Feature request: Point in Time as a virtual dependency

Hi,

this is a feature request.

When declaring a filetask

file somefile => someother do
   do_something
end

it is executed only if either somefile does not exist, or one of the dependencies is newer.

But quite often I have requirements to not have a file get too old, which is not exactly straightforward in Rake.

Proposal:

Allow to define a point in Time to work as a virtual dependency, e.g. something like

d=DateTime.now.prev_month

file somefile => d do
  # recreate the file
end

to not let the File get older than the given date. Should be easy to implement.

regards

この issue ではファイルもテストも指定されていません。まず、Rake の file-task の依存関係処理と既存のタイムスタンプ比較を探し、その後、DateTime 依存関係をそのモデルにどのように適合させるかを判断してください。完了条件には、例に対して定義された動作と、point-in-time 依存関係のカバレッジを含める必要があります。