Question

Is there an easier and/or more readable way to create a closure in Ruby so that the defined method has access to the variable m?

I have a slight “problem” with the lambda here.

Very often I dynamically define methods that have to access a local variable:

For example:

class Comparison

  def income
    123
  end

  def sales
    42342
  end

  # and a dozen of other methods

  # Generate xxx_after_tax for each method
  instance_methods(false).each do |m|
    lambda {
      define_method("#{m}_after_tax") do
        send(m) * 0.9
      end
    }.call
  end
end

Answer 1

class Comparison

  def income
    123
  end

  def sales
    42342
  end

  # and a dozen of other methods

  # Generate xxx_after_tax for each method
  instance_methods(false).each do |m|

    define_method("#{m}_after_tax") do
      send(m) * 0.9
    end

  end
end