morgan.rb

#!/usr/bin/env ruby

input = {
  foo: [ 1, 2],
  bar: [ 3, 4]
}

num_args = input.values.first.size

output = []

num_args.times do |index|
  new_hash = {}
  input.each do |key, value|
    new_hash[key] = value[index]
  end
  output << new_hash
end

puts output.inspect
#=> [{:foo=>1, :bar=>3}, {:foo=>2, :bar=>4}]