2007/4/17, Hernan Wilkinson <hernan.wilkinson at gmail.com>:
>
> >
> > Additionally Chronos also supports nominal time and leap seconds.
>
>  Maxi Taborda is enhancing Chalten adding that functionality... but is going
> to take some time :-) ...
>
> > > 5) Chalten is based on a arithmetic model that allows you to represent
> time
> > > measurements easily (like 3 days, 5 months, etc).
> >
> > That won't work in Squeak because these methods are already by the
> > Squeak Chronology (unless you have classboxes). It might work in VW
> > though.
>
> It works on Squeak,  VW, VisualAge, Dolphin and GemStone that are the
> Smalltalk were Chalten has been migrated to. Look at Aconcagua, the model
> that takes care of this.

I loaded Aconcagua-mx.1.6 and Chalten-mx.1.3 in Squeak 3.9. The
following all give errors:

GregorianDay today + 1 day
GregorianDateTime now + 1 day
GregorianDay today next: 5
GregorianYear current + 1 year
5 months

I guess I have to thank you. After hearing what a piece of shit
Seaside is because of its lack of documentation it's relieving to see
a framework with no class comments at all. A quick browsing through
same classes showed also no method comments.

Cheers
Philippe

> > > These objects are
> > > polymorphic with numbers respect to the arithmetic messages such as +,
> -, *,
> > > etc., that means that you can use them in arithmetic formulas
> >
> > That's true to a certain extent in Chronos for example you can:
> > Timepoint now - (CalendarDuration months: 1)
> > (CalendarDuration months: 1) * 5
> > but you can't:
> > 5 * (CalendarDuration months: 1)
>
> Ok, but it is not only the functionality what it is important for us... for
> us it is also important the way you "write" these things... for example,
> with Chalten/Aconcagua you can write:
>
> 5 * month ---> Equivalent to 5 * (CalendarDuration months: 1)
> 5 * meter / (second * second) --> A measure of acceleration if you create
> meter as a unit using Aconcagua
> 1/10 * year --> Represents an interest rate of 10% yearly.
>
> As you can see, time measure are not only related only to the time domain
> but used in other domains... that is way for us it is important to support
> this type of behavior and in a DSL way...
>
> Bye,
> Hernan.
>
> > > 5) And of course, I like Chalten's model more that Chronos :-). For me
> it is
> > > easier to use, but this is just a matter of taste...
> > >
> > > There is a paper we wrote 2 years ago about the problems that the
> Smalltalk
> > > date classes have and the advantages of having a better model. If you
> are
> > > interested on having better date and time classes, I recommend you to
> read
> > > the paper... you may not like it, but at least you will see other people
> > > ideas...
> > > We use that model (Chalten) in a production system and we believe it
> allowed
> > > us to avoid many common mistakes related to financial systems.... but
> hey,
> > > that's just a feeling, nothing I can prove formally.
> > >
> > > I hope you can do something useful.
> > > Bye,
> >
> > Chronos is a bit ugly in Squeak because Squeak does not support
> > namespaces which means that classes that model the same concept as
> > Squeak Chronology classes have different names (unless you mess with
> > shared pools). Also loading it is a bit of a pain with Monticello
> > (this is the fault of Monticello and not Chronos).
> >
> > Cheers
> > Philippe
> >
> > > Hernan.
> > >
> > >
> > > On 4/16/07, J J <azreal1977 at hotmail.com> wrote:
> > > > I have looked at Cronos but it is really huge, and the classes that
> come
> > > > with the image are already very close.  I will have to look at
> Chalten,
> > > but
> > > > what is wrong with a few upgrades to the classes that come with
> Squeak?
> > > >
> > > > >From: "Hernan Wilkinson" <hernan.wilkinson at gmail.com>
> > > > >Reply-To: The general-purpose Squeak developers
> > > > >list< squeak-dev at lists.squeakfoundation.org>
> > > > >To: "The general-purpose Squeak developers
> > > > >list"< squeak-dev at lists.squeakfoundation.org>
> > > > >Subject: Re: Date classes
> > > > >Date: Mon, 16 Apr 2007 14:28:09 -0300
> > > > >
> > > > >Before doing something with Date, I recommend you to take a look at
> > > > >"Chalten" or "Cronos". Chalten is in SqueakSource.... I think Cronos
> too.
> > > > >
> > > > >Hernan.
> > > > >
> > > > >On 4/16/07, J J < azreal1977 at hotmail.com> wrote:
> > > > >>
> > > > >>Hi all,
> > > > >>
> > > > >>I am doing some stuff with dates and I noticed the date classes that
> > > come
> > > > >>with the default Squeak image are very nice and very close to having
> > > > >>everything I would want.  But there are a few inconsistencies here
> and
> > > > >>there, and things missing that would make things easier.
> > > > >>
> > > > >>So what is the procedure to updating this?  I think it's part of the
> > > core
> > > > >>system so I probably can't just do a monicello package update
> > > > >>somewhere?  Do
> > > > >>I have to do it through mantis?
> > > > >>
> > > > >>Thanks,
> > > > >>Jason
> > > > >>
> > > >
> > >
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