've came up with this method:

module Enumerable
  def transform
    yield self
  end
end

The purpose of method is similar to tap method but with the ability to modify object.

For example with this method I can change order in an array in chain style:

array.do_something.transform{ |a| [a[3],a[0],a[1],a[2]] }.do_something_else

Instead of doing this:

a0,a1,a2,a3 = array.do_something
result = [a3, a0, a1, a2].do_something_else

There are also another conveniences when using this method but...

The method is very straightforward, so I guess somewhere should be the already built method with the same purpose.

Is there analogue for this ruby method?

Answer 1

You can do that with instance_eval:

Evaluates (…) the given block, within the context of the receiver

Example:

%w(a b c d).instance_eval{|a| [a[3], a[0], a[1], a[2]] }
# => ["d", "a", "b", "c"]

or using self:

%w(a b c d).instance_eval{ [self[3], self[0], self[1], self[2]] }
# => ["d", "a", "b", "c"]