How do I iterate through a hash where I can view the next key also?

Question

I have a hash of dates to money, and I need to put new money deposits inbetween a set of dates.

so, lets say my hash is

{"000000001" => "0.00", "000000002" ="12.34", "000000010" => "5.95"}

and I want to insert 000000008, 54.34 then my resulting hash should be

{"000000001" => "0.00", "000000002" ="66.68", "000000010" => "5.95"}

*(These are example time stamps)

so... I was thinking something like...

my_hash.each_with_index do |key_value, index|
  if index == my_hash.length then return my_hash end
    if time >= my_hash[dat[0]][0].to_i and time <= my_hash[dat[0]].next[0].to_i
      my_hash[index][1] += value
    end
  end
end

which I know is invalid, but I need help. Thanks!

Answer 1

facets probably has something like what you proposed. You can get the previous key like

previous = nil; a.each_key{|k| p 'key is', k, 'previous is', previous; previous = k}

Answer 2

Use each_cons:

{
  "000000001" => "0.00", "000000002" => "66.68", "000000010" => "5.95"
}.each_cons(2) do |(prev_key, prev_value), (next_key, next_value)|
  p "#{prev_key} preceedes #{next_key}"
end