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

El issue no menciona archivos ni tests. Empieza localizando la gestión de dependencias de file-task de Rake y su comparación de marcas de tiempo existente; después, determina cómo encajaría una dependencia DateTime en ese modelo. La finalización debe incluir un comportamiento definido para el ejemplo y cobertura para la dependencia point-in-time.