From: "Lipper, Matthew" <Mlipper@...>
Date: 2006-12-02T03:36:52+09:00
Subject: Re: Timers, scheduling and Ruby

> 
> On 12/1/06, ara.t.howard@noaa.gov <ara.t.howard@noaa.gov> wrote:
> > On Fri, 1 Dec 2006, Pit Capitain wrote:
> >
> > > ara.t.howard@noaa.gov schrieb:
> > >> how bout this as the time spec?
> > >>
> > >>   http://runt.rubyforge.org/
> > >
> > > Ara, this would be nice, but I think it's difficult to 
> determine the time of
> > > the next event with Runt's temporal expressions. I'm sure 
> you don't want to
> > > call Runt::TExpr#include? every n seconds.
> >
> > indeed.  this is the only major design flaw.  still, if one 
> assumes a
> > granualrity of not more than 60s (ala cron) then this 
> approach isn't too bad.
> > between the dates/include methods one can determine apriori 
> if an event should
> > be scheduled for the next minute 'tick'.
> >
> > i'm assuming there is either a solution implied in the code 
> or that one can be
> > added without too much trouble - the bulk of the work has 
> already been done in
> > this lib, so even if it isn't there now, i'm sure a 
> solution will present
> > itself.
> >
> > now.  what do you suggest?
> >
> 
> Runt looks nice. Another package is Chronic. It was part of the
> natural language processing presentation at RubyConf this year. All
> Chronic does, though, is take human "fuzzy" times and turns them into
> actual Time objects.
> 
> Chronic.parse "next Thursday at seven am"    #=> Time object
> 
> http://rubyforge.org/projects/chronic/
> 
> What is needed to make Runt work for a scheduler is a next_time method
> that would return the next Time that this event should happen given
> Time.now. The scheduler then maintains a queue of the "next time" for
> all events and pulls them from the queue in order. When an event runs,
> the last thing it does is pulls the next_time from Runt and adds that
> to the queue (in the proper location). The scheduler thread then
> sleeps for N seconds where N is the time till the next event in the
> queue needs to happen.
> 
> So, maybe a combination of Chronic (to get the nice human readable
> format) and Runt (to keep track of recurring events) would work?
> 
> TwP
> 
> 

I'm still catching up to this thread but FWIW I am always interested in
making Runt more useful and functional. If I understand the above
correctly, then you'd like a next_time method returning a
Date/DateTime/Time (or whatever) that indicates the next occurrence of
this expression?

Matt

__mlipper__at__gmail_dot_com__