gistfile1.rb

# This is how it looks

def calc_price(foo)
    price = nil
    ["list1", "list2"].each do |list|
      price_lists = lookup_price_lists # more logic but irrelevant for example
      price = get_price_for(price_lists, foo)
      return adjust_price(foo, price) unless price.nil?
    end
    price
end

Right now the code will look for a price in 'list1' or 'list2' and then exit as soon as it finds
a price.

I think there should be away to write that in a more 'functional' way. Right now I'd say it's quite
imperative.

One way is to 'map' 'lookup_price_lists' on the collection but I don't want that to be done if the 
method would have already exited in the previous implementation.

i.e. it shouldn't lookup prices for 'list2' if we've already got a price for 'list1'