Question

I can create a block that will extract hash elements and turn them into local variables, but I’m wondering if a native method already exists. Something like this:

extract({ :foo => 'bar', :foo2 => 'bar2' })
puts foo  # 'bar'
puts foo2 # 'bar2'

Note that the keys are private, and that the scope needs to stay local.

Answer 1

You can get close:

bar, bar2 = h.values_at :foo, :foo2

Or I suppose we could extend Hash to extract into instance variables:

class Hash
  def extract o
    each { |k, v| o.instance_variable_set '@' + k.to_s, v }
  end
end

h.extract self

p [@foo, @foo2]